Wednesday, March 30, 2011

Green Roof Hurricane Season Arrives Soon

The 2011 Hurricane season starts in about sixty days or less, though I've recently seen tropical storms form in May.  Is your green roof ready?

The key to hurricane and cyclone preparedness for green roofs is making sure everything is permanently attached to the roof.  Under Florida Building Code requirements everything must be permanently attached to the structural roof.

Cyclone winds flowing across a flat roof create uplift like a vacuum and can pull shingles or other roofing material up into the air.  Roof accessories such as pipes, vents, skylights, green roofs, planters and HVAC units are also subject to the wind stresses and may become problematic.

Green roof hurricane preparedness involves several fairly simple and straightforward steps, including;

  • Make sure there are no loose objects on the green roof, such as pruning shears, hand trowels or other hand tools
  • Check to see if there are any dead plants or large pieces of fallen plant material and remove
  • Inspect the green roof system for integrity
    • If the green roof system is a tray system, make sure the trays and not damaged by UV degradation and ensure no loose edges are exposed
    • If the tray system is a mat system, check for loose mat edges
  • Review the underside decking in the attic for any water stains or other indicators or leaks
  • Check to make sure the underlying structure is holding its form and nto sagging fromt he weight of the green roof
  • Replace organic material and soil amendments as needed
  • Look for adjacent dead tree branches or limbs that could fall on the green roof and have removed
  • Make sure there are no mechanical system repair parts left on the roof from maintenance - you'd be surprised at what gets left on a roof - look for loose screws especially!
Well established green roof plants create turbulence across a roof surface, and may act to reduce uplift in some instances.



Cyclones are powerful forces to deal with and entering hurricane season with the green roof system in top shape is important!

Tuesday, March 29, 2011

Green Roofs and Biodiversity, Floristic Survey Breaking Ground Contracting Project, Jacksonville, Florida

The Breaking Ground Contracting project is a LEED registered project on track for Platinum certification. Always amazed with the recycling and sustainability efforts the project supports, my latest visit to the site allowed for collection of background flora data collection.

Understanding benefits of sustainability, including those of green roofs and living walls is part of the effort Breaking Ground Contracting is conducting with the 'Green' building project.  Over time, biodiversity data will be collected and published as part of ongoing research.

As part of a baseline floristic survey, pedestrian transects were conducted across the site in the spring of 2011, during construction.  Site visits were conducted in January, February and March.  The site is relatively small and generally covered with impervious surfaces such as asphalt and concrete.  Adjacent lots include a warehouse, a parts supplier store and Interstate-10.

Though surveys have been completed for wildlife and trees, the data below focuses on herbaceous material existing on the site.

Importantly, though most herbaceous plant species have leafed out and can be identified, continual assessment will proceed through the summer.  Ultimately we suspect the biodiversity of both wildlife and plants will significantly increase with the addition of the project's living walls and green roof.  Interestingly, site contains thirteen different plant families (herbaceous plants) with the Asteraceae family being represented by more species than any other family.  Araliaceae and Lamiaceae are both also represented by more than one species on-site.  There are at least a total of nineteen different herbaceous plant species onsite.

Analysis of the biodiversity data will be ongoing and updated regularly here for educational purposes.

The BGC Site floristic herbaceous survey indicated the presence of the following plants (not including trees):

Rubiaceae family
Galium hispidulum
Smilacaceae family
Smilax glauca
Asteraceae family
Senecio spp.
Bidens mitis
Solidago arguta
Eupatorium capillifolium
Taraxacum officinale
Geraniaceae family
Geranium carolinianum
Anacardiaceae family
Toxicodendron radicans
Lamiaceae family
Lamium amplexicaule
Stachys floridana
Caryophyllaceae family
Stellaria media
Violaceae family
Viola sororia
Araliaceae family
Centella asiatica
Hydrocotyle umbellata
Poaceae family
Paspalum laeve
Oxalidaceae family
Oxalis corniculata
Lauraceae family
Cinnamomum camphora
Phytolaccaceae family
Phytolacca americana


The photos below are representative of the herbaceous plants encountered onsite.

