Living Green Roofs!

An Expensive Florida Living Wall's Death. Why?

noreply@blogger.com (Kevin Songer) — Fri, 03 Feb 2012 10:12:00 +0000

Florida boasts several wonderful Whole Food stores and I enjoy shopping within, relishing the samples of exotically delicious cheeses, thin sliced blood oranges and store-made salsa.

After yesterday's visit I chose a chair on the marketplace's front patio, affording me an opportunity to sit and think about why their beautiful and very expensive Florida Living Wall trellis system and plantings had miserably failed.

Whole Foods' dead Florida Living Wall

The living wall failure was nothing new. Ever since the store's construction and opening in 2008-2009 I had watched in fascination at the shiny stainless cabling and support brackets, hoping to see a lush, tropical wall of living, breathing vegetation established, one providing habitat for Florida's native anoles and tree frogs (themselves wonderful pest-management strategies), cleaning stormwater, fixing CO2, pumping fresh oxygen into the air, providing a much needed Sense of Place in an otherwise increasingly Urban Concrete Jungle and more.

However, despite the expensive trellising, cabling and other stainless attachement hardware, the wall supported little else but brown, dried and dead plants and vines.

Florida Living Walls must be designed with appropriate criteria to ensure survival

Such a shame because the trellising highlights the main entrance. Customers must walk past the dead vines and plants to enter the store. Though I am not a high-powered marketing expert I can easily recognize a sense of failure, brown and disappointment that most people would subconsciously acknowledge when walking past the dead vines and plants.

What went wrong? Who did the install and design?

Surely the trellis system was expensive enough and fabricated from a high quality material.

Why, after numerous attempts at plantings by staff and contractors are the living walls still dead?

Invasive Nandina is hiding the failed Florida Living Wall, Whole Foods, Jacksonville, Florida

These are all questions a good living wall designer must ask themselves long before final project specifications and ultimate installation.

Certainly the issue is not one of plants and constructed buildings being fundamentally unable to coexist. As we read in yesterday's post 'Green Roof Sleuthing' shows us just how compatible plants and structures actually are and in fact, buildings would soon be overgrown with plants if left unattended.

Some landscape designers I've talked to scratch their heads, wondering why the plants they typically specify and use in horizontal landscapes just dont work in Living Wall or Green Roof applications.

And there are many very important differences.

I've always said Living Walls are magnitudes times more difficult to design and successfully keep looking good in the long term.

So the designer needs to be on his or her game up front. All important design criteria must be analyzed and recognized when specifying all the components of a Florida Living Wall System.

As I rested on the front patio of the Whole Foods Marketplace in Jacksonville and examined the Living Wall design, the issues became obvious. The opportunity for a magnificent Florida Living Wall, one that would greet customers with lush texture, color and scents was there. Some of the components though were missing or ill-installed.

So what is the answer to the Whole Foods' dead Living Wall in Jacksonville?

Tomorrow's post will discuss what I perceive mut be done to produce the Florida Living Wall, one that would greet customers with lush texture, color and scents and truly welcome and invite money-spending clients inside.

Green Roof Plant Sleuthing! Understanding why some plants grow better on roofs.

noreply@blogger.com (Kevin Songer) — Thu, 02 Feb 2012 13:06:00 +0000

I call the process - 'Green Roof Plant Sleuthing'!

Simply put, Mother Nature is the best teacher for what grows well on a wall or on a roof in hot, dry, arid and monsoon-like climates.

Nature created green roofs cool buildings and provide habitat

When students of Green Roof technology ask me for recommendations concerning plants and green roofs, the first task I suggest is always to do a little Urban Sleuthing. Walk around downtown, watching your step and keeping an eye out for traffic yet looking up to the city roofs, gutters and tops of building structures.

Most are amazed to see just how many plants actually grow out of cracks, with minimal soil and survive the typical harsh conditions of a rooftop.

Green Roof Sleuthing is fun & educational!

Excitingly, these naturalized plants can produce a full and flush growth habit, offering an almost tropical look to the roof.

Walking through St. Augustine the other day I ran across many nature inspired green roofs, all quite beautiful and providing habitat, cleaning stormwater, cooling the buildings and pumping fresh oxygen back into the air.

Hidden among the lush resurrection fern were also many interesting smaller ferns, vines and other plant species.

MetroVerde finds many new Green Roof Plants through Florida Green Roof Sleuthing

So next time you wonder about the type of plants to use on your next green roof project, be sure to consult with your local nurseries and growers but also do not forget to do some Green Roof sleuthing yourself. Take a walk through the downtown and look up.

Chances are you may never use those plants you see growing out of the buildings but then again, knowledge is power, especially when working with plants on roofs!

Rain, Green Roofs in Florida and Climate Change Issues

noreply@blogger.com (Kevin Songer) — Fri, 27 Jan 2012 13:38:00 +0000

Drought everywhere! Jacksonville received only a small amount, way less than a tenth of an inch of rainfall last night.

MetroVerde Florida Green Roof, Breaking Ground

Here in Jacksonville we've had little if any rainfall for weeks now. The saying spring showers brings May flowers does not hold true for the geographic climate here. As weather fronts push down and across the US they loose momentum and dissipate just before reaching Jacksonville. All the dry weather is rough on green roof plants.

However, being situated on the Atlantic Ocean we are constantly exposed to high winds. When the weather fronts come through they drop all their moisture west of Jacksonville typically but retain enough wind turbulence to stress unprotected green roof plants.

Over the past year on the Breaking Ground Green Roof I have watched in amazement at the amount of water the dry winds were stealing from the plants as breezes whipped across the flat roof at 4 or 5 meters per second. Are we seeing the results of climate change or is this an expected cycle?

Of course the CAM plants were fine and this is why we suggest planting a belt of CAM plants around unprotected green roof perimeters. CAM plants generally keep their stomata closed during the day.

C4 plants like the Poaceae hold their own, as long as they are established. The corn, lemon grass and native grasses don't seem to mind the desiccating winds though I am sure after time they too would suffer without some rainfall. I love the wave action native grasses produce in the wind.

The Asteraceae too do well, again as long as they are established and again, most are considered C4 photosynthesis possessing plants.

But the C3 plants can dry out so quickly.

Because we are doing an install I water the plants to help them settle into their new home.

