Ask A Master Gardener

Dutch Elm Disease is Devastating for American Elm Trees

noreply@blogger.com (Ask A Master Gardener) — Sun, 02 Aug 2020 19:54:00 +0000

Tom Ingram: Ask A Master Gardener

Sunday, August 2, 2020

Q: I have an American Elm that started looking like it had a problem and then died a few weeks later. What in the world happened? JA

A: The culprit was likely Dutch elm disease. I was speaking with Jen Olson of the OSU Plant Disease & Insect Diagnostic Lab recently and she said she was seeing more Dutch elm disease this year than in recent years, which is too bad because it’s one of the most destructive tree diseases in North America.

Dutch elm disease was first discovered in the Netherlands in the early 1900s, but it didn’t take long for it to make its way to the U.S. It arrived around 1930 on beetles who were hitching a ride on some logs headed our way to make furniture.

Quarantine helped control the disease until 1941, but the nation then became more focused on fighting a war. Some estimates suggest there were approximately 77 million elms in North America in the early ’30s. By 1989, more than 75% of those trees were lost.

Dutch elm disease grows in the xylem of the tree. The xylem is the tissue that helps bring water up from the roots throughout the entire tree. You typically start to see evidence of Dutch elm disease in the upper branches with leaves gradually browning, then yellowing and eventually getting dry and brittle.

When adult elm bark beetles emerge from under the bark of infected trees in the spring, they are covered with the Dutch elm disease fungal spores. They look for tender young bark on healthy trees to feed upon. Their feeding leaves wounds that become great places for the Dutch elm disease to take hold.

If you suspect your elm may have Dutch elm disease, you can cut off a branch about 1 inch in diameter from an actively wilting section, peel back the bark and look for discoloration similar to that in the photo (the dark strips). To be sure, you can bring a sample to your local Extension Office, and we will send it off to OSU for positive diagnosis.

If you catch the disease early, the infected areas can be pruned out, but you will need a minimum of 8 to 10 feet of un-infected, streak-free wood below the infected areas.

Fungicides and insecticides are available to help prevent Dutch elm disease; however, these chemical treatments should be applied by a licensed arborist because a fungicide may need to be injected into the tree. You can find a licensed arborist for our area at treesaregood.org.

There are a variety of elm species that are resistant to Dutch elm disease, but none is immune. Resistant varieties include Siberian elm, Chinese or lacebark elm, “Valley Forge,” “Princeton,” “New Harmony” or “American Liberty’.”

Garden tips

Now is the time to divide and replant crowded hybrid iris (bearded iris). When planting, take care not to plant the rhizomes too deeply. Cover them with an inch of soil or less. Do not mulch iris.
Water all plants deeply and early in the morning. Most plants need approximately 1 to 2 inches of water per week. Rather than watering daily, water less often and more deeply.
Some trees, such as sycamores and river birches, lose large numbers of leaves in the heat of summer. Trees do this to reduce water loss from their leaves. It is a coping action by the tree; it is not dying.

Bagworm Prevention Requires Proper Timing

noreply@blogger.com (Ask A Master Gardener) — Sun, 19 Jul 2020 14:31:00 +0000

Brian Jervis: Ask a Master Gardener

Sunday, July 19, 2020

Q: I have bagworms all over my arborvitae. What can I do to get rid of them? JG

A: Bagworms seem to be everywhere this year. Getting rid of them can be a challenge, but it is possible if you are up to the task. First, let us talk about the bagworm life cycle because understanding their life cycle is key to controlling them.

To begin, let’s go back a couple of months. Bagworm larvae overwinter in the bag and begin to emerge in late April or early May. Once emerged, these larvae begin to feed and construct the bags with which we are familiar. Initially, these bags may be only ¼ of an inch in length. But, as the larvae feed and begin to grow, they increase the size of the bag. This feeding is what can cause damage to the host plant. You mentioned arborvitae, but they also like eastern red cedars and junipers. However, in peak seasons, they can make their homes on pines, spruce, bald cypress and others.

For the female bagworms, the bag is their forever home. They do not develop wings, legs, eyes, or antennae and are almost maggot-like in appearance. Adult females can grow to about 1 inch in length. Males on the other hand grow to become small black moths that have a wingspan of about 1 inch.

Pupation occurs within the bag, and in the late summer or early fall, the males emerge from their bags in search of females. Adult males and females have a short lifespan — the female, a couple of weeks; the male, only a couple of days so the search is on. Neither the adult female nor male feeds. After mating, the adult female lays several hundred eggs within her bag and then dies. The eggs overwinter within the bag only to start the cycle all over again the following year.

So back to your question of what to do about them. With bagworms, timing is everything. When they are in their bags, about the only thing you can do is to remove them by hand, and you can do this any time of year. If your shrub is of an appropriate size, this is a good strategy, one the kids might enjoy helping with as well. Once the bags are collected, they need to be destroyed or placed in a sealed bag in the trash.

About the only other time you have a shot at control is in April and May when the larvae are feeding. During this time, you can spray with an organic pesticide called Bacillus thuringiensis or Bt for short. This organic pesticide only affects feeding caterpillars. You spray the pesticide on the infested plant, they ingest the pesticide while eating and die. Spraying this time of year while the bagworms are in their bags will not be an effective strategy as the bag does a great job of protecting them from harm.

Typically, damage is minimal from bagworms. However, infestations that build up over time can be detrimental to the health of your plant. So taking appropriate action at the appropriate time is key to bagworm control.

Get answers to all your gardening questions by calling the Tulsa Master Gardeners Help Line at 918-746-3701, dropping by our Diagnostic Center at 4116 E. 15th St., or by emailing mg@tulsamastergardeners.org.

Garden tips

· When watering your lawn, ornamentals, or vegetables, always do so in the morning if possible. If watered in the evening, plants will go into the night still being moist. Most disease-causing organisms need moisture, and because they grow best at night, leaving leaves wet in the evening will promote many plant diseases.

· Bulb onions are ready to harvest when the tops fall over. They should be removed and allowed to dry in a well-ventilated, shaded area. After the tops are completely dry, they may be stored in a cool, dry area.

· Tall, spindly tomato plants with scarce fruit are usually due to either too much nitrogen fertilizer or too much shade.

The Many Myths of Epsom Salts

noreply@blogger.com (Ask A Master Gardener) — Mon, 06 Jul 2020 14:27:00 +0000

Tom Ingram: Ask a Master Gardener

Monday, July 6, 2020

Q: I keep seeing posts online that recommend adding Epsom salts to the soil when planting tomato plants. Is this something I should be doing? JE

A: The internet seems to be abuzz with many near-miraculous claims attributed to Epsom salts. Before we talk about those, let’s talk about Epsom salts and a bit of soil chemistry.

Epsom salts is magnesium sulfate. Magnesium is one of the secondary nutrients found in healthy soil, and Epsom salts can be utilized as a soil additive if you have a magnesium deficiency. However, magnesium deficiencies are not common in home gardens.

Magnesium deficiencies can be found in soil that has been under intensive production over an extended period or in soil that has experienced a great deal of nutrient leaching due to excessive rainfall or irrigation. In this instance, adding magnesium would be an appropriate strategy to remedy a magnesium deficiency.

Potassium is one of the big three soil nutrients (nitrogen, phosphorus and potassium), and high levels of potassium in soil can interfere with magnesium uptake, but adding additional magnesium to the soil will not overcome the problem created by an abundance of potassium.

On the flip side, adding magnesium to soil that is not deficient in magnesium can interfere with potassium uptake, which may result in a potassium deficiency in plants even if the soil has adequate potassium supply.

Rather than continue to dig deeper into soil chemistry, let’s look at some of the claims we often see associated with adding Epsom salts to your gardens.

1. Epsom salt helps with seed germination.

Seeds have all the nutrients they need to germinate within the seed and can germinate in a wet/damp paper towel. Epsom salts does not aid in this process.

2. Put a scoop of Epson salts into each hole when planting tomatoes to prevent blossom end rot.

Blossom end rot is a common malady in tomatoes that is caused by a calcium deficiency. Adding Epsom salts when planting tomatoes not only does not help prevent blossom end rot but also can contribute to its occurrence because magnesium and calcium compete for uptake into the plant. An abundance of magnesium present in the soil will encourage less calcium uptake, thus increasing the potential for blossom end rot.

3. Use Epsom salts as a foliar spray to help tomato plants grow and enable a larger harvest of better-tasting fruit.

Again, this is unnecessary unless you have a magnesium deficiency.

4. Epsom salts are highly soluble so you can’t overuse it.

Epsom salts are in fact highly soluble; however, unnecessary nutrients applied in excess typically become a pollutant as they will be washed out, landing in unwanted areas.

5. Epsom salts can help plants grow bushier.

This would be true if you have a magnesium deficiency but not true as a general all-purpose additive.

So how can you tell if you have a magnesium deficiency? Magnesium helps with the production of chlorophyll so plants grown in magnesium-deficient soil will lose their deep green color and their ability to photosynthesize. Therefore, if you are seeing yellow leaves with stunted growth, you may have a magnesium deficiency. But remember, this is not common in home gardens.

If you have concerns about a magnesium deficiency in your garden soil, before you start adding Epsom salts, you should get your soil tested by the OSU Extension (be sure and say you want your secondary nutrients tested also) but know, we rarely find a magnesium deficiency in residential soil tests. Best strategy … save your Epsom salts for your bath.

