Every third garden, it seems, has herbaceous peonies, but I could go from one end of my town to the other and never see a tree peony. (Wrong. I do know of one other planting, dating back to a hundred years or so.) The scarcity is due at least in part to some myths and prejudices tree peonies have picked up during their thousand plus years of cultivation.

Myth Busting

The first myth is in the name. Tree peonies are not trees. Yes, they are woody, but multi-stemmed and usually no more than a few feet high and wide. Eventually, a tree peony may reach six feet in height, but that could take decades — or more! And that’s hardly a tree; hardly even a large shrub. But it does highlight a possible prejudice against planting tree peonies — they are slow growing.

It’s a fact that tree peonies are pricey. Eighty-five dollars would not be considered expensive for a tree peony a mere foot high. And you don’t have to look hard at all to find plants selling for a few hundred dollars each. One reason for this cost is that tree peonies are usually propagated by being grafted upon roots of herbaceous peonies, and fifty percent success in grafting is considered acceptable. And no matter how a plant is propagated, it takes three or four years before it’s large enough to sell. Spectacular blossoms, of course, also figure into pricing.

Years ago when a local nursery was offering tree peonies in one gallon pots for only ten dollars each, I immediately snatched one up. At this price, slow growth would be tolerable. And I was curious as to just how slow they actually do grow — and how fast I could make one grow.

Rumor also has it that tree peonies are difficult to grow. They hail from the dry mountains of western Asia, so abhor “wet feet.” And whether or not the plants dislike being buffeted by wind, such conditions would surely and quickly fray the splashy blooms. I found an almost perfect location for my plant — the slightly raised bed that borders my terrace and is protected to the north by a brick wall.

Full Bloom Ahead

My plant bore three humongous, red blossoms the first spring after I planted it. And the plant grew. Those blossoms formed at the ends of shoots that were each about eighteen inches long, making me hopeful that slow growth was a myth. But here’s the rub: Those shoots die back to some degree each winter. Still, a foot or so survives. A foot or so of growth each year is not too slow, and the plants allegedly pick up speed with age.

My tree peony is now 25 years old. It blooms reliably each spring — now, in fact. It’s tallest shoots are almost four feet high but it still has a ways to go before I’d call it a full-bodied shrub. I’ll never call it a “tree.”

A few years after purchasing that first tree peony I planted another one, this one white and blossoming a few days after its red compatriot.

And after that I added yet another peony, this one of the so-called Itoh varieties, which are hybrids of tree and herbaceous peonies. Their stems die back each fall, but are sturdy enough to hold blossoms upright. The blossoms spread open after the show as that from herbaceous peonies is ending and then hold their own for a few weeks.

The particular one I planted is Bartzella, whose blossoms are a half a foot or more across and are crowded with luscious lemon yellow petals highlighted with orange flames at the center. This one also has a sweet scent, which my two early tree peonies do not. Peony scents, good or bad, don’t travel far.

Bartzella tree peony

A Long History

Tree peonies made their way from China to Japan in the 7th century, as medicinal plants, then again in the 17th century, this time as ornamental plants. Japanese breeders developed tree peonies that were quicker growing — initially, at least — than the Chinese hybrids, but lacked their fragrance and fully double blooms. In the last hundred years, American and European breeders got into the act, too, so that now there are hundreds and hundreds of varieties — many of which are available from specialty nurseries (Cricket Hill Garden, www.treepeony.com, for instance).

My bargain plant was evidently a Japanese hybrid. The blossoms lack (good) fragrance and the plant did not come with a name like “Honeydew from Heaven” or “Coiled Dragon in a Mist Grasping Purple Pearl.”

Although tree peonies like to bask in abundant sunlight, the blossoms last longer if shaded. In China, individual plants in bloom are temporarily shaded beneath paper umbrellas, an amenity my tree peony thus far lacks. Despite these deficiencies, each of my tree peonies, and the hybrid, is glorious in bloom, and a first step into the world of those “other peonies.”

Growing Down

Why are these trees so sad — even with pink or white blossoms cheering up their branches? But of course: they’re not really sad, they’re just weeping.

So why are these trees weeping, then, even if they are not sad?

They weep because they want to grow down. Instead of young stems reaching for the sky, as is the case with most trees, young stems of weeping trees toy only briefly with skyward growth before arching gracefully down towards the earth. Some plants begin to weep in earnest only after they get some age to them.

Weepy Beginnings

A weeping tree may have begun life as a chance seedling whose quirky arrangement of genes directs its stems to weep. Some such plants, although woody, could hardly be called trees. A weeping kind of goat willow, for example, makes a kind of billowing groundcover.

Weeping Atlas Cedar

Or, a weeping tree may have begun life with normal stature — until some cells in some branch of that tree underwent a slight mutation to a weeping habit. Perhaps the mutation was due to the effect of sunlight or temperature, perhaps the mutation was spontaneous. At any rate, all new stems and branches originating from those changed cells weep.

Now let’s make whole new plants from that weeping seedling or those weeping branches. If the weeping plant is one that roots easily from cuttings, you could just clip off a branch, stick it in the ground or some potting soil, and nurture it along. A cutting won’t do, however, if the plant is one of those weeping plants — like that weeping goat willow — that just creeps along the ground. What you really want is a weeping tree.