Typically, wind is so drying and strong I can hold the hose to where the stream of water was flowing vertically up and evaporating or being stolen by the wind before the droplets could ever make it back down to the plants.

Watching the C3 plant leaves move in the wind I could see the same occurrence happening, water being quickly vaporized out of the leaves just as the droplets from the hose where also 'gone with the wind'.

Sitting there with the hose I witnessed some of the more tender vegetables quickly wilt even with the hose water directed at their roots. The plants vascular system could not keep up with the wind induced evaporation of leaf moisture.

Without water in the leaves plants can not conduct photosynthesis. Without photosynthesis plants die,

Wind impacts are so significant across green roofs.

In MetroVerde's opinion wind exposure is, with light, availability the most important consideration for green roof design.

We've posted numerous articles here on how to use CAM plants as wind breaks. Understanding wind impacts on green roofs is critical for long term green roof design success.

Best Plants for Florida Green Roofs? There are many says MetroVerde!

noreply@blogger.com (Kevin Songer) — Thu, 26 Jan 2012 10:30:00 +0000

Best Florida Green Roof Plant?

Metroverde is always working to find suitable plants for Green Roofs in Florida. For years Northeast Florida has been experiencing a severe drought. Finding the toughest and most visually appealing is only part of the process. Habitat value, invasiveness, wind and drought tolerance are other issues we consider.

Green roofs in Florida are harsh places – remember the 7 (or more) H’s:

High Humidity
Hot, hot heat
High desiccating winds (killer)
Hurricanes (not the football team)
Hard Freezes
Horrible temperature swings
Hurtful droughts
Harmful floods

And we all are cautious about irrigating a green roof (I speak as a lawyer – not a botanist here) – our litigious society has already bred a number of legal articles on green building and tort. Imagine – the issues of:

Mold
Water damage to interiors
Collapse from weight (water is heavy)
Bacterial breeding
and who knows what else…

So if we choose to acknowledge Florida’s water shortage problem and build a green roof with micro-irrigation or no irrigation at all, then we need to look to plants that:

Can survive the many H’s
Are visually acceptable by the community
May be cost-effective
Are preferably native species (or non-invasive species)
Do not present a fire hazard or contribute too much dry leaf litter
Are low maintenance
Can survive long periods of drought
Can survive twenty inch downpours
Resist fungal infestations
and much more

Two of the most outstanding plants that almost begin to come close to the above requirements are:
1. Frog Fruit (Lippia nodiflora), and
2. Wild Garlic (Allium canadense)
I’ll be posting more data on these two species over the next couple days. In the meantime – what are your experiences with these species on green roofs?

Green Roof Plant Dwarfed 2 Year Old Allium Canadense

Florida Green Roofs and Wind Impacts on Green Roof Plants

noreply@blogger.com (Kevin Songer) — Thu, 19 Jan 2012 12:24:00 +0000

Wind is an oft-neglected but so important design parameter of green roof layout.

Dry, desiccating winds can damage or kill green roof plants faster then drought or a host of other environmental factors.

Included here are two photos of the same black-eye pea plants. One is on a wind protected green roof, the other is on a wind exposed green roof. Note the wind burn on the wind exposed roof plants.

Both looked the same prior to the 48 hour wind storm just leaving.

MetroVerde recorded between 10 and 20 Km/Hr winds on a continual basis for the 48 hours with almost non-existent water vapor or air humidity.

Florida Green Roof, Wind Protected Green Roof Plants

Florida Green Roof, Wind Exposed Green Roof Plants

Wind can burn or kill green roof plants quickly, taking an otherwise beautiful planting and turning into a brown mess within a matter of days. Even with more than adequate irrigation water applied - simply because the vascular system of the plants cannot keep up with the demand for water in the leaves.

CAM plants and those plants with stomata remaining closed or closing under lack of water conditions must be used as perimeter wind break plants on green roofs with out parapets or other wind protection if the green roof is not otherwise sheltered.

Understand the different types of photosynthesis green roof plants have. For a primer, check out the many articles we have posted before on CAM, C4 and C3 plants.

Other helpful sites are included here;

Great Irish Gardening blog article on wind damage in Ireland to garden plants.

North Carolina State University has another brief yet informative note on wind desiccation of plants.

Very interesting and informative Permaculture Wind Break Site.

Remember, your green roof site may receive plenty or precipitation or irrigation water, but if it is constantly exposed to desiccating winds the plants will experience the effects of wind damage.

Florida Green Roofs and a Terrible Drought! Looking to Poaceae

noreply@blogger.com (Kevin Songer) — Wed, 18 Jan 2012 08:09:00 +0000

Here in Northeast Florida we continue to suffer from extreme drought. Strange, because four hundred miles west lies the city of Pensacola with an abundance of rain. But here in Jacksonville, a harsh, dry, period of time marked with a significant lack of water is stressing and killing plants and contributing to wildfires.

Selecting those native plant species adapted to drought survival is important for green roof designers.

Poaceae is a good place to start.

Poaceae is the family of grasses, referred to previously as Graminaceae. According to Wikipedia, Poaceae contains about 600 genera and around 10,000 species of grasses.

Grasses comprise from 20-25% of all the herbaceous vegetation covering the earth.

Wikipedia, as other sources also suggest the Poaceae is the single most economically important family of plants in the world to humans, containing many food, grain and cereal crops, such as corn, rice, wheat and barley.

Poaceae grasses contain both C3 grasses and C4 grasses, referring to the much discussed in this blog 'photosynthesis process' type. The above link also contains a list of commonly known C4 plants.

C4 plants have evolved a process to survive drought. They protect compounds in their leaves, crucial to photosynthesis, from dessiccation and loss through a variety of means, including; timed stomata openings, storage of photosynthesis compounds in vacuoles and separation of photosynthesis reactions into differentiated cells.

This means they can make an excellent green roof plant or rooftop garden species.

As does corn.

Corn growing on Rooftop Garden, Sudan, photo by S. Newman

Sudan is dry. Corn, Periwinkle and Mango thrive. Photo by S. Newman.

As you can see from the above photos, Sudan is a dry and arid place, hostile to most plants.

However corn, a Poaceae family member thrives on a hot, dry, windy roof.

MetroVerde also grows corn on roofs, and the plants will grow well in places most others would wilt in a matter of days.