Smilax, Senecio, Toxicodendron, Geranium
Lamium, Senecio, Stellaria

Bidens, Viola
Bidens, Viola, Senecio

Stellaria
Stellaria, Centella

Stellaria
Stellaria, Senecio, Paspalum

Senecio, Solidago, Geranium

Senecio, Oxalis, Geranium, Paspalum


Cinnamomum, Galium, Stellaria
Eupatorium, Galium

Eupatorium, Solidago, Galium


Galium
Galium, Phytolacca
Hydrocotyle, Senecio, Paspalum, Galium, Stellaria

Oxalis
Stachys, Galium

Taraxacum

Monday, March 28, 2011

Living Roof on Storage Shed - Cost-Effective, Roof Frame Construction, Green Roof Florida

We have to store plenty of hay for the Urban Farm animals.  The chickens, rabbits, ducks and geese go through quite a bit of hay.

Our hay-bale storage shed is designed aerodynamically to survive high wind loadings.  The structure also provided a perfect opportunity for vertical food production, an opportunity for a lightweight green roof ideally growing some sort of food plant.

The final greenroof design is shown in the photograph here.
Florida Green Roof on Eco-shed - Frame


Rafters are made from electrical conduit, though next time bamboo - a much more sustainable material - will be used to replace the conduit.

Florida Green Roof on Eco-shed - Frame
Rather than using a roofing material like tin, the rafters are covered with farm fencing.  A tarp is strapped to the top of the farm fencing, acting as a waterproofing layer and partial support for the green roof soil and plants.  One of the interesting aspects of the tarp and the fencing is the ability of the tarp to form a small indentation in-between the fencing runs, allowing for water to collect during a rainfall event and acting as mini-storage reservoirs for the roof.

A layer of rough ground organic material such as small branches, bamboo pieces and other bulky material was added to the top of the tarp for drainage facilitation.

Lightweight, high-organic content green roof soil media completed the green roof layer preparation and the pre-sprouted cow-peas added as the final green roof touch.
Rooftop Permaculture Florida Green Roof, Lightweight

We will be posting updates as the peas grow.  Just after one day on the roof it seems like they've already grown several inches!

Florida design code has an interesting concept for tidal surge areas - breakaway systems.  Breakaway systems allow for attached items, such as lattice work to detach in wave action without causing structural damage.  The shed design is similar - though only with respect to natural, lightweight materials.  The palmetto fronds serving as the siding may blow off in a hurricane, but because the shed is made to pipe and fence I would suspect the structure would easily remain.

The same principle applies to the green roof plants.  We've video documented the anti-shear/lift turbulence green roof plants cause in a tropical storm - Tropical Storm Fay.  As cyclone winds whip across the green roof plants turbulence is generated, resulting in a pushing down as well as a pulling up motion, ultimately offsetting and allowing the well-rooted green roof plants to stay in place.

Ultimately, a strong cyclone could possibly flatten everything in its path.

But for cost-effective, inexpensive design, the above concept has provided us with what we believe will be vertical growing space for food, habitat and beauty.

Thursday, March 24, 2011

Green Roofs, Living Walls & Biodiversity

Honey Bee & Taraxacum, Breaking Ground Green Roof Project

Documenting increases in biodiversity through Green Roof and Living Wall should be a fundamental component of all vertical green projects, providing valuable data to help with understanding how wildlife, birds, insects, reptiles and plants adapt to the Urban Core.  Most Urban Core construction sites possess limited biodiversity with vast stretches of impervious areas, asphalt and concrete, roofs and parking lots.

But concrete has its cracks and gutters fill with leaves and other organic matter, creating a small yet vitally organic base from where the smallest native wildflower seed may lodge, germinate and grow.  Many see these native species growing at the bases of buildings, in sidewalks and across the parking lot and immediately think 'weeds'!

With temperatures much higher than grasslands, meadows, forests or other ecological habitats covered in plants, the asphalt jungle is an inhospitable place for any plants or wildlife and it is difficult just simply to survive.

Over time our field studies have shown those plants growing in the Urban Core, though reduced many times in population sizes and numbers, are critical to sustaining biodiversity in the city.