To create a weeping tree out of ground hugging weeper, or one that doesn’t root readily from cuttings, you graft a stem or bud from the weeping plant atop a length of trunk, typically five or six feet high, of some upright growing plant. As with any graft, success is possible only if the trunk section is closely related to the weeping stem piece. Your weeping cherry, for example, was created by grafting a stem from a weeping cherry atop a five or six foot trunk of some upright cherry. The graft juncture is usually obvious throughout the life of the tree.

Graft union of old weeping cherry

Change of Habit

Sometimes a branch of a weeping tree will all of a sudden start reaching skyward. (Talk about a wacky looking tree!) That stem could have arisen from a bud below where the graft was made. Or a branch mutation might have retained some nonweeping cells that occasionally express themselves in upright branches. In either case, just lop any nonweeping stems right back to its origin.

Even looking beyond the ubiquitous weeping cherries and crabapples, weeping trees are not all that rare. Japanese dogwood is a lovely tree whose white blossoms unfold after the leaves are fully out; the variety Elizabeth has somewhat weepy upper branches. A weeping form of Katsuratree presents a waterfall of bluish green leaves.

For a weeping evergreen, few are more graceful than Sargent hemlock. Or more odd than a weeping form of giant sequoia, whose leading stem pushes skyward in fits and starts, zigging and zagging and dipping along the way but always remaining clothed in a shaggy mane of droopy branches.

Weeping Giant Sequoia

Many yards benefit from some weeping tree, whether it’s a willow along a streambank, a weeping cherry lending grace and tranquility to a front lawn, or a weeping beech providing a hideaway for kids.

Weeping mulberry

The only caution with weeping trees is not to plant too many, which might be more than one — otherwise, the scene can look sad indeed.

Weeping cherry

Coddled Beginnings

Imagine that you hadn’t set foot outside all spring… better yet, that you had spent all spring in a warmed cave . . .  then tomorrow you went out and stayed there. At the very least, you would have to put your hands to your eyes for a while to shield them from the sun. And if the night was very cool — not unusual this time of year — well, you would shiver. Fresh air and sunlight are great for the constitution, but you would have to first acclimate yourself to them.

The same goes, even more so, for vegetable and flower transplants. Indoors, where they get their start, they are, after all, coddled. They know nothing of wind, which can shake them up and dry out their leaves by too quickly drawing water from the tiny openings in their leaves (“stomata”). Their tender cells know nothing about dealing with cool temperatures, or temperatures that swing 30 degrees Fahrenheit within 24 hours. Their leaves have yet to experience blazing sunlight.

Vegetable and flower transplants bought from a nursery would not necessarily fare any better. The more even temperatures and high humidity of a greenhouse does nothing to prepare them for drier air on the other side of the glass or plastic.

Toughen Up

What’s needed before setting transplants out in the ground is to have them undergo a process called “hardening off,” which gets these plants acclimated to increasing intensity of sunlight, gusts of wind, fluctuating and cooler temperatures, and soil moisture levels that might border on drought one day and a week later turn boggy.

I actually get this process started indoors by brushing my seedlings. I don’t mean any extended caresses; just running the back of my hand, a dowel, or one of those brushes for removing snow from windshields over their tops a couple of times per day. These caresses mimic, to some degree, the effects of wind.

Hardening off outdoors needs to be gradual. Trying to toughen up plants too severely too quickly could send them into shock. Annual flowers and vegetables might respond by flowering prematurely. Flowering ruins a vegetable like celery, putting the brakes on stalk production and making those that remain too coarse too eat (fresh, at least; they’re fine for soup). And you don’t want flowers on a marigold plant before it has become big and bushy, or its growth will be stunted. The same goes for broccoli buds.

So the thing to do is to find some cozy spot outdoors, a spot that is sheltered from wind and receives sun for only part of the day, or else dappled sun all day. Move your vegetable and flower plants outside to that location, and leave them there for about a week.

Watering needs special attention because, barring rain or overcast conditions, plants are going to dry out much faster outdoors than they did indoors. I keep my plants slightly on the dry side to make for tougher growth, and gets them used to a condition they may have to experience once they are on their own in the ground. Too much water stress, though, could cause shock and its attendant effects.

Also pay attention to the weather. If a night threatens to be very cool, bring the plants indoors. I do so if there is any doubt about the weather. One cold snap could snuff out weeks of care, especially tragic because I wouldn’t be able to replace seedlings such as my ‘Italian Sweet’ peppers, ‘Carmello’ tomatoes, and ‘Lemon Gem’ marigolds. Nurseries don’t offer transplants of these and many other unique varieties.

Ready for the Great Outdoors

After about a week, plants get moved to a more exposed location, one that takes just the edge off gusty winds and broiling sun. I continue to keep a close eye on watering and nighttime temperatures. A week at this second location and plants will be ready to be planted out at their permanent homes.

During the couple of weeks of hardening off, plant growth becomes slower and stockier. This is good; it shows that the plants are getting ready to face the world. Mother Nature can be fickle, though, so I stand ready to protect even these hardened off plants, once they are out in the garden, with overturned flowerpots or sheets if a late frost threatens.