Other grasses too, members of the Poaceae family adapted to drought make excellent green roof plants. many are perennial and evergreen species, affording year in and year out color and texture, supporting biodiversity with food and communal shelter, providing beauty, cleaning stormwater and reducing heat island effect.

Purple muhly grass, Muhlenbergia capillaris, is another of my favorite green roof Poaceae.

Green Roof Muhly Grass, photo by C. Burkee.

Purple muhly gras, excellent C4 green roof grass.

There are many other grasses available and suitable for green roofs. Preferring to use native species, I consult with local nurseries in an area to see what they recommend for drought tolerance.

Your local native plant society is also a good resource for grasses recommendations.

The beauty of the Poaceae family is that they have been around a long time on this earth and survive in the most inhospitable of places.

Try Poaceae on your next green roof!

Green Roofs, Deciduous, Dormancy and the Color Brown

noreply@blogger.com (Kevin Songer) — Thu, 12 Jan 2012 11:29:00 +0000

Though not my favorite time of the year Winter always brings the welcomed sigh of relief to her pallet of colors with the appearance of a special deep brown. Anticipating next year's vigorous renewal, brown adds the fourth dimensional depth of time to the remaining sprays of green.

MetroVerde Green Roof Panel

Winter on the green roof is no different. In fact, winter on the green roof allows for a period of correction, recollection and hope.

Of course Winter here in Florida is mild compared to what others across the world experience with respect to duration, we still get cold enough here to induce dormancy and deciduous characteristics in many plant species (If you call a low seasonal temperature of the mid-20's F or - 6.5C cold).

Aptenia on a MetroVerde green roof

While it is always good to look out across a living roof and see vast expanses of green, deciduous brown can be reassuring.

Without the annual browning of the fast growing C3 plants the living roof would become a jungle, restricted in biomass output only by available water supply. However after the first hard freeze, dead biomass can be removed from the living roof to expose C4 and CAM plant type successes, successes to be built upon for subsequent years design and growth planning.

C3 and CAM plants across a sloped green roof in Florida

For living roofs in dry and arid climates experiencing sub-freeeaing winter temperatures, winter visualness can be designed to allow for striking contrast of textures and colors.

Catherine Burkee, Educational Director for Breaking Ground Contracting here in Jacksonville has a wonderful video and note of the Breaking Ground Green Roof she recently posted about the changes of seasons as seen on their living roof.

I am looking forward to a great 2012 for living roofs around the world!

Nature Designed Florida Green Wall & Living Roof Photos for Monday, December 12, 2011

noreply@blogger.com (Kevin Songer) — Mon, 12 Dec 2011 14:22:00 +0000

Enjoy these Monday Morning Volumetric Green, Living Walls & Green Roof Photos - most nature designed!

Volumetric Green, downtown St. Augustine

Look closely and you can identify many different plant species

St. Augustine, Florida Resurrection Fern

Resurrection Fern on the Roof

Living Wall, St. Augustine, Florida

Legumes atop a St. Augustine Stone Wall

Feral Sedum in the Rain Gutter

Florida Green Roof Allium

Aloe on the @BGGreen Roof

Bignonia Walls at the Jacksonville Zoo and Gardens

Green Roof and Leaves, Cation Exchange and Anti-Allelopathy Issues for Design Consideration

noreply@blogger.com (Kevin Songer) — Fri, 25 Nov 2011 09:12:00 +0000

I had a couple of comments yesterday about my post on Allelopathy and Green Roof design. As we focused on the potential negative impacts adjacent trees and their sap drip, leaves, seeds and shade can have on green roof plants we should also remember certain trees can bring distinct advantages to a green roof or nearby permaculture garden.

Leaves on the Green Roof can exert both Allelopathic and/or anti-Allelopathic influences

One comment suggested we should take into account the addition of organic matter from leaves, replacing lost or broken down compost.

Trees or adjacent shrubs that stimulate growth through their presence, leaf or sap drop or other factors are commonly referred to as possessing 'Anti-Allelopathic' properties. An anti-allelopath encourages nearby plant growth. Actually this is a big complicated name describing a common simple practice - composting.

Chinese tallow tree, Triadica sebifera, a terribly invasive species here in Florida and across tropical areas is rated as one of the best anti-Allelopaths, her leaves and sap encouraging adjacent plants to grow as though fertilizer has just been aded to their base.

Leaves can be very useful on the rooftop garden, green roof or in the ground level permaculture garden! Leaves cool the soil, promote soil moisture content, provide organic matter (good for bacterial breakdown of pollutants) and supply micronutrients, can adjust pH and cation exchange potential.

No leaves? May not be too glamorous yet very practical ( remember Louis Sullivan and functionalist architecture) collecting your neighbor's bagged up yard leaves can benefit your green roof or permaculture garden and benefit your wallet.

As mentioned, cation exchange capacity and pH are two important variables of a green roof. Additionally, leaf compost can add valuable trace minerals needed by the rooftop plants. Some trees, including certain maples containing high sugar content in their sap and leaves possess an extremely low pH, in the range of approximately 4.5 to 5.5. Other leaves such as white ash and popular may have quite high pH's, approaching 8.0 or above.

American sycamore leaves shown here can exert Allelopathic influences

Leaf compost typically contains twice the amount of trace minerals by weight as does horse manure.

Interestingly, leaves from different species of trees offer varying characteristics. While ash leaves are relative neutral in pH, some maple species leaves are documented to possess a pH of around 4.5.

Research also shows use of properly composted leaves greatly increases the cation exchange capacity of soils. One of the important functions needed in green roof soil media is cation exchange capacity.

Though varying opinions of organic compost value to green roofs exist throughout the industry, many believe organic material in the soil media is highly beneficial to green roof plants.

Massachusetts' state DEP has published an informative paper on the value of leaves for compost, including discussing issues and benefits, nitrogen to carbon ratios, composting processes and more. This information is helpful to those just starting composting or those interested in studying potential allelopathic or anti-allelopathic effects on their green roof, living wall or ground level permaculture bed.

Fossa alterna technology also relies heavily on leaf use and in turn has produced informative leaf nutrient information.

Remember, green roofs are individual ecosystems, intricate webs of life with complex interactions.