Garden tips

• Vigorous, unwanted limbs should be removed or shortened on new trees. Watch for forks in the main trunk and remove the least desirable trunk as soon as it is noticed.

• Most varieties of mums are more productive if “pinched back” now. Either pinch off with fingers or cut to remove an inch or so of limb tips above a leaf. This results in the growth of new limbs and a fuller plant. Do not pinch after mid-July or it will interfere with fall blooming.

• Watch for tiny, sap-sucking insects called aphids on roses, perennial flowers, shrubs and vegetables (especially tomatoes). They produce a sticky substance called “honeydew”. Many can be dislodged with a hard spray from your garden hose or 2 applications of insecticidal soap will usually greatly reduce any aphid damage to your plants.

• Crapemyrtles are one of the few shrubs that should be planted in the middle of summer. Growth of new roots of these plants occurs best with summer soil temperatures.

Now is the Time to Start A Fall Vegetable Garden

noreply@blogger.com (Ask A Master Gardener) — Sun, 05 Jul 2020 15:21:00 +0000

Fall Vegetable Gardening

Brian Jervis: Ask a Master Gardener

Sunday, July 5, 2020

Q: I have heard good things about fall gardening but know nothing about it. When can I start and what can I plant? JP

A: For many gardeners, gardening is a year-round adventure, not just something we do in the spring and summer. And as summer is starting to hit full steam, now is the time to start planning and getting ready for your fall garden.

When we talk about fall gardens, we split fall garden vegetables into two categories: tender and semi-hardy. Tender vegetables will not make it past the first frost. Semi-hardy vegetables can endure several frosts and keep producing.

Tender varieties, such as pole beans, bush beans, cilantro, eggplant, peppers, pumpkin, squash and tomatoes, among others, can be planted starting around mid-July.

Semi-hardy crops can be planted a little later. These would include beets, broccoli, Brussels sprouts, cabbage, potatoes, etc.

Fall gardening has several advantages. One of those is that you can get some of the best quality vegetables from your plants due to the warm days and cool nights later in the season. Another advantage comes from the fact that some of the insects we have been battling won’t be as much of a problem due to the timing of their life cycle. But it’s not all fun and games because we still have July and August to deal with.

In the spring, we are challenged with cold soil temperatures so many of us start our seeds indoors and move the plants outdoors when the soil has warmed up. In the fall, we do the same thing but for opposite reasons: We start our seeds indoors so they can germinate in cooler conditions and then move the plants outdoors.

Direct seeding becomes problematic for fall gardens and may require extra effort on your part due to high soil temperatures. Exposed soil on a hot day in July and August can warm up to 140 degrees. This presents challenges to direct seeding as these high temperatures will prevent germination. If you do direct seed, you will need to protect those tiny seeds by using a thick layer of mulch or perhaps covering them with shade cloth to help keep the soil cooler.

We have a great fact sheet on our website that gives you a list of veggies you can grow in your fall garden, as well as information on when to plant, how to plant and number of days before harvest. You can find it in our Hot Topics section on our homepage.

Also, if you are new to gardening or just want to learn more, you can sign up for our Online Urban Gardener classes and learn about soil, vegetable gardening, pollinator gardens, trees and shrubs, and turf management. Info on these classes can be found by clicking on the Urban Gardener link on our homepage at tulsamastergardeners.org.

Good luck and happy gardening.

Get answers to all your gardening questions by calling the Tulsa Master Gardeners Help Line at 918-746-3701, dropping by our Diagnostic Center at 4116 E. 15th St., or by emailing mg@tulsamastergardeners.org.

Garden tips

Divide and replant crowded hybrid iris (bearded iris) after flowering until August. When planting, take care not to plant the rhizomes too deeply. Cover them with an inch of soil or less. Do not mulch iris.
Water all plants deeply and early in the morning. Most plants need approximately 1 to 2 inches of water per week. Rather than watering daily, water less often and more deeply.
Some trees, such as sycamores and river birches, lose large numbers of leaves in the heat of summer. Trees do this to reduce water loss from their leaves. It is a coping action by the tree; it is not dying.

Good Garden Practices Prevents Problems

noreply@blogger.com (Ask A Master Gardener) — Tue, 23 Jun 2020 14:10:00 +0000

Good Garden Practices

Tom Ingram: Ask a Master Gardener

Tuesday, June 23, 2020

Q: It seems like there is always something wrong in my garden. If it’s not insects, it’s some sort of disease. What am I doing wrong? JK

A: It can seem like that sometimes but let us talk a little bit about disease prevention rather than just how to deal with disease once it happens.

Resistant plants and seeds:

If you start your vegetables from seeds, purchase disease-resistant seeds. If you are like most people, you will say, “How the heck do I do that?” Well, most vegetables have varieties that are more disease resistant than others. Heirlooms (for example) are typically traditional cultivars that have been passed down from generation to generation that remain true to their heritage. As such, they can be more susceptible to disease because they do not have the advantage of having disease resistance bred into them via hybridization. Hybrids are not GMOs; they are varieties that have been cross-pollinated with other varieties to either increase production, increase disease resistance or both. For example, seed packets for tomatoes indicate their disease resistance with the letters V, F and N. Seeds with those disease-resistance indicators would be naturally resistant to Verticillium Wilt, Fusarium Wilt and Nematodes. So right from the start, you are ahead.

Also, try to purchase healthy plants. As gardeners, we all know that the bargain table with the sickly looking plants can be tempting. But try to remember these plants are there for a reason. The reason might be disease. If you cannot resist (and many of us can’t), try to keep them away from your other plants until you nurse them back to health.

Crop rotation

If you plant tomatoes in the same spot every year, disease pathogens can build up in the soil, becoming a bigger problem each year. To counteract this, you can rotate your crops. Some people rotate every year, but for sure, it’s good practice to rotate at least every three years. But here is the trick; you need to learn about the vegetable families because vegetables in the same family are usually susceptible to the same diseases and you might be surprised by who is in the same vegetable family. Tomatoes are in the solanaceous family, so are potatoes, eggplant and peppers. So if you are going to rotate your crops, don’t plant potatoes where the tomatoes were. Brassicas include broccoli, cauliflower, Brussels sprouts, kale, radishes, etc. Legumes include the bean family. And the others kind of make sense. So rotate by family, not just vegetable.

Garden practices: You need to be aware of how your garden practices might be contributing to plant disease. First, you should water in the morning. When you water in the morning, the water can evaporate off the plant and soak into the soil before the heat of the day. Watering at night can leave the leaves of your plants wet, and wet leaves are more prone to disease. Also, be sure to water the roots, not the leaves. The roots need the water, the leaves do not.

And clean your tools. If you have been trimming or pruning infected branches or leaves, wash your tools with a 10% bleach solution to prevent spreading the disease to other plants.

If these habits become part of your garden practices, you will be well on your way to minimizing plant disease and being a happier gardener.

Garden tips

· White grubs will soon emerge as adult June Beetles. Watch for high populations that can indicate potential damage from grubs of future life cycle stages later in the summer.

· Fertilize warm-season grasses at 1 pound Nitrogen per 1,000 square feet. Do not fertilize fescue and other cool-season grasses during the summer. Because nitrogen is soluble in water, much of it may have been lost due to percolation and runoff if you fertilized before recent rains.

Squash Vine Borers

noreply@blogger.com (Ask A Master Gardener) — Sun, 21 Jun 2020 14:47:00 +0000

Brian Jervis: Ask a Master Gardener

Sunday, June 21, 2020

Q: My squash plant was big and beautiful, and then one day, the leaves started turning yellow and in a few more days it was dead. What happened? RW

A: The culprit was likely the squash vine borer. These insects can be a problem for all cucurbit plants and are the reason many of us no longer grow squash but grow cucumbers instead. Yes, I know cucumbers are cucurbits too, but they don’t seem to bother cucumbers like they do the squash.

Squash vine borers overwinter in the soil as either larvae or pupae. Adult moths begin to emerge in June (possibly sooner if we have a mild winter like we have had) and remain active through August.

During this time, they find a mate. The female deposits her eggs, usually about a dozen or so at a time, on the stem of the squash plant near ground level. The eggs hatch and the larvae enter the stem to begin feasting on your beautiful squash plant. They essentially eat out the inside of the stem, destroying the plant’s ability to draw up nutrients into the rest of the plant.

Signs of this not only include the yellowing and wilting of the leaves on your squash plant, but you will also see something that looks like wet sawdust on the stem of the plant. This is the excrement (frass) of the borer inside of the stem.

These larvae continue to feed for four to six weeks and can migrate to other plants if their host plant dies or ceases to become suitable for their needs.

These borer larvae are white or cream colored and can be easily seen by slicing open the vine in the affected area. The fully grown moth is primarily black and orange and is easily mistaken for a wasp.

Squash vine borers are worthy adversaries and controlling them can prove difficult. The first line of defense will require diligence on your part. This entails visually inspecting your plant stems near the soil line for eggs. If eggs are found, they can be destroyed.

If you missed the eggs and are seeing evidence of the squash vine borer (frass), you can gently slit the stem and remove the larvae. Once removed, you should cover the damaged part of the stem with soil. With any luck, you will continue to get production from your plant.