Ideally, this gradual hardening off, along with further protection, if needed, eases seedlings’ transition to the garden so they hardly know they’ve been moved. Which is as it should be.

No Idle Gossip

You often hear talk about various plants being related to each other. There’s the sunny-faced members of the Daisy Family, for example, and the Pea Family, all with pods. Cole crops, such as cabbage, broccoli, and kale, are close kin, all in the same genus and species. What characteristics link these groups of plants as relatives?

Yes, goldenrod is in the Daisy Family!

Before you blurt out that all daisies have petal-rimmed flowers typified by sunflower and aster, picture the flowers of goldenrod, also a member of this family. And although all cole crops have waxy, bluish green leaves, just look how the plants vary in form. We eat the stalk of kohlrabi, the leaves of cabbage, and the flower buds of broccoli.

Sex is Important

As with human families, plant kinship is based mostly on sexuality; and the seat of plant sexuality is in the flowers. A lack of understanding of plant sexuality prior to the 17th century was reflected in older systems of classification. For example, the third century B.C. Greek philosopher Theophrastus grouped plants as herbs, undershrubs, shrubs, or trees. In the 18th century, Pierre Magnol assigned plants to one of 76 families based on roots, stems, flowers, and leaves. Simple enough, but is a maple tree really related to a palm tree? Or a tomato to a marigold?

Also in the 18th century, Rudolf Camerarius started to shake up the plant world, and beyond, by establishing sexuality in plants. That is, plants have female parts, with ovaries, from which develop fruits and seeds. And male parts, whose pollen fertilizes the female flower and begins the development of the fruits and seeds.

Later in that same century, Swedish naturalist Carl von Linnaeus used the work of Camerarius to lay the groundwork for present day classification of plants, basing it on plant sexuality, their flower morphologies. The very recognition of sexuality in plants caused quite a kerfuffle at the time, made more so by his calling the stamen a “groom” and the pistil a “bride” who consummate the marriage when the flower blooms. “He wrote that ‘the flowers’ themselves contribute nothing to germination, but only do service as bridal beds which the great Creator has so gloriously arranged, adorned with such noble bed curtains, and perfumed with so many soft scents that the bridegroom with his bride might there celebrate their nuptials with so much the great solemnity.” 

Back to cold science . . . Let broccoli or cabbage or mustard bear flowers, and you’ll see that all have four petals — an important characteristic of the Mustard Family. And daisies are linked more by the intricacies of the small florets that make up their heads than by the sunny heads themselves. If you look closely at goldenrod flowers, you’ll see why it also is part of the Daisy Family.

Linnaeus’s system included what he called “classes,” each determined by the number, proportion, and position of the stamens, the male flower parts. Classes were subdivided into “orders,” each based on the number, proportion, and position of the pistils, the female flower parts.

Although Linnaeus’s system was easy to use and gave all plants a convenient, binomial name, improvements were needed — and made. In the 18th century, Bernard Jussieu found shortcomings in Linnaeus’s system as he attempted to arrange in natural groupings plants at the Royal Gardens at Versailles. Why should male flower parts reflect a higher order of classification than female parts, anyway? So Bernard regrouped plants into more than a hundred orders which are now recognized as plant families.

All the older systems of classification were limited by their basis only on form and structure. As genetics and evolution became better understood in the 20th century, they were incorporated into the scheme of plant classification. Theories about plant relations continue to change with new knowledge about plant evolution and as new techniques, such as DNA fingerprinting, unravel the genetic makeup of plants.

Families Out in the Garden

All this family talk is not idle gossip. What’s the practical use of all this slicing and dicing to us gardeners? 

I like to know which plants are in the Nightshade Family because, aside from tomato, pepper, eggplant, and tomato, other kin poisonous plants like deadly nightshade, jimson weed, brugsmansia, and tobacco.

I like to know that my blueberries, lingonberries, mountain laurels, and rhododendrons are all in the Heath Family, a family most of whom demand very acidic soils.Also useful for me to know that legumes such as green beans, peas, and edamame are in the Pea Family, enriching the ground with nitrogen with the help of beneficial bacteria they harbor in their roots.

Plants in the same family are often attacked by the same pests. Club root fungi, for example, are as fond of cabbage as its kin, so the way to starve this pest out of the soil is to wait many years before again growing any of these plants where you last planted them. Late blight attacks tomato, potato, and, to a lesser degree, pepper, eggplant, and tomatillo. Celery worms feed on dill, parsley, carrot, and other members of the carrot family. And celery, of course.

Celery worm

Eastern Black Swallowtail

These traits common to families are why I practice crop rotation. It is admittedly less effective with mobile pests. That celery worm is the larval phase of the eastern black swallowtail butterfly which can, of course, flutter by to another bed. Then again, I don’t mind this pest for the pleasure of seeing the beautiful butterfly. And the caterpillars themself ain’t so bad looking either.

Knowing plant families coaxes me to peer more closely at flowers and marvel at their simplicity or intricacy.