Documentation of site species makeup and density should be conducted and various stages prior to construction or renovation, including the addition of green roofs or living walls, through the construction process and each year following the project's completion.  Establishing background, impact and then restoration levels of biodiversity will provide a clear picture of just how effective the 'Green' project was in supporting and increasing Urban Core biodiversity.

This week I was onsite with my camera at the Breaking Ground Contracting project, documenting what plants, trees and wildlife were observable.  I began on the eastern side of the building and made my way around to the rear, the southerly side, stopped, squatted and readied my camera to photo-document a Taraxacum blooming in the middle of the construction material.

Catherine Burkee, the Education Direction for Breaking Ground Contracting, in her blog best describes what happened next;

"Honey bees are having their issues these days, and amidst all of the buzzabout honey bees, we were excited to see that pollinating is alive and well at Breaking Ground Contracting. As our green roof expert, Kevin Songer, was walking the property, he saw this lone yellow wildflower (Taraxacum) and he wandered over to take a photo. Much to his surprise, as he went to snap the shot, this little honey bee came out of the petals. It gives us great hope to know that our site is attracting honey bees which are required to pollinate many of the worlds crops! Including the veggies we will be growing on our roof in the months to come! For some information on these amazing insects and their importance to our planet, go to http://www.sciencedaily.com/videos/2007/0703-honeybee_decline.htm "

Importantly, a contracting firm such as Breaking Ground Contracting here in Jacksonville, recognizing the value of vertical green and committing themselves to sustainability is noteworthy.  As a leader not only in the community, but in the state of Florida for sustainable building, BGC is making a sustainability statement for today, tomorrow and the long-term future - one of our children desperately need.

We will post the results of the site bio-survey soon and update the project's biodiversity study over time.

All plants, no matter how small or insignificant appearing support life, providing oxygen, sequestering carbon dioxide, offering refuge for wildlife, making nectar for food and giving shade to help keep our world a little more habitable.  Weeds are not just another plant to spray with 'Roundup'.  Weeds are the real key to biodiversity!

Wednesday, March 23, 2011

Green Roof Design Model Continued - Breaking Ground Contracting

Recall we previously discussed the two primary design variables for the Breaking Ground Contracting Green and Living Roof project, those being;

  • Light availability, and
  • Wind Impacts.
Light and wind are the two most important design factors to consider when designing a green roof or living wall for hot and arid climates.

Without light, plants cannot complete the photosynthetic processes and will not survive.  Even slight consistent wind impacts can evaporate water from the green roof or living wall plant leaf so rapidly the plant's vascular system cannot keep up, resulting in desiccation and death.  Understanding light and wind levels are crucial to green roof design.

The Breaking Ground Contracting green roof planting area models light and wind as shown in the following illustration:
Light & Wind Model - Green Roof @ Breaking Ground Contracting

Moving into the secondary design principles we look first to adjacent vegetation determining potential plant or tree allelopathic influences on the green roof as illustrated in the following.
Light & Wind Model - Green Roof @ Breaking Ground Contracting


The Breaking Ground Contracting Green Roof is lined on the west, south and east sides by relatively mature trees, including the following genus';
  • Quercus laurifolia, Laurel Oak - northwestern corner and eastern side of green roof
  • Betula (River Birch) - eastern side of green roof
  • Platanus occidentalis, American sycamore - southeastern and southwestern corners of green roof
  • Triadica sebifera, Chinese tallow - western border of green roof
Again, Allelopathy is the little referenced yet extremely important green roof secondary design principle of the bio-chemical influences certain plants and trees have on other plants and in this instance - on green roof plants. The Breaking Ground Green Roof planting area is surrounded on three sides by tall trees. Some of these trees are deciduous and loose their leaves during the winter, others like the laurel oaks keep leaf cover most of the year.