Flat roofs with poor drainage may or may not require lower organic content to prevent water saturation and facilitate drainage.

Sloped roofs may function appropriately with high organic content.

Again, if you lack adjacent anti-allelopathic trees then go out about the cityand find leaf waste destined for the landfill. Collecting heavy duty garbage bags filled with fresh raked leaves (we avoid those lawns heavily treated with fertilizers and herbicides/pesticides - those lawns are easy to spot here in the US due to the small advertising signs the lawn companies stick in the lawn after a fertilizer application - and speaking of lawns and fertilizers - a short must-see video of the history of the American Lawn will have you rolling in your chair and scratching your head at the same time can be viewed here) is a positive step for the environment.

Other benefits include;

Free highly effective cation exchange capacity supplements from the leaf compost
Free organic matter from the leaf compost
Free trace minerals from the leaf compost
Free pH adjustment material from the leaf compost (this is especially important when using higher pH soil media or media high in calcium)
Free garbage bags
And a lesson to your children riding with you to scavenge that recycling is more important than pride. :)

Green Roof Photos for a Florida Thanksgiving

noreply@blogger.com (Kevin Songer) — Thu, 24 Nov 2011 14:31:00 +0000

Happy Thanksgiving ya'll from the hot & dry deep south. Enjoy the fresh, just snapped Green Roof photos! Blessings to all.

Rooftop Permaculture - Fresh, Dew Kissed Greens on the Green Roof by MetroVerde

Pink Muhly still blooming in late November on the Green Roof by MetroVerde

Mint, Basil, Garlic & Clover on the MetroVerde GreenRoof

Autumns leaves decorate the MetroVerde Green Roof

MetroVerde Green Roof Lemongrass & Salad Greens

MetroVerde Green Roofs are shallow and lightweight

Living Roof on the front porch of a home in the Riverside Avondale Historic Preservation District

MetroVerde's green roofs are nature irrigated and use many native wildflowers

Mint and Allium on the MetroVerde Green Roof

Green Roof Plant Design - Useful and Harmful Effects of Allelopathy

noreply@blogger.com (Kevin Songer) — Wed, 23 Nov 2011 10:28:00 +0000

Plant matter such as bark, leaves, twigs, nuts and pollen can act as a herbicide, interfering with other plant's cell division, nutrient uptake, photosynthesis, et al. Some plants have strong effects on other plants, preventing growth in some and encouraging growth in others.

American Sycamore leaves are known for allelopathic properties (maybe they will surpress the Bidens alba!)

The University of Florida defines allelopathy as, "beneficial or harmful effects of one plant on another plant, both crop and weed species, by the release of chemicals from plant parts by leaching, root exudation, volatilization, residue decomposition and other processes in both natural and agricultural systems."

Plant matter such as bark, leaves, twigs, nuts and pollen can act as a herbicide, interfering with other plant's cell division, nutrient uptake, photosynthesis, et al.

An allelopathic tree usually exerts negative influence on adjacent vegetaion via a number of different processes, including;

Fog & dew drip
Leaf litter
Volatilization
Sap drip
Pollen
Other biological processes

Understanding allelopathy is especially important for green roofs and rooftop gardens with surrounding, adjacent taller trees. Allelopathy can greatly surpress rooftop food production.

According to the University of Georgia, School of Forestry Resources , there are a number of significant allelopathic trees requiring attention when planting other plants nearby. They include;

Strong Potential for Allelopathic Impacts
Acacia spp
Acer saccharum
Ailanthus altissima
Celtis laevigata
Celtis occidentalis
Eucalyptus camaldulensis
Eucalyptus globulus
Eucalyptus spp
Juglans cinerea
Juglans nigra
Leucaena spp
Myrica cerifera
Picea engelmannii
Platanus occidentalis
Populus deltoides
Prosopis juliflora
Prunus cornuta
Prunus serotina leaf
Quercus falcata leaf
Quercus marilandica
Quercus rubra
Quercus stellata
Robinia pseudoacacia
Sassafras albidum
Ulmus americana

Moderate Potential for Allelopathic Impacts
Abies amabilis
Abies balsamea
Abies grandis
Acer circinatum
Acer negundo
Acer platanoides
Acer pseudoplatanus
Acer saccharinum
Aesculus glabra
Aesculus hippocastanum
Aesculus octandra
Arbutus menziesii
Carya illinoensis
Carya ovate
Corylus spp
Crataegus spp
Fraxinus excelsior
Ginkgo biloba
Gleditsia triacanthos
Juniperus monosperma
Juniperus scopulorum
Kalmia spp
Picea spp
Pinus banksiana
Pinus contorta
Pinus densiflora
Pinus edulis
Pinus elliotii
Pinus monophylla
Pinus ponderosa
Pinus sylvestris
Prunus pumila
Quercus alba
Quercus borealis
Quercus douglasii
Quercus gambelii
Quercus michauxii
Quercus shumardii
Rhododendron maximum
Rhus copallina
Sorbus sitchensis
Tsuga canadensi

Slight Potential for Allelopathic Impacts
Abies concolor
Aesculus spp
Betula pendula
Carpinus spp
Casuarina spp
Cupressus macrocarpa
Fagus spp
Fraxinus spp
Larix decidua
Picea excelso
Pinus palustris
Pinus spp
Populus spp
Pseudotsuga menziesii
Quercus petraea
Quercus robur
Quercus rubra
Salix pellita
Sambucus racemosa
Sequoia sempervirens
Taxus brevifolia
Thuja plicata
Tilia americana
Tilia cordata
Tilia planifolia
Ulmus laevis
Ulmus parvifolia
Umbellularia californica

Adjacent to the Breaking Ground Green Roof (see photo above) there are American Sycamores, Platanus occidentalis located in the southeastern and southwestern corners of the living roof. The American Sycamore can produce significant allelopathic influence on adjacent green roof plants. Data exists showing the active ingredients, scopoletin and chlorogenic acid found in the Sycamore leaf may interfere with the ability of stomata on certain plant's leaves to function.

Interestingly, according to the University of Florida's IFAS publication referenced above, allelopathic properties can also be used strategically to control certain weeds, i.e. dried mango leaves surpress nutsedge tubers from sprouting.