I’m not going to ramble on and on in praise of the many health benefits of soybeans, their high quality protein, their healthful oil, and so on. Nor will I go on and on about how this plant, cultivated for thousands of years in Asia, has found its way into the manufacture of plastics and other hardgoods. Henry Ford was an early devotee of this plant, so much so that in the 1930s each Ford automobile ate up a bushel of soybeans in one form or another. I’ll also keep quiet about the gustatory alchemy that has been wrought on this bean to transform it into tofu and tempeh as well as ersatz meats, milk, and ice cream.

What I won’t do, though, is restrain my praise of the simplest form of soybean (edamame), the fresh green bean merely steamed or boiled for 10 minutes or so (soft but not olive green) and then popped out of its pod into your mouth. The flavor is delicious, nothing like the dry bean after boiling or other processing, but rather like a cross between a fresh lima bean and shelling pea. If you want one new vegetable to try in your garden this year, make soybean that vegetable.

The best soybeans for fresh eating are varieties developed for this use. A number of varieties are available. I have grown a few of them, and although I hoped that tasty sounding Butterbean would taste and bear the best, the variety named Shirofumi won out because of it slightly smaller stature, good yields, and slightly better flavor.

Also Simple to Grow

Soybeans are bushy, frost-tender plants that you grow just like bush green beans. I plant them around the date of the last killing frost in spring, around the middle of May here in Zone 5. By then, the ground has warmed enough for them to sprout and by the time they poke up through the ground temperatures will stay reliably balmy.

Make rows a couple of feet apart. I garden in beds, planting two rows about 20 inches apart down a bed. In either case, drop seeds three inches apart into furrows an inch deep.

Once you are smitten by the delectable taste of green soybeans and want to stretch the harvest season, do so by planting varieties that take different times to mature or by putting in a second planting about three weeks after the first one. Staggered planting times don’t work with all varieties, though, because some bear in response to the length of the day. Later plantings then don’t bear later, they just flower before the plants have grown large enough to make a large crop.

What About Flavor

I wrote that green soybeans taste something like a combination of peas and limas, and to plant them like green beans — and yet, soybeans are as easy, or easier, to grow than peas, limas, or green beans. Soybeans tolerate hot weather better than peas, which languish by July, and cool weather better than limas, which languish almost until July, or all summer around here sometimes. And Mexican bean beetles, which in some years devastate green beans, have little interest in soybeans.

Okay, even the rose has its thorns; so must the soybean. Soybean plants grow larger than bush green bean plants, so tend to flop over. I used to keep my plants upright, mostly to keep my beds neat and passable, by putting stakes around the edges of the beds, then letting the plants lean on one or two courses of string tied to the stakes. I don’t know if the plants have become less relaxed because of climate change or whether I’ve become less fastidious with them, but I know longer support them and they no longer seem unduly floppy.

I also must mention animals: Soybeans are a dessert to rabbits and deer. Last year a rabbit found its way into my garden through a hole in the fence; it made a bee line for the edamame plants. So if either rabbits can make their way into your garden, forget about growing soybeans — unless you want to grow them as a trap crop to keep either of these creatures from feeding on other plants. Which some people do. Seriously.

Harvest soybean pods when they are fully plump and still bright green. As with limas and some other beans, soybeans are not wholesome raw, so steam or boil them in their pods for about five minutes before eating — timing is not critical. Cooled pods gladly release their beans when gently squeezed between your fingers.

If you have the foresight to plant enough so that you harvest more than you can eat fresh, pack excess cooked pods into bags or some other containers, then into your freezer. We enjoy the harvest from a twenty foot long bed in summer and then all winter.

If delayed gratification sometimes seems to be too much a part of gardening, it does teach us to appreciate the means to an end as much as the end itself. Especially with planting trees. Your vision might call for a towering maple or spreading beech in a corner of your front yard, but you can do no more than plant one, care for it, and wait.

Not that full-sized trees cannot be — and sometimes are — moved for instant effect. Take enough earth along, keep it intact around the roots, and even a large tree hardly knows it’s been relocated. Such moves demand heavy, specialized equipment and plenty of money. Even then, though, a number of these trees die within a year of their move, or just sulk for many years.

Size Does Matter

We mortals are better off planting smaller trees — much, much smaller ones. In fact, if you’re talking about trees that you ordinarily buy from a nursery, smaller is usually better than larger. Financial considerations aside, research has shown that if the same species of large and small tree are planted under similar conditions, growth of the smaller tree often outstrips that of the larger one after a few years.

One reason for the better growth of smaller trees is because they suffer proportionately less loss of roots in transplanting. A larger tree needs a lot more water to recover from its move, and because it takes longer to reestablish itself, watering must be continued longer, often for a few years.

Nursery trees are commonly sold balled-and-burlapped (B & B), in pots, or bare root. B & B trees are dug from fields in spring, their roots and attached ball of soil then swathed in burlap. Although such trees typically lose well over 50 percent of their roots during digging, these trees survive transplanting well as long as their root balls remain intact, they are planted soon, preferably before growth begins, and their tops are not too large in proportion to the size of the roots.

Potted trees spend their whole youth in pots — at least they should. Advantages of potted trees are that they can be transplanted almost any time of year and with no loss of roots. Potting soils are porous and watered frequently at the nursery, so after being transplanted a potted tree needs diligent and regular watering until roots start to spread out into surrounding soil.