Weekly preventative applications of an organic insecticide during the active months can also help. An organic pesticide like spinosad should be applied to the stalk of the plant near the soil level during their period of activity. But be careful to only spray the base of the stalk and spray late in the evening, as you don’t want to harm any of the pollinators working on your behalf to get you some squash.

As an alternative strategy to weekly pesticide spraying, pheromone traps can be placed in your garden near your squash plants. When the squash vine borer moth shows up on your trap, you know it is time to begin spraying the stalks near the soil with spinosad.

And last but not least, because squash vine borers overwinter in the soil, tilling the soil at the end of the season can help disrupt their life cycle.

Good luck!

Garden tips

· Remain alert for insect damage. Add spider mites to the list. Foliage of most plants becomes pale and speckled; juniper foliage turns a pale yellowish color. Shake a branch over white paper and watch for tiny specks that crawl. Watch for first-generation fall webworm.

· Some pests can be hand-picked without using a pesticide. Do not spray if predators such as lady beetles are present. Spraying insecticides early in the morning or late in the day will avoid spraying honeybees and other essential pollinators.

Soil Tests Help Select a Fertilizer

noreply@blogger.com (Ask A Master Gardener) — Sun, 07 Jun 2020 14:19:00 +0000

Tom Ingram: Ask a Master Gardener

Sunday, June 7, 2020

Q: With all the different fertilizers out there, how do I know which one I should be using? AR

A: Fertilizers can be confusing. They come in a variety of strengths with a variety of numbers and for the beginner or novice, it can be overwhelming. So let’s break it down.

The fertilizers you find at the store have a series of numbers on the bag. These numbers can be something like the following: 10-20-10, 19-19-19, 3-17-17, 31-0-4, 46-0-0, etc. Those numbers coincide with the percentage of nitrogen, phosphorus, and potassium in each particular product. So, if a product says it is 10-20-10, that means it contains 10% nitrogen, 20% phosphorus and 10% potassium. If it says 46-0-0, that means that it contains 46% nitrogen, 0% phosphorus and 0% potassium.

So how do you know which one you should use?

The best way to know for sure is to have your soil tested. This may sound a little intimidating, but it is a simple process.

First, you will need to collect the soil sample. You can collect this sample using a specialized soil sampling tool or just use a garden trowel. A bulb planter works well also. The trick is to get between 15-20 samples from the area you want tested. These samples need to contain soil to a depth of 6 inches. If this is your yard, get 15-20 samples from various points in your yard, put them in a bucket, mix it up, remove the twigs and fill something about the size of a sandwich bag from the soil in your bucket. If you are wanting a soil test for your vegetable garden or your flower bed, get your 15-20 samples from those areas.

Once you get your soil sample in a bag, bring it to the OSU Extension office, 4116 E. 15th St. Even though the office is closed, there is a black mailbox on the south side of the building (in the back) where you can fill out a form and leave your sample. There is a $10 charge for a soil test. We will pick it up and forward it to OSU, where they will test for pH, nitrogen, phosphorus and potassium. Once tested, you will get a recommendation on what nutrients are needed for your situation. These recommendations will vary depending on what area you are sampling and what you are growing.

Once you have the results of your soil test, you will know how much of each nutrient you need to add to your soil for best results.

So back to the fertilizer. Let us say the test revealed your soil only needed nitrogen, and it was recommended that you add 1 pound of nitrogen for every 1,000 square feet. In this case, you could purchase some 46-0-0 fertilized because it is 46% nitrogen and does not contain phosphorus or potassium. This means that if each pound of fertilizer is 46% nitrogen, you would need about 2 pounds of fertilizer to give you 1 pound of nitrogen. If you purchased 10-20-10, you would need 10 pounds of this fertilizer to give you the 1 pound of nitrogen. Plus (in this case) you would be purchasing phosphorus and potassium that you didn’t need and which might also be harmful to your growing environment.

Yes, you may need to use a calculator, but odds are that getting a soil test will not only be good for your soil but also will ultimately help you save money by not having to purchase nutrients you don’t need.

Garden tips

•Do not work soil if it is too wet. Tilling it while wet will cause damage to the structure and it will take a long time to recover.

•Thatch is a layer of dead and living stems, shoots and roots which pile up on top of the soil at the base of lawn grasses. If it is over ½ thick it should be removed with either a core-aerator or power-rake. Now is the time to de-thatch Bermuda and zoysia. De-thatch fescue, if needed, in the fall.

Non-infectious Tomato Problems

noreply@blogger.com (Ask A Master Gardener) — Thu, 04 Jun 2020 22:00:00 +0000

Brian Jervis: Ask a Master Gardener

Thursday, June 4, 2020

Most of us have had our tomatoes in the ground for a while and are looking forward to some delicious fruit soon. However, our journey from planting to eating typically comes with a few challenges.

Tomatoes can be persnickety. Everything has to be just right to get fruit and then when things are going great, along comes an insect or a disease to frustrate your efforts.

We will talk about some of those issues in future articles, but first, let us talk about noninfectious diseases in tomatoes because most of these are the result of some sort of environmental challenge.

Blossom drop: Here is the scenario. Our plants are in the ground, we are getting flowers, and we are looking forward to those flowers developing into fruit. But instead, those flowers fall off and drop to the ground … thus the name “blossom drop.” Typically, we see blossom drop when we have settled into regular daytime temps above 90 degrees, as this heat inhibits pollination.

However, cooler temperatures can also contribute to blossom drop when our night temperatures are below 55 degrees. We have had weather like that recently, and some of you have been experiencing blossom drop due to cooler temperatures. However, once it warms up, you should begin to get fruit on your tomatoes.

Blossom-end rot: Blossom-end rot is pretty easy to spot when you notice the blossom-end of your tomato turning brown. Gradually, the brown spot gets bigger, is sunken and feels somewhat leathery. This area of the fruit then becomes susceptible to pathogens that result in the fruit rotting.

Blossom-end rot can be the result of several different factors; high temperatures, wind, fluctuating water availability and drought can all promote blossom-end rot. But so can excessive soil moisture for prolonged periods of time. These conditions inhibit the plant’s ability to draw up calcium from the soil, and so blossom-end rot is ultimately the result of a calcium deficiency.

However, adding calcium to the soil is not a solution to the problem because no matter how much calcium you add to the soil, the environmental conditions have not changed, and the plant is still not able to lift those nutrients up into the plant.

There are a lot of solutions online to blossom-end rot suggesting putting eggshells in a blender and sprinkling them around your plants. This will eventually add calcium to your soil, but it will not help solve the blossom-end rot problem, only time and drier conditions will do that.

Catface: Catfacing is an interesting one in that it shows up as misshapen fruit with what appear to be scars. Again, this is another temperature-related problem that can occur when temperatures are below 58 degrees when the flower is being formed. Turf-weed pesticides that contain 2,4-D can also be a contributor if they come in contact with your plant.

These are some of the main noninfectious disease problems we see in tomatoes, but you can learn about more on our website (tulsamastergardeners.org) by looking in our Lawn & Garden Help section under vegetables.

Garden tips

• Yellow leaves on plants may be due to too much water in the soil. With the deluge of recent rain and the subsequent saturation of the ground, some plants may show damage, often yellow leaves on the lower part of plants. This occurs both in ornamental and vegetable plants.

• Commonly, yellowness is due to lack of iron or nitrogen in the soil. However, when the soil is saturated with water, oxygen is forced out of the air spaces and the roots suffocate. This prevents them from absorbing nutrients, resulting in the yellow appearance. As the soil dries out, this problem will correct itself.

• Some pests can be hand-picked without using a pesticide. Do not spray if predators such as lady beetles are present. Spraying insecticides early in the morning or late in the day will avoid spraying honeybees and other essential pollinators.

Master Gardeners Educational Activities

noreply@blogger.com (Ask A Master Gardener) — Sun, 24 May 2020 13:31:00 +0000

Master Gardeners Educational Activities

Brian Jervis: Ask a Master Gardener

Sunday, May 24, 2020

So much of what we do as Master Gardeners involves community engagement. We teach classes, we speak at various civic groups, we have exhibits at community events, we staff our Diagnostic Center at the OSU Extension, and we teach elementary school students about horticultural issues, among other things.

All that came to an abrupt halt a few weeks ago. Like most of us, Master Gardeners have had to learn new ways to help our community during this time.

With so many new gardeners in our midst, we have struggled with how to best help you. Let me tell you a little bit of what we have started to do to help bridge the gap between social distancing and the community needs for horticultural education.

First of all, for kids, we started our new online Fun Pages for Kids. On each fun page, there is a short video, a trivia game, and a coloring page.

We have three Fun Pages currently and hope to release a new one each week, at least through the summer. Current Fun Page topics include one about the lifecycle of Monarch butterflies, honeybees, and worms. The Fun Pages can be found through a link on our homepage: tulsamastergardeners.org.

For the grownups, we have migrated our popular Urban Gardener training classes to an online format for now.

In this series, there are six sessions covering almost everything you need to know to become a more successful gardener. Topics include soil, growing vegetables, pollinator gardens, trees and shrubs, and turf management.

Each session includes an instructional video, links to supplemental materials and additional videos for those who want to dive deeper.

We miss the in-person classes but think these online classes will be helpful for at least the near future.