Finally, good green roof design incorporates into design the potential and foreseeable effects of adjacent trees and other vegetation. Recognizing and dealing with a potential allelopathic problems during design can save months or years of not knowing why a green roof is barely surviving.

Know the basics of plant allelopathy is you intend to work in green roof design!

Fertilizing Green Roofs? Stop Now!

noreply@blogger.com (Kevin Songer) — Tue, 22 Nov 2011 23:39:00 +0000

Did you know your industrial fertilizers you are spreading across your rooftop garden contain Persistent Organic Pollutants (POPs)? Or are we denying the many silent environmental and health impacts of POPs.

Having read the article posted by @psustentavel on Twitter - click here for the article about Persistent Organic Pollutants - the imagery of 'inorganic chemical 'fertilizers across countless green roofs, the use of drinking water for irrigation - even backup irrigation - and the reckless abandon with which we use non-native species for landscapes, including those on rooftops, made me think - in our rush to install green roofs atop buildings, are we too creating a chronic issue someone else will have to pay for?

The value of green roofs is unquestionable. There is solid scientific data to back up claimed benefits of habitat creation, carbon sequestration, oxygen production. greenhouse gas reduction, heat island effect tempering, cleaning of stormwater, integrated pest management and so much more.

Florida Extensive Green Roof Nature Irrigated

There is no doubt about the value properly designed and maintained green roofs can bring to the Urban Core.

Green roofs can be used to support Urban Permaculture - small scale, individualized rooftop farming operations providing food, fiber and medicine to city residents.

And many urban areas around the world are moving ahead with plans to increase urban agriculture. Singapore, for example, produces 25% of the entire city's vegetable crop within the city limits. For a fascinating look at the importance of urban permaculture read foodsecurity.org's white paper entitled Urban Agriculture and Community Food Security in the United States; Farming From the City Center to the Urban Fringe.

Rooftops are the new frontier of real estate in many urban areas. Cities with limited available ground level real estate have acres of open rooftops.

Vegetated and green roofs are increasing in popularity, showing an impressive growth rate trend over the past decade. According to Greenroofs.com, public awareness of and interest in green roofs is steadily growing.

Yet in our noble rush to restore volumetric green to the urban core we hopefully will recognize the potential environmental costs associated with mass production of green roofs. The 'One Size Fits All' approach to green rooftops will not work for the worlds vastly different ecosystems. Sadly and reminiscent of mega-agriculture's damaging past practices, we as an industry turn to potent chemicals to fertilize, control pests and then use much needed drinking water to either irrigate or serve as backup irrigation.

Independent and craftsman-like green roof design and construction could disappear.

As with the POPs causing health issues in Pakistan and other places, our indiscriminate use of hardy invasive species, potentially toxic chemical fertilizers, pesticides and herbicides on green roofs is a Ponzi Scheme our children too will pay for.

Importantly, we as an industry have already moved far in the direction of ecologically inappropriate and environmentally dangerous green roof design. Florida's FDEP green roof in Pensacola, Florida possesses a large drip irrigation system, backed up with potable drinking water and planted with slow-release fertilizer compounds and soil amendments.

As in hidden environmental consequences associated with corporate profitability, denial of reality is the basis of success. Though the 'green' benefits of the FDEP green roof are often touted in the media - the fact that chemical fertilizers are applied and potentially damaging to Escambia Bay's ecosystem are hidden.

Yet FDEP is fully aware of the environmental problems resulting from POPs, fertilization and pesticide use on green roofs. In the proposed, new State of Florida Stormwater Applicant's Handbook, FDEP allows green roof credit for volume retention of stormwater only (no water quality credit), and recognizes fertilizers and pesticides will be used on green roofs (why no water quality credit is given), an approach we must reject. Moreover, FDEP is requiring the purchase and use of a 'pollution control media' made from ground up automobile tires under the green roof soil media to keep the fertilizer's nutrients on the roof.

Over time and as water evaporates, added pesticides, herbicides and fertilizers will concentrate back into the surface waters and become an issue for our children.

In the rush to add volumetric green to the Urban Core, the POP issue could easily go unnoticed.

Temper the hurry to install a green roof with the knowledge of a local native species botanist and a soils expert. Rather than ordering large amounts of hothouse pampered plant material, find a local nursery with individual plants acclimated to the climate.

Green roofs can be crafted to add artistic, educational, ecological and ethnobotanical value.

But we must first reject the incorrect notion that green roofs must be fertilized, irrigated with drinking water and doused in pesticides.

Green Roof Plants - What Makes Roots Happy?

noreply@blogger.com (Kevin Songer) — Tue, 22 Nov 2011 09:26:00 +0000

Removing older green roofs to allow for a new project has opened my eyes to the way green roof plant roots grow. Root growth science is also know as 'root architecture'.

As you can see, roots do not like to be constrained. Though all roofs have a perimeter and roots must eventually reach a boundary, allowing the plants to reach out for nutrients and water offers many benefits!

Tomato plant roots reaching out horizontally in the Green Roof hurricane weave

Having grown plants in pots for decades I can say with no uncertainty root bound plants are prone to disease and do not preform well in the long term.

Pot bound roots spiral around and around looking for room to grow

Green Roof trays must be large to prevent root binding patterns

Normal root architecture is best achieved by open growing systems on Green Roofs

To me, a photo is worth a thousand words and it is easy for me to see how roots want to stretch out. Of course we've discussed the many benefits of horizontal root architecture in previous posts. An example of a shallow green roof application can be found here.

Let your green roof roots grow. If you use a tray system make sure the trays allow for root crossover through adequate openings.

Roots need oxygen too. When roots grow too deep or are strangled by other roots due to a lack of horizontal growing room the plants can suffer. Providing adequate horizontal growing room ensures good plant development, unless you are using tap root plants (not too many of these are appropriate for green roofs).

Green Roof Plant Design - Heliotropoism, Diaheliotropoism and Paraheliotroposim

noreply@blogger.com (Kevin Songer) — Mon, 21 Nov 2011 23:55:00 +0000

Understanding photosynthesis processes in green roof plants is crucial to the green roof designer and we have discussed the difference between C3, C4 and CAM photosynthesis processes in prior notes, including;

Yet nature is complicated and does not limit herself in resisting environmental stressor conditions to just the above three types of photosynthesis processes.