Nix any benefits a potted tree gets from having its whole root system moved intact if the tree is to big for its pot. Then the roots grow around and around inside the pot, and sometime after being planted out, the tree begins a slow decline as it strangles itself.

Height and healthy roots indicate that this tree is just the right size for its pot

Bare root trees are those that are dug up from the field while they are dormant, then have some water absorbent material such as wet sawdust packed around their roots. These plants can remain in storage as long as they remain dormant (leafless and not transpiring water), and can be shipped in good condition when needed. Because they can be easily and successfully shipped, they are often available in greater variety than potted or B & B trees.

Unpacking a shipment of bare root trees

Some nurseries buy in bare root trees and pot them up to be sold as such. You’ll know this is the case when almost all the soil falls away from the roots as you tip it out of the pot. No problem with this as long as you’re being charged a price for a bare root tree and as long as the tree is still leafless.

But How Small, or How Big?

You’re now ready to shop for a small tree, or at least one whose top is not too big for its roots. But how big is too big? You could just eyeball the plant and use your judgement. 

Specific standards for B & B trees have been spelled out by the American National Standards Institute (ANSI). Those ANSI standards are quite detailed, but a few examples can give you a feel for what to look for. Three measures help judge the quality of a nursery tree: trunk diameter 6 to 12 inches above the soil line, tree height, and root ball diameter. According to the standards, a tree whose root ball is 12” across should be no taller than 4’ or have a trunk caliper of no more than 3/4 of an inch. Corresponding measures for root balls 18 inches across are 7 feet and 1.5 inches.

With potted trees, look for a tree whose height is no more than 2 or 3 times the depth of its pot. Even better is to tip the plant out of its pot. What you should see is plenty of soil, with young white, pink, or tan root tips growing at the outer edge. Thick roots circling the bottom of the root ball are a no-no.

My choice in buying a tree is a bare root plant that is 4 to 5 feet tall. Planted carefully, mulched, and watered religiously for their first season (one gallon per square approximated spread of the roots), the tree will take off and grow with minimal care from then on.

A good bare root tree, nice roots and height

So rather than shopping for a tree with the tallest trunk, plant small and enjoy caring for your plant, watering it, pruning it, and watching it grow. As your little tree grows, frost, rain, and sun will lend a patina to the trunk and limbs; near the ground, creeping plants will lend a gentle embrace. There’s no way around it — time is needed to bring character to any tree.

I hope that I’ve caught you in time, before your seedlings have stretched out too long and too thin. That’s a problem this time of year. Tomato, zinnia, and broccoli plants — they’re all growing up on sunny windowsills. It’s the combination of a bit too much warmth and a bit too little light that causes that stretching.

The easiest way around this problem would be to just wait until the weather warmed up enough to sow seeds directly outside. There, abundant sunlight, cooler temperatures, and buffeting by wind would make sturdy, stocky seedlings. Of course, do this and you won’t eat your first broccoli bud until the end of June, and you’ll have to wait until early September to admire your first zinnia flower or bite into your first tomato.

So we’re back indoors. Turning down the heat, pulling window curtains way back, cutting down any trees that block light in a south-facing window — all this helps. But still, you can draw just so much light into a window of your house, and it doesn’t compare with outdoor light. And the more sun you let stream in, the hotter it gets.

A Brush With . . .

There is another way to make your indoor seedlings sturdier and that is to merely touch or shake them. No need to make this a full time job, because brushing them back and forth ten times each day is sufficient, doing all ten at once or spreading the brushing throughout the day. That’s for this time of year; there’s some evidence that twenty brushings a day may be needed in June.

That brush that you and I use in winter to whisk snow off our windshields can find meaningful existence during the growing season brushing seedlings. Run it lightly over the tops of your seedlings. Or use a horizontally held broom handle. Or the palm of your hand. 

For something different, shake the seedling flat instead of brushing the seedlings. Or blow air on them with a fan for, perhaps, thirty seconds each day.

Although stocky and sturdy growth helps seedlings better survive transplanting and adapt to outdoor conditions, we don’t necessarily want our plants to remain dwarfed once planted outside. Fortunately, the dwarfing effect of shaking, touching, or wind wears off within days after transplanting.

While brushing plants to make them stockier might seem woo-woo, there Is science to back it up. The movement causes a slight stress which, in turn, causes release of ethylene gas, Ethylene is a plant growth regulator which can slow stem growth. After all, other plants are more familiar in such responses. Buffeting by wind is partly responsible for the stockiness of trees growing on windswept cliffs.

The emphasis is, as I wrote in the previous paragraph, on “slight stress.” You don’t want to break stems. Brushing and time will make those once-fragile stems more resistant to damage. Give seedlings a few days of growth before they are able to tolerate any stress.

Too young to brush

Everybody’s Doing It

Touch response isn’t rare among plants. What do you think makes a pole bean or morning glory stem twine around a pole? They are responding to touching the poles. The same thing makes tendrils of peas and cucumbers cling to a chicken wire fence. A scientist who stroked a pea tendril for 5 minutes found that it remained curled for days, as if pining for a twig or piece of wire to hug. 

Venus fly trap is another plant that responds to touch, in this case with the sensitive hairs within its trap. The trap clamps shut, but remains so only if those hairs continue to be touched for a few minutes after the trap closes, indicating a live catch.