An alleopathic tree usually exerts negative influence on adjacent vegetation via a number of different processes including;

  1. Fog & dew drip
  2. Leaf litter
  3. Volatilization 
  4. Sap drip
  5. Pollen, and
  6. Other biological processes
Looking at the individual adjacent trees, research data shows us;

  • Quercus laurifolia, Laurel oak - although literature suggests laurel oak does not possess allelopathic qualities, care should be given to potential impacts of pollen and flower litter. The laurel oak adjacent the northwest corner of the green roof has stained the white TPO and covered the roofing material with a layer of leaf and pollen litter. Though laurel oak may not exhibit direct allelopathic influence on the green roof plants, potential for covering the plants with litter exists. Continued site inspection will be required to confirm any impacts on the green roof plantings.
  • Triadica sebifera, Chinese tallow - one medium height tree exists adjacent the western border of the BGC green roof. Chinese tallow has been the subject of numerous allelopathic studies and research. Interestingly, research exists to support the theory of Chinese tallow leaf litter and fog drip may actually support germination and shoot growth on adjacent plants. In fact, Chinese tallow was shown to actually improve germination and growth rates in Little Bluestem, Schizachyrium
  • Importantly, the American Sycamores, Platanus occidentalis located in the southeastern and southwestern corners of the BGC green roof have the potential to exert significant negative influence over the green roof plants. As indicated in the above list, American sycamore produces strong allelopathic effects. 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 malfunction, interrupting the vital processes of photosynthesis and either stunting plant growth or killing the plant. Close observation will be required on the effects of the American sycamore on the entire green roof planting area and in particular, the southeast and southwest corner plantings. Pruning of sycamore limbs away from the green roof may be necessary.
  • Betula, river birch is not represented as allelopathic in the available research data.
Good green roof design incorporates the effects of adjacent trees and other vegetation and allelopathic effect possibilities. Recognizing and dealing with a potential allelopathic problem is much easier and more cost-effective up front. Know the basics of adjacent tree and plant allelopathism and how your green roof design integrates into a site with pre-existing trees.


Tuesday, March 22, 2011

Green Roofs and Florida Building Code, Florida Green Roofs

The Florida Building Commission 2011 Report to the Florida Legislature recommends energy credits for vegetated roofs.

For the full report click here.

The focus appears to be primarily addressing stormwater and does not necessarily acknowledge habitat or biodiversity concerns.  Energy savings are important yet biological functions should also be considered.   Possibly granting landscape credits on local levels is one answer to the more global focus on insulation.

Importantly, under Florida Building Code, anything on a roof here must be permanently attached.  This is due to hurricane and cyclone impacts and wind uplift.

The two sub-committee working session reports for the FBC's Green and Energy Efficient Roofs are available in pdf format here also;

Florida is a unique state with respect to green roofs.  We have what I call the 5 H's;
  • Hurricanes
  • High Humidity
  • Hard Freezes/Frosts
  • High Desiccating Winds
  • Heat Extremes
The interesting challenge for the green roof designer in Florida is that many of the above could possibly be issues green roof systems and green roof plants must deal with in any given day.

Sunday, March 20, 2011

Impact of Adjacent Allelopathic Trees and Anti-Allelopathism Potential on Green Roofs

Allelopathy is the little referenced yet extremely important green roof secondary design principle of the bio-chemical influences certain plants and trees have on other plants and in this instance - on green roof plants.  The Breaking Ground Green Roof planting area is surrounded on three sides by tall trees. Some of these trees are deciduous and loose their leaves during the winter, others like the laurel oaks keep leaf cover most of the year.


An alleopathic tree usually exerts negative influence on adjacent vegetation via a number of different processes including;
  • Fog & dew drip
  • Leaf litter
  • Volatilization 
  • Sap drip
  • Pollen
  • Other biological processes
Trees impacting the Breaking Ground Contracting green roof include;
  • Triadica sebifera, Chinese tallow - western border of green roof
  • Quercus laurifolia, Laurel Oak - northwestern corner and eastern side of green roof
  • Platanus occidentalis, American sycamore - southeastern and southwestern corners of green roof

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

As mentioned, the BReaking Ground Contracting Green Roof will be adjoined by Chinese tallow trees, Laurel Oaks and American Sycamores.