Cowpeas and other plants for example possess the ability to adjust their leaves position to either increase or decrease the amount of leaf surface area receiving direct sunlight.

Under Intense Sunlight Leaves Fold to Prevent Desiccation

Under optimal Sunlight C3 Leaves Open Widely

Under Optimal Sunlight Conditions C3 Leaves Open Widely

Heliotropoism is the term used to describe a plant's actions when it orients leaves to receive more sunlight and thereby increasing photosynthesis capabilities, i.e. - more CO2 fixation.

Diaheliotropoism describes a plant whose leaves actually track the sun'd path, maximizing solar contact.

Paraheliotroposim denotes a plants actions similar to the above photographs. During parahelioproposim, plants may fold or move their leaves to either;

Minimize solar contact, or
Minimize total leaf surface area,

either way reducing water loss and preventing desiccation.

Though C3 plants such as the beans - and most other of the world's food plants except the grasses, maize, and sorghum - do not possess as complicated a multi-cellular Calvin Cycle as C4 plants and are more susceptible to drought, they - through Heliotropism biomechanisms they do possess their own unique desiccation prevention mechanisms.

Green Roof Removal - Exploring Underneath Seven Year old #GreenRoof

noreply@blogger.com (Kevin Songer) — Mon, 21 Nov 2011 12:09:00 +0000

We recently removed a living roof installed in 2005 over a sloped asphalt shingle roof here in Florida to accomodate a new project. Of course I was very interested to see how the underlying shingles had fared for approximately seven years under a heavily used green roof supporting rooftop permaculture (tomatoes, allium and more).

Not surprisingly, the asphalt shingles looked as new as the day the living roof was installed in 2005. Green roofs protect underlying roofs from ultraviolet rays and sun damage, effectively extending the roof life by years.

Green Roof plants removed in preparation for roof removal

Mat is lifted from the roof, exposing the roof barrier

Interesting root architecture, showing green roof plant root reach

Roof is sloped with 5/12 drop

Root barrier is in excellent condition

Asphalt shingles appear like new, well preserved under the green roof

Green Roofs help preserve underlying roofs, extending functional life by years!

Rooftop Gardens in New York - RAD video!

noreply@blogger.com (Kevin Songer) — Fri, 18 Nov 2011 19:50:00 +0000

New York Farm City from Petrina TV on Vimeo.

Living Walls, the work of Bob Chabot at the Jacksonville Zoo

noreply@blogger.com (Kevin Songer) — Fri, 18 Nov 2011 09:50:00 +0000

Jacksonville, though certainly not a 'green' city, has a core group of individuals who want to see plants fill a concrete and asphalt void.

Bob Chabot who serves as Director of Horticulture and Facilities for the Jacksonville Zoo, as well as President of Greenscape of Jacksonville and Vice-President for the Association of Zoological Horticulture and I took a tour of his zoo gardens yesterday, focusing on several upcoming projects we are both involved in, the Lasalle Street native plant bioswale and living walls for the USGBC's North Florida Resource Center in downtown Jacksonville.

Bob Chabot & very healthy, flourishing lemongrass, Cymbopogon flexuosus

Of course, it helps to have all the mammal compost you ever need to grow great plants, however the design, combination and selection of native plants, Florida Friendly Plants and plants from around the world make the Jacksonville Zoo a virtual ethnobotanical and horticultural library.

Living Walls, Jacksonville Zoo, Confederate Jasmine, Trachelosperum jasminoides

Living Walls, Jacksonville Zoo, Cross vine, Bignonia capreolata

Bignonia and Trachelosperum offer several great advantages for vertical urban greenscapes. They are both evergreen, non-invasive, provide habitat for wildlife, offer a stunning array of scents and visuality and importantly are drought tolerant.

We'll post updates on the various projects as they 'grow'. In the meanwhile, if ever in Jacksonville be sure to take the time and tour the Jacksonville Zoo and Gardens.

Green roofs and rainfall, nature's best irrigation

noreply@blogger.com (Kevin Songer) — Thu, 17 Nov 2011 11:35:00 +0000

Green Roofs love rain

Rain is always welcomed by Florida green roofs. Problem is for years now we haven't been receiving as much rain from the sky as we historically used to receive.

In fact, the Jacksonville and other areas of Florida and the Southeastern US, such as Houston and others are experiencing long term serious drought.

So when rain visits here, the green roof systems and plants must take advantage of every precious drop of water.

Last night we received about 15mm of rainfall, a little over one half inch. Since all of our green roof systems are shallow in depth, I was confident the plant roots had an opportunity to adsorb a good amount of water.

Curious though to just how much water some our potted plants received, I ventured out into the nursery and selected a plant potted up in a one gallon container and removed the plant, examining the rootball for moisture.

Green Roof plants, Florida's rainfall events do not allow for much water adsorption anymore

As the photo shows, the top ten to twenty millimeters was wet. Beyond fifty millimeters or so the roots were bone dry.

Horizontal roof architecture for green roofs has advantages, particularly if the green roof lies in the hot and dry climates of the world. Horizontal root architecture is discussed here.

So though shallow roofs may not be the answer for all green roof applications, they have established themselves as viable alternatives in hot and dry climates, providing lightweight potential, lower cost, beauty, habitat and stormwater attenuation.

Green Roof & Nature Photography Unparalleled - Ryan Ketterman

noreply@blogger.com (Kevin Songer) — Wed, 16 Nov 2011 02:56:00 +0000

I love nature photography, especially Ryan Ketterman's images. Captivating. Ryan is setting the standard for world class green roof and nature photography. Ryan was gracious to forward me green roof, desert and ocean photos. Today I am posting the green roof & beach shots. I'll push the desert shots later this week. Be sure to check out his website here! http://www.kettermanphotography.com/. . Ryan's cool time lapse photography clips can bee viewed here . http://vimeo.com/21849160 and http://vimeo.com/15382956

Enjoy! Contact Ryan next time you need a great nature photographer!

http://www.kettermanphotography.com/

Green Roofs & Frost - We had frost in Jacksonville last night!

noreply@blogger.com (Kevin Songer) — Sat, 12 Nov 2011 12:23:00 +0000

I think this climate change is kicking into high gear! I can't remember a frost this early in the season - especially along the Atlantic Ocean but we have on this morning.