Venus flytrap

The so-called sensitive plant (Mimosa pudica) has an equally dramatic, but less intimidating, response to touch. Touch makes its leaves collapse all of a sudden. The response can be as quick as a tenth of a second, with the signal, an electrical one, coursing through the stems as fast as 2 feet per second.

Mimosa collapsing

Shaking and touching plants doesn’t only or always dwarf them. Caressed cucumbers or melons bear a greater proportion of female flowers than do plants that have not been caressed.

And shaking a plant for long periods each day can lead to increased growth, a technique that has been applied in Japanese greenhouses using vibration — even music! I wonder if this means that talking to plants would also affect their growth. If so, don’t talk too much to your seedlings until you know how they’ll react.

(For more about thigmotropism, as touch sensitivity is called, and other sensitivities of plants, see my book The Ever Curious Gardener: Using a Little Natural Science for a Much Better Garden.)

Let’s go back in time, say, four hundred years. You’re puttering around your garden, your walled garden — walled to keep out animals and unfriendly neighbors. Hmmmm, you think, why not plant a fruit tree in that strip of earth against that wall, perhaps a fruit that will also benefit from the extra warmth over there? May as well make the plant look nice and orderly, too.

And so originated espalier (ES-pal-yay): a plant, usually a fruit plant, usually trained to an orderly and two-dimensional form. The word is derived from the Old French aspau, meaning a prop, and most espaliers must, in fact, be propped up with stakes or wires. 

Although today we rarely build walls to fend off unfriendly animals or neighbors, an espalier still might warrant a place in the garden. Grow an espalier where  you want a formal effect, especially where space is limited, or grow a row of espaliers side by side so they meld together as a living fence. Nowadays, no need to back an espalier up against a wall and no need to restrict espalier only to fruiting plants.

Pear espaliers at St. Jean de Beauregard

Most espaliers need a wood, wire, or rigid metal framework for support and to make sure their stems are straight and at the desired angles. For an espalier growing against a wall, erect the framework about a foot away from the wall so that air can circulate behind stems. Rather than tie a stem directly to the framework, it may be more convenient to lash it to a bamboo cane that follows the desired direction of growth, then tie the cane to the framework. This lets you keep the stem straight, but growing a whatever angle you wish no matter what the layout of the frame.

A Perk: Delicious Fruit Also

Espalier is not a low-maintenance way to grow plants. It usually demands repeated pruning through the growing season, perhaps in winter also, to keep the plant within bounds and to maintain that orderly appearance.

Is it worth all this trouble, having to erect a trellis and then so frequently pinch and snip to keep the plant in shape? Well, besides the ornamental effect, the actual growing of the espalier is fun. A well-grown, fruiting espalier represents a happy commingling of art and science.

Asian pear espalier trained self-supporting en arcure

You apply this science artfully (or your art scientifically) by, for instance, maintaining a congenial balance between stem growth and fruiting, pulling stems upward for more stem growth, or downward for more fruiting. Cut notches where stems threaten to remain bare. Shortening branches in summer to keep growth neat and fruitful.

Where you want branching, shorten a young stem. How much you shorten influences the number and vigor of shoots that regrow, with more severe cuts leading to fewer, but more vigorous, shoots. Where a stem is growing in the wrong place, just cut it away completely.

Done well every branch on a well-grown espalier is clothed throughout its length with leaves and, for the edible espalier, fruits. Those fruits, bathed in sunlight and air, grow especially luscious, large, and full-colored. 

Many Variations

An espalier consists of one or more main stems, “leaders,” off which grow “branches” and, in some cases, “ribs.” Branches are temporary, and on the solely ornamental espalier, you just cut them back as frequently as is necessary to keep the plant orderly and handsome. Growing a fruiting espalier is trickier, though, because then you have to be careful that your repeated pruning doesn’t cause flowering and fruiting to suffer.

Oblique cordon espaliers in Great Britain

The simplest form of espalier is just a single stem, a “cordon.” Set eighteen inches apart in a row, vertical cordons are a way to cram many varieties of apple into a small area. A horizontal cordon can be a decorative and luscious border for a path or garden. The fruiting cordon is best suited to plants that bear fruits on short growths, called spurs, so that the cordon can be kept looking like a cordon, rather than like a porcupine.

Apple espalier at Giverny

To see how other forms might develop from a vertical cordon, imagine terminating that single stem to split it into two stems, which turn away from each other before growing vertically again. You now have a “U palmette.” Split those two vertical leaders of the U again and you have a “double-U palmette.”

All these forms have an inherent shortcoming: They are threatened by apical dominance, which is the tendency, on any plant, for strongest growth from buds and shoots that are spatially highest.

Various forms of espalier have been devised to be artistic even as they sidestep apical dominance. One popular form is the “fan,” in which the central stem terminates to split into two stems that angle upwards and outwards. Other designs purposely weaken the central leader by bending it around in a decorative curve, rather than allowing it to grow straight upward.

An Especially Easy Espalier

Red currant is easy to espalier as a simple T; I grew one to adorn the fence around my vegetable garden.