While the OSU Extension may be closed, soil testing is alive and well with a little bit different process. At this time, soil for soil tests can be dropped off at the extension without human contact.

At the back of the OSU Extension building, there is a black drop-off box with instructions on how to leave your soil sample. We will pick them up and get them to OSU for testing.

It typically only takes about two weeks for you to get your results with recommendations on how to amend your soil properly.

Even though our Diagnostic Center is closed to the public, we are continuing to check the phones for messages and our email account for questions. Each call and email will be answered like always, just not in real-time.

Also, for the next few weeks, we will be live on our Facebook page from noon to 1 p.m. Thursdays to answer your gardening questions. If you are a Facebook person, join us during lunch with a question on the Tulsa Master Gardener’s Facebook page.

We hope everyone stays safe and is using this time to up their gardening game.

Garden tips

· Clean out water garden and prepare for season. Divide and re-pot water garden plants. Begin feeding fish when water temperatures are higher than 50 degrees.

· Plant warm-season vegetable crops, such as watermelon, cantaloupe, cucumber, eggplant, okra, sweet potatoes, etc., now.

· Fruit trees, especially apples and peaches, must be thinned out for best production. Prune apples 4-6 inches apart and peaches 6-8 inches. This will ensure larger fruit and less damage to limbs. If not thinned, the tree's resources will be used to such an extent that next year’s crop will suffer.

Fungal Rust Disease of Pears and Many Other Trees

noreply@blogger.com (Ask A Master Gardener) — Thu, 14 May 2020 17:14:00 +0000

Rust Diseases on Pears and Others

Tom Ingram: Ask a Master Gardener

Thursday, May 14, 2020

We break from tradition today and are not going to answer a single question but rather address a topic that has been flooding our Diagnostic Center via phone and email: fungal diseases in trees and shrubs. And when I say flooding, I mean flooding.

This spring has been cool and moist for the most part and still is. These are perfect conditions for fungal diseases in plants.

There are a variety of fungal diseases with a variety of names, but in my book, the most interesting one is rust disease. There are several rust diseases: cedar-apple rust, Asian pear rust, cedar-hawthorn rust and cedar-quince rust, to name a few. These diseases are not extremely harmful but can be detrimental to the vigor of both hosts, as well as diminish the productivity of fruiting trees.

One thing that is interesting about these diseases is that they bounce back and forth between different plants with the common link being the cedar (aka juniper). This year, it seems like almost every pear tree in town (including Bradford pears) is covered with Asian pear rust.

While this explanation can seem a little like “which came first: the chicken or the egg,” let’s give it a shot.

The spots we are seeing on pear and apple tree leaves this spring are the result of fungal spores that have blown from a nearby cedar. Nearby is a relative term and typically means within a mile or so, maybe more.

The fungal spots on the apple and pear leaves mature somewhere around June or July. Once mature, they begin to release their own spores, which are then blown by the winds in hopes of finding a cedar to call home.

Asian pear rust causes fairly small rust twig cankers on the cedars, while cedar-apple rust causes small galls to be formed. Fast forward a few months and spring rains cause these cankers to release their own spores, which go out in search of another broadleaf host. Lather, rinse, repeat.

While the Asian pear rust cankers are fairly small, cedar apple rust galls can be golf ball sized. But it gets better. When spring rains soak the cedar-apple rust galls, they begin pushing out these long orange gelatinous tendrils full of spores, which then ride the wind in search of a new home. It is quite a sight.

To control these diseases, the hosts need to be separated, but in town, that is next to impossible. So we are primarily left with treatment options.

Susceptible broadleaf trees, such as apples or pears, can be treated in the spring from the point their leaves emerge through April on seven- to 10-day intervals with a fungicide that includes one of the following ingredients: copper hydroxide, chlorothalonil, myclobutanil and propiconazole (use as specified on the labels). Cedars can be treated in late June-July with the same fungicides. However, you can always physically remove the galls from the cedars when you see them.

For fruiting trees, we recommend you follow a pesticide spraying schedule that can be found in the Hot Topics section on our website, tulsamastergardeners.org.

Garden tips

· Nutsedge weeds are emerging now. Post-emergent treatments are best applied for the first time this month. Make certain warm-season grasses have completed green-up. Nutsedge control requires specific treatment for control; standard broadleaved post emergent herbicides are not effective. Contact the OSU Tulsa County Master Gardeners for recommendations.

· Plant summer bulbs such as cannas, dahlias, elephant ear, caladiums and gladiolus.

· Remember, working wet soil will cause significant damage to the soil structure. Give it time to drain from recent rains, before tilling. Damage from tilling while wet may last for a very long time.

Powdery Mildew Affects Many Plants

noreply@blogger.com (Ask A Master Gardener) — Sun, 10 May 2020 17:01:00 +0000

Powdery Mildew

Brian Jervis: Ask a Master Gardener

Sunday, May 10, 2020

Q: Some of my plants are developing this white powdery substance on them. What is going on? AM

A: What you are describing is called powdery mildew and can occur on most ornamental plants such as crape myrtles, lilacs, photinias, zinnias, tall phlox, and others. Humid conditions over a variety of temperatures such as cool nights followed by warm days are conducive to powdery mildew growth. Have we been having any of those? Yes, we have. Younger growth also tends to be more affected.

The spores of this disease tend to overwinter on plant debris from the previous season. The spring awakens these dormant spores, which then begin making their way to your new plants. You will likely first notice powdery mildew on the leaves of your plants with them taking on a somewhat dusty appearance.

To prevent this disease from occurring, there are a few things you can do. First, give your plants some breathing room. Do not crowd them. The air circulation will help mitigate the conditions that encourage its development. You may even need to do some pruning to allow for greater air flow.

Also be mindful of when and how you are watering. The leaves of your plant do not need to be watered. The water needs to be placed on the root zone. Now, a lot of times there are sprinkler systems that are watering a large area at once and you cannot keep the water off the leaves. But if you are hand watering, water the roots, not the leaves.

Also, water in the morning. This allows time for water to evaporate off the leaves during the day rather than watering in the evening when water can remain on the leaves all night making a perfect breeding ground for disease.

You also do not want to fertilize your plants in late summer, which would encourage new growth that could become susceptible to powdery mildew.

If these strategies do not prevent development of powdery mildew, your plants can be sprayed with a fungicide or neem oil. Before spraying, remove as many of the infected leaves as is practical. You may say all the leaves are infected. If that is the case, do not remove all the leaves. But if the disease is limited to a certain area of the plant, then by all means, remove that branch or stem because you will be eliminating the source of the problem. You may need to repeat these treatments every two weeks for a while until you don’t see any more evidence of the disease. Chemical treatment will not repair damaged leaves, but it will stop its spread.

Garden tips

• Prune and feed all the spring blooming shrubs, such as azaleas and forsythia immediately after blooming, if needed. Azaleas need less fertilizer than many shrubs and often a yearly addition of mulch, as it decays, it will add all the nutrients they need.

• Seeding and sodding of warm-season grasses such as bermudagrass, Buffalograss and zoysiagrass is best performed in mid-May through the end of June. The soil temperatures are warm enough for germination and growth. These grasses need a long summer growing season to promote winter hardiness.

Mulching Plants is Important

noreply@blogger.com (Ask A Master Gardener) — Fri, 01 May 2020 14:55:00 +0000

Mulching Plants in your Garden

Tom Ingram: Ask a Master Gardener

Friday, May 1, 2020

Q: I have my vegetable transplants in the ground, now what should I do: DK

A: Congratulations on getting your young veggies in the ground. This is an exciting time. One thing you can do, maybe one of the most important things you can do, is surround them with a layer of mulch. Here is why.

Mulch helps your garden in a variety of ways; one of these is water conservation. A good layer of mulch surrounding your plants will directly correlate to how much time you need to spend watering. Mulch helps hold moisture in the soil by reducing evaporation, and water that does not evaporate is still available to your plants. Seems simple, but you would be surprised how many people don’t do this.

Soil temperature will also be much more consistent with a good layer of mulch. Research has shown that on a hot summer day, the temperature of your soil may rise as much as 30 to 40 degrees, while properly mulched soil temperatures may vary as little as 10 degrees during the same time period. A more constant soil temperature is going to help keep your plants happier and more productive. And to the previous point about water conservation, water evaporation will be much more consequential with a soil temp of 120 degrees than with a more comfortable 80 to 90 degrees.

A mulch barrier between the leaves of your plant and the soil will also help reduce disease. Many of the fungal diseases of vegetables originate in the soil. Without mulch, as it rains or as you water, these diseases can splash up from the soil onto the lower leaves, enabling the disease to find a place to grow. Mulch provides a barrier between the soil and the lower leaves, reducing this splashing and therefore reducing the opportunity for disease.

Additionally, mulch decreases the ability of weeds to grow in your garden because it covers the soil, discouraging those tiny, pesky weeds from breaking through to the outside world. Weeding must be one of my least favorite things, so anything that reduces my time down on my knees in the garden is golden in my book.

There are quite a few options concerning what type of mulch to use. Personally, I mow the leaves from my trees in the fall with a mulching mower. I bag them and save them till now when I can scatter them around my plants. However, I know that ship has sailed for many of you.