Frost on my #green roof heirba buena this am

So with frost comes a host of new green roof issues here in Florida. Of course you can take the boring way out and just be happy with a dead roof for half of the year.

Or you can use those plants capable of surviving hard freezes and our torrent summers.

I prefer the later - year round green and color. Costs the same. Looks much better than brown mushy bah.

One of the issues we learned over the years centered around frost bacteria. Certain bacteria can cause premature frosts on a roof at higher temperatures and then others can depress frost formation until significantly lower temperatures are reached.

Sounds like cool information for a gren roof designer. So I'm cutting and pasting here an excerpt from a previous years Pseudomonas post (the thing about SnoMax is too cool!).

Green Roofs behave differently in the cold seasons here in Florida and the Southeastern U.S.. Because cold weather will be here soon, I am re-posting an article from two years ago (December 2008) about bacteria, green roof plants and frost. Enjoy!......... Also - Check out the follow-up Pseudomonas blog post here.

In general, plants used in exterior living walls appear to be more resilient to cold than those flat on the ground. Dismantling one of my oldest walls last night, I was amazed to see one of the cactus plants, Disocactus flagelliformis, not only survive the cold but thrive. Amazingly, most of the literature on the web specifies a minimum temperature of 50 degrees F and clearly warns against frost exposure. Last year we experienced several nights in the low twenties. However the cactus keeps on growing.

With my curiosity peaked, I researched frost, cold and plants on Google trying to sort through the thermodynamics of air movement, heat and cold transfer and the five different types of frost. It seems that as the ground layer of air cools, the warm air rises. So the vertical positioned plants on the wall could actually be several degrees warmer than those plants on the ground. There are several interesting stories of how orange grove owners use helicopters to keep warm air blown back down into orchards in California on occasional nights with freezing temperatures or where frost may become a threat.

Additionally and to my surprise I read where many plants on the ground support epiphytc bacteria growth of Pseudomonas bacteria, a gram negative bacteria that also acts as an ice nucelator. From the available literature it seems that the presence of ice-positive Pseudomonas can actually cause ice/frost to form on the plant surface. Frost damages the epithelial layer, in many instances killing the plant.

There is a ice-minus strain of Pseudomonas also, a mutant bacteria that also occurs naturally that does not possess the ice formation encouraging mechanism that its non-mutant sibling possesses.

Leave it to capitalism to go figure out how to profit on these two types of bacteria. SnoMax - made by Johnson Controls - see SnoMax's website, is a product made from the ice-plus variety and is used for making snow! On the other hand, FrostBan - see article - creates a crop resilient to frost. FrostBan was the subject of many GMO battles during the 1980's and early 1990's.

I don't have the testing equipment to see if my Disocactus cactus had the ice-minus Pseudomonas, or if the plant growing vertically with excellent air flow had just avoided the dispersal of common Pseudomonas.

But the fact that it survives the cold and continues to grow on the wall is another piece in the green roof and green wall plant database we are all developing.

Amazing stuff.

Friday's Residential #GreenRoof Photo - Genora's Nature Irrigated Living Roof

noreply@blogger.com (Kevin Songer) — Fri, 11 Nov 2011 11:21:00 +0000

Quaint and strikingly beautiful, Genora Crain-Orth's is shown here in the photo my daughter, Jincy took with her Ipod day before yesterday.

Genora's nature irrigated living roof with native plants

The roof is lightweight, actually less than 50mm soil media, irrigated only with available precipitation, dew and water vapor.

Native species were used including Yucca filamentosa and Helianthus debilis.

The bees and butterflies love the roof!

Looking good after a long hot summer.

Green Roof Plants - choosing between those plants that produce seed and those propagated vegetatively

noreply@blogger.com (Kevin Songer) — Thu, 10 Nov 2011 09:04:00 +0000

When choosing plants for green roofs one is always faced with a decision to specify those species with a tendency to bloom and flower then set seed, or on the other hand go with those plants who normally are propagated primarily by vegetated cuttings.

Green Roof plants setting seed in Jacksonville, Florida

Yet the decision is not a simple one and carries far reaching consequences. Arguments for and against highlight the many benefits and disadvantages for selecting either approach. I prefer to integrate in so many plants who reliably produce viable seed for the following reasons discussed below.

November seeds sprouting on a Florida Green Roof

Seed provide variability. Like a roll of the dice, the many combinations of predictable but also unpredictable color, patterns and texture always provide a surprise waiting once plants set seed and those seed germinate into a new generation. Because of inherent variability, seeds are generically difficult to remove from the open source system and patent. Plants propagated via cuttings or asexual reproduction are much easier to protect under intellectual property rights laws and remove from public domain. So by adding plants who reproduce by seed to your green roof design, you ensure for the time an ongoing, royalty-free plant source season after season.

Green Roof Salvia lyrata and green roof seeds sprouting

Longing for seasonal variability including color hue shifts, texture changes and other plant responses is a fundamental part of humankind's side by side relationship with the plant kingdom. Plants who do not rise and fall with nature's cycles seem almost 'plastic' to me. Granted I use these 'plastic' plants to create central design structure and they serve faithfully providing green and form month in and month out. But these structure plants are only a backbone. The skins are the many hundreds of species, genus and families of flowering ephemeral and persistent native wildflowers, grasses and food plants.

Once established, seed producing green roof plants are an economic & ecological benefit

Familiarity with the signs of plant growth teases the senses like aroma from fresh baked bread. The Salvia lyrata in the above photo for instance is preparing to cover certain areas of the green roof with her wonderful lavender spring flowers, one of the first sights across the roof as winter recedes.

Life is a complexity of changing interactions. Green roof designers can tap into the interest of nature's spectacular array of surprising variability by using lots of plants who seed and reseed.

Nature Irrigated Green Roofs - how much water do you need!

noreply@blogger.com (Kevin Songer) — Wed, 09 Nov 2011 12:20:00 +0000

Nature is amazing. It has not rained for several days here and though we did recently have a little rain we are still far below our normal. In fact Jacksonville is still classified as officially experiencing severe drought conditions.

National Weather Service Drought Index

Yet nature provides ample water, even in times of drought here in the form of water vapor. Good green roof design takes advantage of all sources of water, including morning dew.

Nature's irrigation - morning water vapor

I am constantly amazed at just how much water rests on the green roof plants some mornings.