Quercus laurifolia, Laurel oak - although literature suggests laurel oak does not possess allelopathic qualities, care should be given to potential impacts of pollen and flower litter.  The laurel oak adjacent the northwest corner of the green roof has stained the white TPO and covered the roofing material with a layer of leaf and pollen litter.  Though laurel oak may not exhibit direct allelopathic influence on the green roof plants, potential for covering the plants with litter exists.  Continued site inspection will be required to confirm any impacts on the green roof plantings.

Triadica sebifera, Chinese tallow - one medium height tree exists adjacent the western border of the BGC green roof.  Chinese tallow has been the subject of numerous allelopathic studies and research.  Interestingly, research exists to support the theory of Chinese tallow leaf litter and fog drip may actually support germination and shoot growth on adjacent plants.  In fact, Chinese tallow was shown to actually improve germination and growth rates in Little Bluestem, Schizachyrium


Importantly, the American Sycamores, Platanus occidentalis located in the southeastern and southwestern corners of the BGC green roof have the potential to exert significant negative influence over the green roof plants.   As indicated in the above list, American sycamore produces strong allelopathic effects.  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 malfunction,  interrupting the vital processes of photosynthesis and either stunting plant growth or killing the plant.  Close observation will be required on the effects of the American sycamore on the entire green roof planting area and in particular, the southeast and southwest corner plantings.  Pruning of sycamore limbs away from the green roof may be necessary.


Finally, good green roof design incorporates the effects of adjacent trees and other vegetation and allelopathic effect possibilities.  Recognizing and dealing with a potential allelopathic problem is much easier and more cost-effective up front.  Know the basics of adjacent tree and plant allelopathism and how your green roof design integrates into a site with pre-existing trees.


One of the related positive issues of anti-allelopathism and green roof adjacent trees is a benefit derived from leaf micro-nutrient content.  Tomorrow's topic will explore the antithesis of allelopathic impacts and look at the potential biological and chemical benefits from adjacent trees.



Friday, March 18, 2011

Green Roofs & Invasive Plants - Wisteria, Wisteria sinensis


Botanical name : Wisteria sinensis
Wisteria
Family/Famille : Fabaceae
We have spoken about invasive plants and green roofs here in these posts before. 
The most recent discussion centered around Nandia, Nandina domestica and the Gainesville Regional Utilities Greenroof project. Fortunately, with the help of the Florida Wildflower Foundation the Nandina was removed from the planting schedule.
Yet another beautiful but invasive plant species green roof designers should be aware of is the very hardy and drought tolerant Wisteria.
Wisteria sinensis

Wisteria or Wisteria sinensis is listed by the Florida Exotic Pest Plant Council as a Category 2 plant.

I am the first to admit the attractiveness and scent from wisteria is almost too alluring to resist. However I have also seen first hand the damage the plant can do as it is practically choking to death many of the large sweetgum trees on our Urban Farm. One part of me says - it is worth the color and beauty but then common sense kicks in and I realize we must take care with the plants we use in our landscapes and especially on our green roofs.


There are many alternatives for green roof plant use including both native species and landscape friendly species - species not native to an area yet also not considered invasive.
As mentioned in the post:

"The Florida Friendly Landscape program, an effort of the University of Florida and Florida's Water Management Districts, offers a concise and effective website for designing with ecologically friendly water conservation and ecological concerns.  Moreover, the website offers an interactive online design program to assist in selecting eco-friendly landscape plants.

Additionally, the Florida Native Plant Society offers many resources focused on preserving native ecosystems and plant communities.  Their Education and Outreach webpage makes available an example list of public gardens and natural areas using native plants for landscaping."


Ultimately, green roof design must be approached with consideration for many factors most of us do not consider, such as;

  • Native or exotic invasive qualities
  • Drought resistance
  • Wildlife value
  • Fire fuel contributor (high volatile oil content - remember how dry xmas trees burn!)
  • the 5 H's and much more.
Green roofs are a popular trend within the green building industry today.  The offer important benefits including;
  • Cleaning of nutrients from stormwater runoff (if the roof and stock plants are non-fertilized)
  • Providing much needed vertical green habitat to Urban Core wildlife (such as the green Florida anole - which in turn provides superb integrated pest management)
  • Creating beauty for people
  • Sequestering Carbon and CO2 and providing fresh oxygen as a result of photosynthesis, and more.
We must though, be aware of how we embrace green roofs.  We must take into account all issues, especially those with potential impacts on our ecology and environment. Selecting green roof plant species if a good place to start in designing a Florida Green Roof.