The primary recommendation on type of mulch is to use something organic, such as leaves, straw, cotton seed hulls, etc. We say this because most soil in our area is low on organic matter. If you use an organic mulch, it will deteriorate naturally and can be tilled back into the soil at the end of the season. This helps increase the organic matter in your soil, which is always a good thing.

For more information on different types of mulch and best practices, go to the Hot Topics button on our website (tulsamastergardeners.org) and click on the Mulching Garden Soil link.

Garden tips

· After moving potted plants from inside to outdoors, irrigate the pots with 2-3 pot volumes of water to remove salts that may have accumulated from fertilizers.

· Spring-blooming bulbs are best fertilized in fall and late winter when leaves emerge. After blooming, they go dormant and cannot use fertilizer applied at that time.

Bird Friendly Gardens

noreply@blogger.com (Ask A Master Gardener) — Mon, 27 Apr 2020 16:47:00 +0000

Bird Friendly Gardening

Tom Ingram: Ask a Master Gardener

Sunday, April 26

Q: Since I have been spending more time at home, I really enjoy watching the birds in my garden. What can I do to encourage more birds to visit? BG

A: Bird watching is great fun, and with time and some internet searching, it’s fun to learn all the different varieties that pay you a visit. However, birds are not only fun to watch, but also they provide a valuable resource in helping to control insects, so it’s a win-win.

Birds are like most of us when it gets down to it (and we have been reminded of this lately). Their primary needs are food, water and shelter. So, let’s look at each of these.

You can encourage birds to visit your garden by being sure there is something for them to eat. The easy way to do this is to add a bird feeder to your yard. To attract a variety of birds, fill your feeder with a seed mix that includes large and small seeds. Some birds, such as finches, will search out a specific type of seed. So if you want finches in your yard, you will need to get a feeder that is built for thistle.

However, you can transition from a feeder to a natural source of food by planting fruit or seed-bearing plants. Sunflowers are the first that come to mind. Tomatoes are another one if you are willing to share your tomatoes with the birds.

Some flowers are beautiful, like forsythia or lilac. However, they do not provide any food. Instead, for your bird sanctuary, you might want to consider a holly, whose berries are always a bird favorite.

Keeping your lawn healthy and vibrant is another attractor to birds in that healthy lawns encourage worms, and robins, mockingbirds and flickers all love worms.

Water is important for birds, just like humans. Typically, we think of a bird bath as a water source; however, water features, such as fountains, are also appropriate if they have a shallow area of no more than 2 inches. If you do have a bird bath, be sure to place a small rock in there to give them a place to stand. And remember, a standalone bird bath will need to be washed out every three to four days and disinfected with bleach once or twice a year.

There are a variety of ways to provide shelter for birds. Broken branches in a pile will attract cardinals, wrens, towhees and sparrows. Trees and shrubs with dense branches, leaves or perhaps thorns will also provide excellent shelter.

Plants such as honeysuckle or grapes are a double win in that they not only provide a food source but can also be used as shelter.

Vines on fences are also prime real estate for food, nesting and shelter. Clematis, honeysuckle and grapes would fit in this category.

One thing to remember if you install a bird feeder or bird bath is to place it at least 10 feet away from other trees or shrubs because birds are lower on the food chain than some of the other creatures that visit your yards.

Building a bird house is another topic, and you can find information on this and more on gardening for birds in a great fact sheet from OSU on landscaping for birds. You will find a link to it in the Hot Topics section of our website.

Good luck and stay safe out there!

Garden tips

· Lace bugs, aphids, spider mites, bagworms, etc. can start popping up in the landscape and garden later this month. Keep a close eye on all plants and use mechanical, cultural and biological control options first.

· Remove any winter-damaged branches or plants that have not begun to grow. Prune spring-flowering plants as soon as they are finished blooming.

· Proper watering of newly planted trees and shrubs often means the difference between success and replacement

Vegetable Transplants. When and How to Transplant

noreply@blogger.com (Ask A Master Gardener) — Sat, 18 Apr 2020 15:00:00 +0000

Vegetable Transplants. When and How to Transplant

Tom Ingram: Ask a Master Gardener

Saturday, April 18, 2020

Q: I am itching to get my little vegetable seedlings in the ground. Is it safe for me to do that now? DS

A: Every year, the question “when can I plant” comes up and, for us, the answer is always “after April 15th.”

There is no magic in that date other than it is Tax Day (except this year) and a special birthday around our house, which is always magical. But the reason we say April 15 is because this is historically the last of the days we tend to get a freeze.

Many of us want to jump the gun because it gets warm. I mean we even had a few days in the 80s recently. These warm days convinced a lot of us to go ahead and plant. But mother nature does what Mother Nature wants and now we have had freezing or near-freezing temperatures right before April 15. So, if you jumped the gun, you were likely out covering your plants to do your best to keep them safe from the freeze.

Looking at the weather right now, we should be good to plant our transplants this weekend…with a special emphasis on “should” and the caveat: have you hardened off your plants?

Hardening off is the process of preparing your veggie plants for their new life outdoors. You can begin this process while they are still indoors by using a rotating fan at low speed. The gentle breeze from the fan will help strengthen your baby plants and better prepare them to be outside.

Another thing they definitely need to ease into is getting used to the outdoor sun. One of the worst things you can do to your baby transplants is to take them from your house and plant them directly in the open garden. Their entire life (thus far) has been indoors in a controlled environment, so they need to get used to the sun gradually, not all at once. If you place them in the soil or a container outdoors without hardening them first, they will likely burn up and not recover.

To harden your baby plants, they need to be placed outside in a protected place, maybe an area that gets dappled or partial sun to start. But, don’t just put them out and forget them. Maybe start with a couple of hours on the first day and increase for an hour each day until they get used to the sun. Be sure to bring them in at night if it is cold. But after a couple of weeks of hardening, they should be ready to go out in your garden. If you follow these simple steps, your chances of having delicious veggies all season long are greatly increased. Good luck and happy gardening!

Garden tips

· Lace bugs, aphids, spider mites, bagworms, etc. can start popping up in the landscape and garden later this month. Keep a close eye on all plants and use mechanical, cultural, and biological control options first.

· Remove any winter-damaged branches or plants that have not begun to grow. Prune spring flowering plants as soon as they are finished blooming.

· Proper watering of newly planted trees and shrubs often means the difference between success and replacement

Master Gardeners Springtime Activities During ClOVID-19 Times

noreply@blogger.com (Ask A Master Gardener) — Sun, 12 Apr 2020 15:11:00 +0000

Brian Jervis: Ask a Master Gardener

Sunday, April 12, 2020

If there is any type of silver lining to be found in what we are currently going through, it will likely be found in doing things we have wanted to do and never done, or having the time to fan the flames of an old passion.

For many of us, that would include a desire to either start a vegetable garden or renew our efforts in that area. It’s a shame that it took a coronavirus to get us there, but perhaps this is also a lesson we will learn moving forward: Don’t put off the things that truly bring us joy. And for many of us, gardening is a great source of joy.

One thing that brings the Master Gardeners joy is our yearly plant sale. It is a lot of work, but we like nothing better than helping you get awesome flowers, veggies and herbs to take home to your garden. However, as you know, we had to cancel the plant sale this year so that we could do our part to help us all stay safe and healthy.

We even had to close our Diagnostic Center at the OSU Extension. But please know that even though it is currently closed, we are still at work answering your questions and providing the best gardening advice we can. How are we doing this, you might ask? Good question.

At the end of this article, you will see a phone number and email address for our Diagnostic Center. While we do not go into the office, we have Master Gardeners who are monitoring the phone messages and emails and responding to your questions in a timely manner Monday through Friday. In addition, we have our Facebook page where we share daily garden tips, as well as insect coloring pages for the kids.

Did you know we have a YouTube channel? Well we do, and it hosts our video podcast called Garden Talk. In each Garden Talk episode, we discuss a variety of topics, which usually include Pest of the Week, Plant of the Week, Right Now (advice on what to be doing in your garden right now) and answers to some of your questions. There are currently more than 50 videos there, including full episodes, as well as breakout videos on individual topics. To find them, go to YouTube and search Tulsa County Master Gardeners.

Last, but certainly not least, is our website (tulsamastergardeners.org). This site not only contains information on the various programs the Master Gardeners are involved with throughout our community, but also we have an extensive Lawn and Garden Help section that includes not only links to a variety of helpful garden topics, but also a lot of instructional videos.

So the Master Gardeners are still here to help you in a variety of ways. Good luck, stay safe, and maybe start that vegetable garden you’ve always wanted.

Garden tips

· Don’t spray insecticides during fruit tree bloom or pollination may be affected. Disease sprays can continue according to schedule and label directions.

· Mowing of warm-season lawns can begin now. Cutting height for bermudagrass and zoysia grass should be 1 to 1½ inches high, and buffalo grass 1½ to 3 inches high.

· Harden off transplants outside in partial protection from sun and wind prior to planting.

· Hummingbirds arrive in Oklahoma in early April. Get your bird feeders ready using 1 part sugar to 4 parts water. Do not use red food coloring.

Starting vegetable Sprouts from Seed

noreply@blogger.com (Ask A Master Gardener) — Sat, 28 Mar 2020 14:36:00 +0000

Starting vegetable Sprouts from Seed

Tom Ingram: Ask a Master Gardener

Sunday, March 29, 2020

Q: Now that I have more time on my hands at home, my kids and I were thinking of starting a vegetable garden. How should I get started? AJ

A: The situation we collectively find our community in is a bit scary, but what better way to social distance ourselves than working out in the garden? And it’s a great way to supplement our food, as well as a fun activity for your kids. Here are a few tips to help you get started.