I began by cutting away all stems except a single upright one, which would become the trunk. I tied it to a stake as it grew to keep it straight. Once the stem grew a bit higher than the fence, I cut it back to that point and selected two side shoots to become horizontal leaders — the “arms” — growing in opposite directions.

I had two goals with the developing leader: To keep it growing from its tip, and to keep lower buds active. Toying with a leader’s orientation is the way I achieved these goals.

Currant trunk with 2 developing arms

I initially trained the two horizontal arms at an upward angle to keep growth stimulated — the more upward pointing, the more tip growth and the less branching. As the arms approach full length, I gradually lowered them to slow tip growth.

The basic procedure for training the red currant espalier can be adapted to other forms and plants with a few additional wrinkles.

Once the leader was full length, I shortened it each year, when dormant, to just about where growth began the previous season. But even before it was full-grown, its older parts needed strict pruning to control branch growth and so maintain the neat shape of the plant — all without any sacrifice of fruit yield or quality.

In the case of red currant, this pruning is straightforward. I just shortened all branches to about five inches just as the fruit is starting to color. In winter, I cut those shortened branches back further, to about two inches. Thisbuilds up short, fruiting growths right near the leaders. 

How pruning accomplishes this goal with other fruit plants depends on a plant’s fruiting habit. More on that after your espalier has finished its training period . . .

If you want to dive deeper into espalier, see my book, THE PRUNING BOOK http://www.leereich.com/books, in which I devote a whole chapter to the techniques.

“Topsoil” is one of the haziest terms used by gardeners — and by those who sell the stuff. After all, topsoil is nothing more than the top layer of soil.

And what’s so special about this layer of soil? Under natural conditions, topsoil is the most fertile portion of soil. In the forest each autumn, leaves fall on the surface of the ground, where they are digested by soil life to release nutrients and create soil organic matter. In meadows, including prairies, the topsoil each year is similarly enriched by the remains of old roots, leaves, and stems of flowers and grasses.

Lush meadow above ground, rich soil below ground

It’s no wonder that the feeder roots of plants — from magnificent maples to midget marigolds — choose to live and work in the topsoil! Here is where roots find a soft bed and a congenial mix of food, water, and air. Much of that congenial mix is the result of the diversity of friendly bacteria, fungi, and other micro- and macroorganisms that make their home there. The diversity of life in that layer of ground helps plants fight pests. It’s rich in nutrients, especially nitrogen.

But What is Topsoil?

Topsoil develops naturally, but it takes centuries, even millennia, to develop.

Native prairie in N. Dakota. (Rick-Bohn-USFWS-wiki-CC.)

Because natural topsoil is a limited resource, it is not what you necessarily get when you purchase “topsoil.”

When you purchase topsoil, you might get whatever soil happens to be in the upper layer of any piece of ground. That top layer may turn out to be what was left after the real topsoil was eroded or stripped away some time ago.

Soil profile showing real topsoil

Or, purchased topsoil might be a manufactured product. Not that there’s anything wrong with manufactured topsoil, which is made by mixing almost any soil with some organic material such as compost or leaf mold. It can be a good substitute for the real thing.

Because “topsoil” is so ill-defined, it pays to ask some questions before you have a mountain of it slid off a truck bed into your yard. Ask the seller whether the topsoil was mined or made. Ask how much organic matter the topsoil contains. For comparison, a rich natural topsoil has about 6 percent organic matter.

Ask whether the mineral fraction, i.e. ground up rock particles, of the topsoil is a clay, sand, or loam. For most purposes, loams, which are equitable mixes of sand, silt, and clay, are ideal. (Sand, silt, and clay are designations of the size ranges of minerals in the soil, the ranges being 2 to 0.05 mm, .05 to .002 mm, and less than .002 mm according to the USDA system.)

The very small particles of clay soils have very small spaces between the particles which cling to lots of capillary water. The result: clay soils hold plenty of water but not enough air, which roots need to breathe. Sandy soils have the opposite problem, the large particles have commensurately large spaces between them; these soils cling to little water but have plenty of air spaces. However, a clay soil that is aggregated, with its small, clay particles clumped to form larger units, provides the best of both worlds: Air between the aggregates and water clinging to the clay size particles within aggregates. Air and water, just what plants need to thrive. Organic matter, besides its other virtues, helps aggregate clay soils.

Water, air, and mineral particles in clay, aggregated clay, and sandy soil

Another question worth asking before you get a load of topsoil delivered is whether or not it has rocks in it. You might already have a rocky soil. What you want is soil, not rocks.

How about chemical residues. Especially topsoil that has been scraped from the surface of farmland might contain pesticide residues. The effects of some pesticides can linger for years. 

Do You Really Need It?

Also ask yourself a question: Why are you buying topsoil? If you’re buying it to enrich very poor soil in your vegetable or flower garden, don’t. Use pure compost instead, either home made or purchased, spread right on top of existing ground.

Perhaps you have a low area in your yard that you want to fill, then plant to lawn, vegetables, trees — anything, in fact. No need to fill that whole depression with topsoil. Instead, first fill the bulk of the space with some cheap dirt, preferably a loam or sand. Then top the whole area with a layer of topsoil a few inches deep.