As though an irrigation sprinkler has been turned on across the roof, opportunities exist for the plant designer to use those species capable of condensing (those with fine leaves, hairs or waxy surfaces) to capture the water then direct the droplets to the green roof planting media below.

Working with an international hotel chain to improve their landscape vegetation I was asked to diagnose why a large collection of very big planters were doing so poorly. A large roof overhang directly above prevented morning water vapor from reaching the plants. However, only a few feet over and out from under the overhang other planters looked lush.

Fog and morning dew can contribute an important source of nature supplied irrigation.

I make it a regular habit to walk green roofs early, middle of the day and late. Surprises abound always. This morning I was amazed at just how much water was on the plants. Who needs a sprinkler?

Green Roofs - many times the last line of defense for water quality

noreply@blogger.com (Kevin Songer) — Tue, 08 Nov 2011 12:33:00 +0000

Green and living roofs are so very important to our water quality, sometimes being the last line of defense for removing pollutants before runoff enters our waterways.

Green roofs slow down stormwater, cleaning and sequestering pollutants

Even small green roofs can provide a significant benefit to reducing peak runoff amounts and reducing loadings on creeks, rivers and ponds.

Blue Hole, Ichetucknee Springs

Once stormwater hits a roof and flows to the street below it may only be a matter of minutes before the water and any contaminants picked up as the volume flows across streets, drives and roads enters Florida's drinking water supply.

Floating wetlands, Gainesville, Florida - greenroof on a pond

Storm drain allows pollutants to enter waterways

Florida has a unique geology across many parts of the state called Karst. Karst formations are typified by limerock with caves, tunnels and holes throughout the formation. Once stormwater runoff enters the limerock above drinking aquifers the flow to the pools of underground water can be very quick.

Many times storm drains are a direct connect to water supply aquifers

Green roofs, living walls, floating wetlands and other best management practices can help keep water clean by slowing the runoff and removing contaminants from the water.

Wekiwa Springs, Florida - higher in nitrogen and algae

Wekiwa Springs, located just north of Orlando, Florida and shown above is surrounded by houses, streets, roads and commercial development. Though many good best management practices are in place to contain nutrients and runoff, the springs still suffer from high nutrient contents such as nitrogen and phosphorous.

Salt Springs, Ocala National Forest, not as impacted by development

Salt Springs in the Ocala National Forest on the other hand, though threatened by development, does not have all the septic tanks, stormwater runoff and as you can see, the water is much clearer, contains less nitrogen and other nutrients and is so much more healthy.

Installing a green roof on your commercial or residential building is just one small contribution you can make int he Urban Core to help protect water supplies.

Green Roofs and Rooftop Gardens can help defeat Urban Core hunger

noreply@blogger.com (Kevin Songer) — Wed, 02 Nov 2011 21:26:00 +0000

We can defeat hunger in the Urban Core - on the roofs, on balconies, in small yards and across patios! Food is so easy to grow in the harshest of places, with little of no soil and even when water supply is limited. All it takes is a basic understanding of the important factors impacting growth, such as wind, light and available water vapor.

Though permaculture has always addressed simple food growing principles, most of the time this focus has been about ground level growing.

Growing food on walls, roofs, buildings, and shacks up off the ground is important in the crowded urban core, high rises and slums. Ground level food production is many times impractical in cities because of the lack of open land. But there are plenty of walls and roofs to grow food on!

We believe educating the young about how to grow 'rooftop gardens is a way to capture their interest, create economic opportunity for them, create habitat, restore ecology and bring peace to the world.

Harvesting Green Roof Seeds, Educating the children

It is really exciting to see students become interested in urban agriculture.

Young children's minds are so fresh and thinking so quickly! They see opportunities to improve and enhance our green roofs, living walls and rooftop systems.

Offering the next generation hope through empowerment is what we need to be doing every day. Placing control of their food and water supply into our children's hands is so important.

Making educational videos about rooftop permaculture to teach the children.

It is a path to world peace and freedom from those who may want to try and control other's lives through food and water.

And growing food and recycling water does not have to be expensive or difficult. This is why education is so important.

But we have a fight ahead of us. Large corporations see opportunity through control of food, water, seeds and the knowledge of how to grow food and collect water.

The 'I don't have a green thumb and can not grow food' storyline is often repeated and many of the world have come to believe they can't grow sufficient supplies of food in the urban core.

We must show our children the path to breaking reliance from those who would control our lives and souls in exchange for food and water.

A small living wall or rooftop garden can provide enough seeds in a growing season to grow five more gardens the same size the following year. Seeds are free.

Systems can be designed to cheaply capture and store water and to grow food on even shacks made from rusty tin.

The students harvested a giant luffa sponge from the roof this week. Organic luffa sponges cost five dollars or more in the store. The enterprising young person growing luffa gourds across the roof of their inner-city barrio could earn hundreds of dollars each season.

Plants not only provide food but they provide security, shelter and medicine.

I love Lydia Cabrera's quote I use over and over, paraphrased "there are more spirits in the plants than in the sky".

Aloe growing out of walls and on roofs becomes the local doctor's office in many instances.

Low cost Barrio-type house with living walls, food roofs & water recycling

Structure walls made from wire with grapes abundantly growing provides fruit, sugar, vine and community opportunities.

Rooftop beans and peas can feed the masses, not only providing daily food but offering up the following years crop of seeds.

Reusing water and controlling flooding

Native wildflowers planted across window openings and on the roofs and walls bring in the pollinators, crucial for food production. One must have native wildflowers growing side by side with food plants.

Collectively we have found a way to travel to the moon, harvest the atom and talk across the globe.

But this awesome generation has forgotten how to feed themselves.

Now is the time to relearn. Now is the time to show our children how to break leashes and create freedom.

Give me one month and the seeds I can carry in my pocket, a few wiling youth from the urban core and the plants of medicine, food, fiber and economy will be growing across the landscape. It can be done in a desert or a wetland, hurricane or earthquake prone areas.
We've answered the critics who say it can't be done, designed systems withstanding cyclones, created highly productive food systems in 30mm of sand, implemented bee hives on roofs, built water storage systems for practically no cost and are working now on a rooftop chicken system.

Control of your food is the path to freedom and peace. Reliance on the corporations for food is the path to bondage.