First, you’ll need to decide what you want to grow. Good vegetables for first-time gardeners are tomatoes, peppers, cucumbers and bush beans. Potatoes are also a good choice. You can supplement these with some herbs, such as basil and oregano.

Seeds for these are available online if you don’t want to get out, or you could visit one of our local garden centers to pick up what you need. I am guessing that some of our local vendors would be more than willing to bring your order out to your car for you.

Of the crops we mentioned, it’s best to start your seeds for tomatoes, peppers, cucumbers and the herbs indoors, so you are going to need some type of container to plant your seeds. These can be as simple as used yogurt or butter containers or something more elaborate like the peat pot starters you can get at the store. Whatever you decide to use, it would be good to get some seed-starting soil. Seed-starting soil is much less course and is a great medium for starting new plants.

Next, fill your containers with the seed-starting mix, moisten it, and place a seed in each one. Move your newly planted seeds to a sunny, warm location, and wait. Germination times vary, but with any luck, you should see your plants start to emerge in a few days. Seed germination heating mats can speed up the process, but that may be something you what to think about for this fall or next year.

Be sure to keep your seeds well-watered without drowning them. In these small containers, it is easy to overwater, especially if you are using a container without drainage in the bottom.

The typical day we say you can plant your seedlings outside is April 15. This is historically after the last threat of frost has passed, but in Oklahoma, all options are on the table.

Seed potatoes can be planted now, and bush bean seeds should go in the ground after April 15.

Most gardeners started their seeds a few weeks ago, but better late to the party than never showing up. We have an entire page on our website about growing vegetables with resources that you should find helpful. Just go to tulsamastergardeners.org and click on the button marked Vegetable Garden Help.

Good luck and happy gardening!

Garden tips

· All cool-season vegetables, strawberries, asparagus and other small fruit may be planted this month.

· Established broadleaf weeds can easily be controlled in lawns at this time with post-emergent broadleaf herbicides. These herbicides are most effective in spring and fall when weeds are growing.

· Cut down dead pine trees as soon as possible. Most of these trees died of pine wilt disease due to a nematode infection. The infection is spread by the pine sawyer beetle, and dead pines are a source of infection carried by these beetles.

Growing Vegetables in Containers

noreply@blogger.com (Ask A Master Gardener) — Sun, 15 Mar 2020 14:52:00 +0000

Growing Vegetables in Containers

Tom Ingram: Ask a Master Gardener

Sunday, March 15, 2020

Q: I would love to have a vegetable garden, but we rent our home. Any suggestions? KT

A: This is a dilemma faced by a number of people whether you rent a home or an apartment. Fortunately, there are a number of options that will enable you to grow your own vegetables.

The best solution for your dilemma is container gardening. Almost any kind of container can be used to grow vegetables. The simplest would be a 5-gallon plastic bucket.

Just get a bucket, drill some holes in the bottom to allow for drainage, fill it with garden soil, and you are ready to go.

Buckets are great for tomatoes. There are even some smaller “patio” varieties of tomatoes that can produce all summer without trying to grow 6 feet tall.

You can also grow peppers, bush beans and any number of herbs, such as basil. You could even grow potatoes.

Fabric pots are another container option. These pots are typically made of a felt-like material and come in a variety of sizes. They even have handles on top to ease in moving them around. Many of us grow potatoes in these pots as we can start the potatoes in shallow soil and add soil as they grow. This helps increase your harvest.

Another great thing about containers is that they can be mobile. If you live in an apartment, you can move the container into the sun in the morning and then maybe place them in shade for that late-afternoon sun. Also, spring weather can sometimes be challenging for vegetable gardeners because we are likely to get a hail storm or two.

In case there is news of a hailstorm, you can just move your containers to a protected area. This is a luxury those of us with raised-bed gardens don’t have. These are not the only options, but at least these will get you started.

Garden tips

Remove flowers from spring-blooming bulbs after blooming is completed. This will allow the plant to direct its energy into its bulb for next year's blooms, rather than producing seeds.
Allow foliage of these bulb plants to die and turn brown naturally before removal. If the leaves are green, they are storing energy for the following year.
These bulb's root systems become inactive after blooming and cannot absorb fertilizer. It is best to fertilize them at the time of planting, in the fall or in the spring when their leaves first emerge
The Master Gardener Online Plant Sale continues through April 1.

Oklahoma Proven Plants for 2020

noreply@blogger.com (Ask A Master Gardener) — Sun, 01 Mar 2020 15:31:00 +0000

Oklahoma Proven Plants for 2020

Tom Ingram: Ask a Master Gardener

Sunday, March 1, 2020

Q: I have a friend who suggested I try some Oklahoma Proven plants. What is he talking about? BC

A: Oklahoma State University has a program called Oklahoma Proven, where plants are tested to see how well they perform in the somewhat unpredictable and oftentimes brutal Oklahoma climate. Each year, a variety of plants are evaluated, and several are selected to become that year’s Oklahoma Proven selections. The winners for 2020 are out. You may or may not be familiar with some of these, but any of them would be great additions to your garden.

The tree for 2020 is the Hornbeam (Carbines species). This tree does great as an understory tree and needs little pruning. It is slow growing and can be used as a tree or a hedge, typically reaching heights of about 20-30 feet. It grows well in full sun to part shade. Plant in a place with well-drained soils.

The shrub this year is the Red Yucca (Hesperaloe parviflora). This perennial has evergreen leaves from 2-3 feet in length while the flower stalks can rise up to 5 feet with coral-colored tubular flowers. It’s drought-resistant, and the flowers can attract hummingbirds. This one would be great for xeriscape or low-maintenance gardens.

The perennial for 2020 is the Golden Variegated Sweet Flag (Acorus griminess “Ogon”). This grassy plant is native to Asia and will do well in full sun to part shade but will appreciate some afternoon shade if planted in a full-sun location. Boggy or consistently moist areas are not a problem for this one. The Ogon cultivar is a dwarf variety that should grow to 6-12 inches tall, making it great for a border or an interesting filler plant.

The annual is the Brazilian Verbena (Verbena bonariensis). This plant usually has a 1-foot-tall base of dark green leaves with flower stems of up to 3½ feet. Even though it is technically a tender perennial, in Oklahoma it is considered an annual. If sheltered, it might survive the winter. Even if they don’t, they are self-seeding, so you may be able to enjoy them for years to come. It is heat- and drought-tolerant and has the added bonus of being a great attraction for pollinators.

Oklahoma Proven has been around for 20 years and has compiled a book that can be purchased or downloaded for free. Check under the Hot Topics link on our website if you would like a copy.

Garden tips

If you had previous damage to the tips of pine tree limbs, especially non-native pines, it may be diplodia tip blight (a fungus) or Nantucket pine tip moth damage. Both are controlled with pesticides starting this month. Call the Master Gardener office for recommendations.
Preemergent herbicide to control crabgrass and other summer weeds should be applied by the middle of March.
Divide and replant overcrowded, summer- and fall-blooming perennials. Mow or cut back old liriope (monkey grass) and other ornamental grasses before new growth begins.
The Master Gardener online plant sale continues through April 1.

noreply@blogger.com (Ask A Master Gardener) — Sun, 16 Feb 2020 14:42:00 +0000

Master Gardener Spring Plant Sale

Brian Jervis: Ask a Master Gardener

Sunday, February 16, 2020

Q: Each year, I have mixed results with flowers in my garden. Do you have any recommendations for what might work well in our area? AM

A: Success in the garden can sometimes feel so random, especially for new gardeners. On our website, we have several resources to help you make good choices for your garden, and you can always contact our Diagnostic Center with any questions you may have.

But a great resource with appropriate plants for your garden is our annual plant sale. In this sale, we offer varieties that have performed well in our gardens, and we should know, with about 400 Master Gardeners in Tulsa County.

This year, we have more than 250 varieties of plants in our online plant store listed by category to help you make selections that best meet your garden needs. These categories include annuals, perennials, tomatoes, herbs, succulents, stepables, grasses, pollinator plants and new this year — organic pollinator plants.

I am guessing most of you have been to Tulsa’s horticultural extravaganza (and awesome park), Gathering Place. Have you ever walked around Gathering Place, seen a beautiful plant and thought: “I wish I could have something like that in my garden?” Well, now you can. Working in conjunction with the horticulturalists at Gathering Place, we have identified 15 selections in our online plant sale that are part of the ecosystem at Gathering Place. So if you order some of these beauties, you can have a little piece of Gathering Place at home. We are pretty excited.

How does an online plant sale work? Well, the plant sale functions like other online shopping experiences. As you browse through the selections, you can click on a plant that interests you and read about that particular plant. The descriptions will tell you whether it does best in sun or shade or both or grows tall or grows small or just about any other piece of information you may need to make your selection.

Once you have identified the ones you can’t live without, proceed to the online checkout, pay, and this part is done. Then we begin to do the hard part: getting the plants ready for you.