Thursday, March 17, 2011

Green Roofs at Apopka High Career Day - Amazing Ideas from Students

MetroVerde participated in the first annual Apopka, Florida High School Career day with four interactive hour long sessions.

I was quite impressed with Apopka High School's facilities and staff.  ROTC members escorted us guest speakers to our respective rooms.  The school was clean, bright and full of talkative young people.   Ms. Erin Poppert, the Science teacher who was responsible for supervising the Green Roof session ensured I had all the proper audio visual tools needed and participated in each of the four sessions.

Apopka High School
Apopka High School Career Day, Green Roofs

We talked about what green or living roofs were and touched on their benefits;

  • possible insulation qualities
  • habitat and support for biodiversity
  • food production
  • stormwater cleansing
  • integrated pest management
  • beauty - sense of place
  • production of oxygen and sequestration of carbon
  • and more
Reviewing the 5 H's of Florida Green Roof design principles - 
  1. Hurricanes
  2. Heat
  3. Humidity
  4. Hard Freezes
  5. High Winds
I could see students - the future scientists, engineers, botanists and entrepreneurs' eyes widen, thinking about the possibilities for economics, environment, health and opportunity.

We discussed rooftop permaculture at length and because we are actively involved in a rooftop permaculture project I thought it would be insightful and useful to solicit their ideas as to what vegetables would be good to grow on a roof.  I know the vegetables I like to use, and know what is drought tolerant and technically feasible to grow.  Sometimes however I find myself caught up in the technical and artistic components of a living roof to the point where I miss the human taste differences issue.

I wanted to find out in a broad, general sense what vegetables the young adults would prefer to grow on a green roof's garden.

  • Tomatoes - usually the very first response - most everyone wanted tomatoes!
  • Potatoes
  • Onions
  • Green beans
  • Strawberries
  • Cucumbers
  • Cabbage
  • Broccoli
  • Carrots
  • Lettuce
  • Celery
  • Peanuts - a very good suggestion (adding peanuts could produce fuel!)
  • Blueberries
  • Squash - calabasa
  • Grapes
  • Pumpkins
  • Eggplant
  • Watermelon
  • Peppers
  • Raspberries
  • Bananas
  • Oranges
  • Basil
  • Rosemary
  • Radishes
  • Turnips
  • Kiwi
  • Pineapple
  • Corn
  • Greens
  • Soy beans
  • Pinto beans
Interesting!

I will look over the list and learn from it, for understanding people's tastes is an important facet of rooftop permaculture.  Now all the above plants may not work on a green roof.  Many have varying soil requirements and other horticultural needs.  But a comprehensive list of desired vegetables from a broad cross-section of a geographic population is important data.  Understanding the people component to green roofs adds to the potential for long term success.

The Apopka High School day was much fun and I enjoyed the opportunity to interact with creative minds.

Ms. Poppert has fashioned a great science agenda for her students.

I suspect there will be some important future green roof and horticulture research develop as a result of the students inquisitiveness and Erin's efforts.

Tuesday, March 15, 2011

Florida Biodiversity & Permaculture Green Roof Project - Getting Started, Breaking Ground Contracting

The Green Roof for the Breaking Ground Contracting project in Jacksonville has begun!

Today the roofing contractor will be finishing the edges of the TPO.  Once the edges are sealed and the gutters up the drainage stabilization mat will be attached to the TPO.

The TPO is 80 mil and has a 2" drainage slope from the center towards the east and west edges.

Roof level view of BGC Green Roof Pad


The Breaking Ground Contracting green roof will support rooftop permaculture, native wildflowers and grasses and other endemic species and Florida Friendly Landscaping (drought tolerant) plants.