Perhaps you need soil to build raised beds for your vegetables. Buy compost in this case? No! Compost is mostly organic matter which is mostly compounds of carbon, hydrogen, and oxygen, which decomposes to carbon dioxide and water. The compost will sink dramatically in its bed, requiring more of the same.

For a raised bed, I’d recommend any well-drained — that is, sandy or loamy soil — to fill the bed leaving enough head room for a topping of 2 or 3 inches of pure compost . Each year the bed will require just another inch or two of compost for fertility and all compost’s attendant physical and biological benefits.

Perhaps you’re thinking of buying topsoil for a new lawn. Here’s a perfect use for topsoil. Lawn grasses thrive in rich soils, making topsoil an ideal covering for the poor dirt left at most construction sites or where topsoil has been stripped away or is otherwise lacking. Any excavator worth his or her salt will strip off and pile up topsoil to spread back out after excavation is finished.

No matter where you use topsoil, always spread it on top of the ground, where it can do most good. Good topsoil is alive and breathing, but not if it’s buried within the bowels of the earth. And besides, some of the benefits of topsoil, such as helping rainfall and air percolate into the ground, come specifically from its being on the surface.

People often stare at me in disbelief if I suggest buying a certain plant from a nursery 2000 or 3000 miles away. Surely no plant could survive such a journey!

Not so. This time of year, UPS trucks and airplane holds are filled with plants on the move.

I prefer to buy my plants at local nurseries. But when I want a specific plant, such as a Hudson’s Golden Gem apple tree on G.11 dwarfing rootstock, I have to turn to mail order. (In this case, it would be from www.cumminsnursery.com.)

If shipped from reputable nurseries, mail-order plants thrive as well as plants purchased locally. That “if” is a big one. As with anything else offered for sale, quality costs. Beware of any nursery offering super-bargains or whose ads gush with horticultural hype.

I remember many years ago seeing a magazine ad for “A Miracle of Nature! Climbing Vine Peaches.” Rather than quote extensively ad bait such as “dazzling golden blooms” and “fruit by the bushel,” suffice it to say that I happen to know that this plant’s fruits might look like peaches, but are, in fact, practically tasteless. They are a kind of melon, nowadays sometimes billed as a vining mango.

And forget about any “IRON-CLAD GUARANTEE” from such nurseries. The nursery is able to offer and support this guarantee because, like others in its class, it banks on customers’ forgetting about such claims as soon as spring melts into summer.

A few rotten fruits don’t ruin this barrel of apples, though: many mail-order nurseries sell quality plants and also have strong guarantees. Just read between the lines of any nursery ad or catalog to determine if the nursery seems reputable, and do your own research about the plants.

But back to that “vine peach:” I did research some contemporary information on it and to me the descriptions were not sufficiently disparaging. It was said to be very fragrant — in a bowl, not your mouth — and good for pickles or preserves, but not for fresh eating. 

Bare Root or Potted

Mail-order plants are shipped either potted or bare root. “Bare root” sounds brutal, but plants do fine shipped this way if handled properly by the nursery and you. The nursery’s job is to dig the plants while they are leafless, except in the case of small evergreens, then keep them cool, with their roots swathed in moist peat, sawdust, shredded newspaper, or some other water-absorbent, spongy material.

Years ago I ordered and received a small, bare root Nanking cherry plant that arrived looking like a forlorn twig with a few dried roots that had been just tossed into a small, plastic bag. No wonder the plant was so cheap. No wonder it never grew.

When I receive a bare root plant, I unpack it soon after its arrival, checking that the roots are still moist, then plant post haste. If the roots seem at all dry, I’ll soak them in a bucket of water for a few hours before planting.

If I can’t plant immediately because the ground is frozen or too wet, I keep the plant cool and moist by putting it in my refrigerator, if it’s small enough, with its roots wrapped in plastic, or by temporarily planting it in a shallow hole on shady north side of my workshop. Or I could just re-wrap with its roots in the moist (moistened if not sufficiently moist) packing material in which it arrived and keep it somewhere cool, such as in my workshop, which is unheated.

Potted plants can go longer before being planted out in their permanent location — as long as the potting soil is kept moist. The nursery’s job, in this case, is to pack the plants to arrive at your doorstep with their stems undamaged and their soil intact. Some nurseries have really mastered the art of packing and shipping live plants. Opening a shipping box of their neatly nestled, happy plants gladdens any plant lover’s eyes.

Bigger Isn’t Necessarily Better

Whether ordering a bare root or potted plant — even if you are buying locally — don’t always opt for the largest plant. Large, bare root plants often suffer more in digging and transit than smaller ones. Large potted plants often have their roots cramped and twisted into undersize pots. I lift the plant out of its pot to check on the roots; I should see some at the outside edge of the root ball, but not ropes of them going around and around.

Root ball of good nursery plant

Growth of smaller plants often outstrip growth of larger ones after a few years because they establish more quickly. They also require less aftercare, mostly watering, often just the season of planting for the smaller plant versus years for a larger one. I consider the ideal size for a bare root tree is a trunk-to-be four or five feet high.

There’s something satisfying about walking into a local nursery on a balmy spring day, drinking in the bright colors, the smells, the riot of greenery and textures, then buying a plant. If a local nursery doesn’t have the particular plant or quality I want, I buy mail-order.