Pick-up is from 9 a.m. to 7 p.m. April 16 in the Exchange Center at Expo Square. On this day, you just go to the Exchange Center, tell us who you are, drive around to the pick-up area, and we will load your flowers in your vehicle for you. How easy is that?

Also on that day, we will have a pop-up plant sale where you will be able to shop for additional varieties that would be great additions to your garden, including milkweed for the Monarchs.

All the proceeds from this sale go to help fund our educational programs throughout Tulsa County. To shop, just visit tulsamastergardeners.org. We appreciate your support and look forward to helping you make your garden even more beautiful.

Garden tips

Mid-February is a good time to begin pruning and fertilizing trees and small fruits.
Now is a good time to cut back your perennial ornamental grasses, such as pampus grass. Cut back to remove the dead grass but avoid damaging new buds and early green growth at the base.
Begin planting blackberries, raspberries, strawberries, grapes, asparagus and other perennial garden crops this month

Groundhog Day

noreply@blogger.com (Ask A Master Gardener) — Sun, 02 Feb 2020 16:52:00 +0000

Groundhog Day

Tom Ingram: Ask a Master Gardener

Sunday, February 2, 2020

In this article, we typically answer your gardening questions. However, I won’t even pretend that this installment sprang from one of your questions. Instead, it is the result of my getting curious about something, doing some investigating and wanting to share what I learned with you. Who knows? It may even help you win a trivia completion someday.

What topic might cause us to stray from the mission-at-hand? Groundhog Day, of course! So here are some facts that you may or may not know about groundhogs and Groundhog Day.

Did you know the groundhog is also known as the woodchuck, or my new favorite name, whistle pig? That’s right … whistle pig.

These extra-large rodents are mainly brown with strong legs and curved claws, perfect for digging. An adult groundhog can weigh between 6 and 10 pounds and grow to be 16 to 20 inches in length. That is a fairly sizable rodent. Groundhogs are primarily vegetarians that like to look for their food during the day. Spring is mating season and an adult female can give birth to four or five offspring.

In Oklahoma, they can be found along the edges of forests or perhaps near rocky bluffs and ravines. They are primarily in eastern Oklahoma, but have been sighted in Pawnee, Payne, Lincoln, Logan, Okfuskee, Pittsburg and Oklahoma counties.

They are a burrowing animal whose burrows can sometimes reach 30 feet in length. Burrows can have several chambers, including one used as a place to relieve themselves, which helps them to keep their living chambers clean and free of disease. I’m all for that. It is believed that they hibernate in Oklahoma for four to six months.

But how did this tradition of Groundhog Day get started, you might ask? Good question.

Feb. 2 is associated with a Christian tradition called Candlemas. There are deeper historical roots but suffice it to say that Feb. 2 became the day Christians would take their candles to the church to have them blessed. As far as we know, there was no animal associated with this European tradition.

However, German folklore tells us that at some point a ceremony with an animal was introduced and if the animal saw its shadow, there would be six more weeks of winter.

In the original German tradition, a hedgehog was used. However, as Germans migrated to this part of the world, there were no hedgehogs to be found, so the groundhog (aka whistle pig) became the weather prognosticator and central character in one of our more whimsical traditions.

So now you know.

Happy Groundhog Day!

Garden tips

Early February through March is the recommended time to plant strawberries. It is important to plant them in full sun and in well-drained soil. There are several types from which to choose. June-bearing varieties do best in our area. They have a single crop usually early May to mid-June. Ever-bearing strawberry is another variety that fruits May to June, a few during summer and again in the fall. The quality and size of this type of strawberry plant may not be as good as June-bearing varieties.

Planning a New Vegetable Garden

noreply@blogger.com (Ask A Master Gardener) — Sun, 19 Jan 2020 16:40:00 +0000

Planning a New Vegetable Garden

Brian Jervis: Ask a Master Gardener

Sunday, January 19, 2020

Q: This year, I am going to plant my first vegetable garden. Any suggestions? EC

A: Congratulations for deciding to take the plunge into growing your own delicious veggies. Your question is more than we can cover in this article, but here are some tips to get you started.

First, you will need to decide what kind of garden you are going to plant, as there are a lot of options.

If you are planning on doing what we call an in-ground garden, your first job will be to clear an area. This typically involves getting a soil tiller to loosen up the soil and get you started on removing the existing grass (no small task). The next step would be to get a soil test (we have instructions on our website at tulsamastergardeners.org).

Without a soil test, you are really flying blind in knowing how to amend your soil. A soil test will tell you the levels of nitrogen, phosphorus and potassium, as well as your soil pH. These are all important and will make a difference in how successful you are with your garden.

If you are not going to do an in-ground garden, you have a variety of options, the most popular being a raised bed or container garden. Because you are a beginner, we might suggest starting with a container garden. Almost any container can be used for this purpose. Just be sure there are holes in the bottom of your container to let the water drain or your plants will be sunk before you start.

Speaking of water, be sure to consider the proximity of a water source — the closer the better — because you are going to be spending a fair amount of time watering your plants to help them through our Oklahoma summers.

And, of course, you will have to decide what you are going to grow. We suggest growing what you are going to eat. If you only kind of like tomatoes, don’t plant a lot of tomatoes. This seems pretty obvious, but each year, some gardeners seem to be begging people to take some of their abundant tomato crop off their hands. Another vigorous producer is okra. It’s pretty easy to grow, and each plant produces an abundance of okra, so a couple of plants might be all you need for your home garden. You can find information on when to start your plants and which veggies do well in Oklahoma on our website.

Feeling overwhelmed yet? Well don’t be. Our Urban Gardener series of classes will be starting in a few weeks, and these classes can help you become a more successful gardener. The classes are from 6-8 p.m. Thursdays for six weeks starting March 5. Each evening, we will cover different topics, which include how plants grow, soil management, vegetable gardens, pollinator gardens, trees and shrubs.

You can sign up for these classes on our website. If you are interested, don’t delay because these classes typically sell out.

Good luck and happy gardening!

Garden tips

Even though there may be adequate moisture in the ground, it is normal for evergreen broad-leaved shrubs to appear “wilted” during extreme cold. This is rapidly reversible after the temperatures warm. This is a way some plants have in dealing with the cold.
Try to keep fallen leaves off newly seeded fescue. Fescue is capable of growing roots in winter unless the ground gets extremely cold. A good root system will help fescue to better tolerate the heat next summer. To grow roots, the grass needs sunlight.

Resolve to Grow A Better Garden This Year

noreply@blogger.com (Ask A Master Gardener) — Sun, 05 Jan 2020 17:45:00 +0000

Resolve to Grow A Better Garden This Year

Tom Ingram: Ask A Master Gardener

Sunday, January 5, 2020

First of all, Happy New Year. It’s a time of new beginnings, a chance to reflect upon the previous year and determine how we can do better this year.

It’s no different for gardeners. Last year, some of what we did worked, and some of what we did didn’t work. Our gardening successes were great fun, whether that was tending beautiful flowers or being the caretaker of delicious fruits and vegetables.

But gardening can be tough. Many things conspire against us, such as the heat, the cold, the rain, the lack of rain and the invasion of insects who think our garden was just for their nutritional enjoyment, etc.

But what about this year? What are we going to do differently? What are our gardening resolutions?

To find out the answer to that question, I polled the Tulsa Master Gardeners to see what their gardening resolutions were for 2020. Here is what they said (in no particular order):

• Do something in the garden every day so that the work doesn’t pile up.

• Don’t buy more plants until the last ones I bought are planted.

• Finally purchase the tools I have been needing.

• Clean and maintain my garden tools better.

• Keep a garden journal from year to year so that I can remember what worked and what didn’t.

• Do some stretches after being down on my knees for an extended time in the garden.

• Actually, have a plan for my garden rather than just buying all the pretty things.

• Try to stay ahead of the weeds.

• Actually, build in “garden time” into my day rather than just squeeze it in.

• Try some new plants rather than just do what I did last year.

• Divide some of my plants and share with friends so they, too, can have a jungle in their yard.

• Get a plan and stick with it.

• Lean more toward organic solutions.

So there you have it. You’re not alone. Surely, there is something, or maybe many things, on this list that resonate with your garden experience.

The Tulsa Master Gardeners not only feel your pain but also want to help you become a better gardener. Here’s some of the ways we can help:

• First of all, you’re reading one of those resources right now: the Ask a Master Gardener article in the Tulsa World. Stay tuned.

• You can also call our Diagnostic Center, drop by or email Master Gardeners from 9 a.m. to 4:30 p.m. Monday-Friday at the OSU Extension.

• Visit our website at tulsamastergardeners.org. We have an extensive website with an abundance of resources in our Lawn and Garden Help section.

• Attend classes. We teach classes throughout the year, such as our Urban Gardener series, our Lunch & Learn classes at the Tulsa Central Library and our classes at the Mother Road Market.

• Watch the videos. We have a new Garden Talk video podcast with lots of current and timely garden information for you. You can find it on YouTube, Facebook and on our website.

So, here’s to 2020. The year we keep our garden resolutions!

.Garden tips

Ornamental perennial grasses, such as pampas grass, may be cut back to 4-6 inches anytime in winter. However, because of winter attractiveness, most gardeners choose to wait until early spring to cut them back. All of the dead tops of these grasses should be removed by early spring, allowing sun to get to new growth.
Liriope or "monkey grass" — which is not a grass but in the lily family — stays green year-round; it also benefits from trimming to 2-3 inches before new growth begins in spring. Liriope and all ornamental grasses will benefit from nitrogen fertilizer in spring when pruned.
Prune fruit trees in January, February and March. OSU has a good fact sheet on pruning fruit trees, "Annual Pruning of Fruit Trees."

Pruning Trees and Shrubs

noreply@blogger.com (Ask A Master Gardener) — Sun, 22 Dec 2019 16:20:00 +0000

Pruning Trees and Shrubs

Brian Jervis: Ask A Master Gardener

Sunday, December 22, 2019

Q: I need to do some trimming and pruning on our trees and shrubs. Is now a good time to do that? MA

A: Pruning and trimming is an important part of keeping our trees and shrubs healthy as long as you know when to prune and how. It can also be a little tricky because now is the perfect time for some plants and not so great for others. Here are some general tips to help.

We prune for a variety of reasons: training and shaping the plant, thinning for better air circulation and health, removal of dead branches, stimulating new growth or flowers, or to keep plants away from our homes or other structures.

One thing to remember is to never remove more than about a third of the branches. If you do a good job pruning, your work will not be noticeable. It will look natural and not like you were trimming with a vengeance. This un-natural manner of trimming can be seen all over town in what we gardeners call “crape murder” (the over-aggressive trimming of crape myrtles you see in the photo and all over town).

Here are some general rules on when to prune.

Flowering trees, shrubs and vines typically should not be pruned in the winter as many of these set the flower buds for the next year in the summer. Most hydrangeas fall into this category (except the Oak Leaf variety). If you have not been getting flowers on your hydrangeas, have you been cutting back those dead-looking stems in the fall or winter? They can be a little unsightly, but the best time to prune these is after their blooming burst in the spring so they will have time to set buds for the following year. Other shrubs that fall into this category are flowering quince, forsythia, viburnum and wisteria.

Another group is the summer-flowering varieties, such as abelia, butterfly bush or Rose of Sharon. These should be pruned in the fall or early spring.

There is also a category of broadleaf evergreen plants like acuba, camellia, boxwood, cherry laurel, holly, mahonia, nandina and photinia. These are best pruned in the spring before new growth begins.

Tree trimming and pruning is typically best left to trained professionals. I know, a lot of us consider ourselves chain-saw warriors, but there is a difference between cutting up a branch that fell to the ground and successfully cutting that several hundred-pound branch off a tree. Typically, this type of work is better left in the hands of a trained arborist. Tulsa is fortunate to have several arborists to from which to choose. To find a good arborist, we suggest you visit treesaregood.org. This is the national database of arborists. Their website will help you find a local licensed arborist who will meet your needs.

We have an extensive list of different varieties of how to trim on our website. We also have a video on how to plants that include recommendations on when and properly trim crape myrtles. You can find this and more information on our website, tulsamastergardeners.org, by clicking the “Hot Topics” button on the home page. Good luck and stay safe.

Garden tips

· All birds need and appreciate clean feeders and unfrozen water on cold days. Place feeders close to protective shelter, if possible.

· Be sure to keep your Christmas tree watered to keep if from drying out.

· Light prunings of evergreens can be used for holiday decorations. Be careful with sap that can mar surfaces.

· Newly seeded fescue will continue to grow roots and make energy if you keep them free of leaves.

Poinsettia Care

noreply@blogger.com (Ask A Master Gardener) — Sun, 08 Dec 2019 15:09:00 +0000

Poinsettias: How to Achieve Re-Flowering Next Season

Tom Ingram: Ask A Master Gardener

Sunday, December 8, 2019

Q: Each year I purchase a new poinsettia and each year I end up throwing it away. Is there a way to keep it until next year? CH

A: Poinsettias are our favorite Christmas plant with sales of over $250 million dollars each year. That’s a lot of poinsettias!

Poinsettias are the namesake of Joel Poinsett, the first U.S. Ambassador to Mexico, who first brought these plants north to the United States. In their native Mexico, they are a perennial and can grow 10 to 15 feet tall making a beautiful shrub. In honor of Poinsett, Dec. 15 is National Poinsettia Day which coincides with the death of Poinsett in 1851.

Believe it or not, the poinsettia has also been known by several names; such as the Lobster Flower or the Flame-Leaf Flower due to the red color of its bracts (that is what those red leaves are called). But good luck walking into your local nursery and asking where the Lobster Flowers are. OK, so enough with the history lesson, let’s get back to the question.

As gardeners we hate to just throw away a potential new member of our garden tribe, but some plants kind of nudge us to move in that direction. If you want to try and keep your poinsettia alive while encouraging it to develop those beautiful red bracts next year, here is what you are going to need to do.

1) At the first of the year you should fertilize your poinsettia with a good all-purpose fertilizer and provide it with adequate sun and water indoors.

2) Sometimes the plants can become leggy, so around mid-February, trim it back to around 5” in total height.

3) Mid-March remove the dried and faded parts of the plant.

4) Mid-May (after the danger of a freeze is over), you can move the plant outside to a place that gets indirect sunlight. Keep them away from locations that get hot-drying winds. Trim the longer branches back about 2 or 3 inches to shape the plant into a rounded bushy plant. Be prepared to replant if it outgrows its container. Continue to water and apply a house plant fertilizer at the recommended rate.

5) In late September, bring the plant indoors and place it in a sunny location. At this point the plant needs to rotate between absolute darkness and sunlight to begin developing that bright red color. To accomplish this, leave them in the sunny location each day, but place them in absolute darkness from 5 p.m. each evening and leave them there till about 8 a.m. Follow this daily procedure daily for about two months and you should you get good red bract color, typically by Thanksgiving.

Or, you could do what most of us do; enjoy them while we have them and purchase a new one each year.

You can get answers to all your gardening questions by calling the Tulsa Master Gardeners Help Line at 918-746-3701, dropping by our Diagnostic Center at 4116 E. 15th St., or by emailing us at mg@tulsamastergardeners.org.

Garden tips

• Apply dormant oil for scale infested trees (crape myrtle bark scale) and shrubs when temperatures are above 40 degrees.

• If your roses have not been mulched, do so now. This is a good place to use those fall leaves which have been shredded with a mulching mower. Mulch not only will prevent cold damage to those plants which are susceptible but will prevent warming of soil on warm winter days which may promote premature cold sensitive new growth

Proper Mulching Around Trees

noreply@blogger.com (Ask A Master Gardener) — Sun, 24 Nov 2019 16:00:00 +0000

Avoid “Volcano” Mulch Around Trees

Brian Jervis: Ask A Master Gardener

Sunday, November 24, 2019

Q: As I drive around town, I see small trees and crape myrtles with very large mounds of mulch, kind of like a pyramid. Is that the right way to do it? VM

A: Master Gardeners call that a “volcano” of mulch and the No. 1 rule in the mulching handbook says, “just say no to the volcano.” More on the volcano later.

In reality, mulching your plants, trees, and shrubs (properly), is one of the best things you can do to contribute to their long-term success. Here’s why:

Mulch greatly diminishes the quantity of weeds. The protective barrier that mulch provides not only stops migrating weed seeds from making contact with the soil to take root, but also provides a barrier that diminishes the ability of emerging weeds to grow. Fewer weeds means more nutrients and water available for your plants. A good layer of mulch also reduces the time you need to spend on your knees pulling weeds.

Mulch helps regulate soil temperature. During the height of summer, exposed soil here in Oklahoma can vary by up to 40 degrees in a single day, with soil temperatures reaching almost 120 degrees at a 1” depth. When you use mulch, that daily temperature variant is reduced to only about 10 degrees. This provides a much healthier growing environment for your plants.

Mulch helps with water management. As you might imagine with the extreme soil temperatures of un-mulched soil, water management easily becomes a challenge. High soil temps cause the water to evaporate quickly. This increases the need for water, which directly corresponds to the amount of time you need to spend watering. In addition, more time watering typically equates to an increase in your monthly water bill.

Even in the winter, mulch can help retain moisture and protect your plants from cold winter extremes, decreasing the chances of those tender perennials freezing out.

There are a variety of mulch types you can use in your garden: wood chips, sawdust, straw, and even mulched leaves. As we are in the season where the leaves are falling or have already fallen, mulched leaves make a great garden mulch. You can run your leaves through a relatively inexpensive leaf mulcher or pile them in the driveway and let your lawn mower do the work.

After mulching, just bag them up, store them in an out-of-the-way place and next spring you will have your garden mulch ready to go. This also helps add organic matter back into the soil; something most every garden in NE Oklahoma will appreciate.

Now, back to the volcano. The main problem with mulch volcanos is that they are piled up around the trunk of the shrub or tree. As we have mentioned, mulch helps retain moisture and piling mulch against the trunks helps keep them moist, which contributes to disease and bark degradation … ultimately shortening the life of these plants. Mulching around trees and shrubs is great, just keep the mulch a few inches away from their trunks.

Remember, just say no to the mulch volcano!

Garden tips

· Apply dormant oil for scale infested trees and shrubs before temperatures fall below 40 degrees Fahrenheit. This would include crape myrtles infected with crape myrtle bark scale. Follow label directions.

· Continue to plant balled and burlapped trees.

· Wrap young, thin-barked trees with a commercial protective material to prevent southwest tree injury.