BGC Walkway to Green Roof, Solar & HVAC to left


Recall wind and light are the two most significant green roof design variables.  We call them primary design variables.  The wind and light summary chart is as follows.

MV GreenRoof Primary Design Variable Chart


Following the design principles we've been discussing here, the wind exposure is primarily from the south.  The following roof grid summarizes wind and light exposure.

BGC Green Roof Primary Design Schematic - Wind & Light Impacts

A green roof and rooftop permaculture mission statement is in development progress and plant layout proceeding based on design parameters.  Follow us as we proceed through the rood assessment into design and then installation.

Feel free to email us with your questions and we are always happy to receive comments.




Monday, March 14, 2011

Green Roofs and Permaculture

Growing food on rooftops is popular in many urban areas.  New York may be leading the way, especially with projects like the Eagle Street Rooftop Farm.

We are working on a Jacksonville, Florida green roof with a significant rooftop permaculture component this spring.

Vegetables are already seeded and many sprouting.  The Dinosaur Kale is about sixteen inches tall and the rocket arugula is growing well also.

We chose the roof area with the most morning sun and afternoon shade for the garden area as roof temperatures climb rapidly during the afternoon.  Though many vegetables, such as the Brassicaceae are considered C4 photosynthesis processing plants and drought tolerant, morning sun and afternoon shade is best.

Here back in the green roof plant nursery we have recently adopted farm fowl on our urban one acre lot.  With several chickens, ducks, geese and a turkey we've had to build enclosures to keep the neighborhood cats, raccoons and hawks from eating our birds.

This weekend we successfully constructed the $50.00 turkey enclosure.  At 200 SF the price per square foot calculates to be approximately twenty five cents per SF - not bad!

Green Roof Turkey House


The turkey castle is roofed with lemongrass, spinach, borage, onions, parsley, cucumbers, cantaloupe and cow peas.

The enclosure is made with simple farm posts, bent electrical conduit and wildlife - bird netting.

The soil media for the green roof is a very lightweight mix of perlite, vermiculite, sand and compost (compost about 50%).  We'll keep the roof fertilized with turkey pellets.

Green Roofs and Permaculture
And as our turkey appears to be a good flyer - I suspect he will be roosting often with the veggies.

Integrating vegetables, fruit and other items such as honey not only provides food for people but also habitat for wildlife.  Increasing the plants insects need increases biodiversity.  Pollinators are an important component of urban core gardening.

Rooftop permaculture - the new frontier for green roofs!

Friday, March 11, 2011

Green Roof & Rooftop permaculture - Economic Opportunity for the Urban Core

One of the components of the new Breaking Ground Contracting green roof will be a working permaculture garden.

Today we will be planting 10,000 yellow onions and garlic cloves for the project.  The cloves and onion sets are already sprouting so within a week the plants should be nice and green for end of month installation.

Garlic cloves for the BGC Green Roof Permaculture Garden & Green Roof

I was peeling apart heads of garlic until midnight last night.  Good time for green roof planting now due to the new moon.

Thursday, March 10, 2011

Learning about Native Plants for Living Walls & Green Roofs

Native plants play an important role in supporting worldwide biodiversity heritage.

For a great blog post on just how important native plants are for supporting biodiversity, read the post here at Wildlife Garden.

One of the many ways to learn about native plants is to 'look up'.  This week I spent several hours walking in the moat of the old Spanish Fort in St. Augustine.  In my opinion the National Park Service has it backwards - they charge for going inside the fort but allow you to walk for free in the moat and around the grounds.  The moat is where you can see many, many native and other plants species growing in the coquina walls!

Castillo de San Marco, St. Augustine

As you can see in the above photo, most plants grow underneath the downspouts on the walls.  Though the downspouts provide water primarily when it rains, they also collect dew and fog from surrounding areas and funnel the water to the plants.

Interestingly, learning about green roof and living walls plants from the fort offers insight into those plants that not only do well under the hot Florida sun and with no additional irrigation, but also the plants shed light on soil media composition.

Coquina shell and the limestome mortar have a quite high pH level.  High pH is usually one of the toughest issues to work with on green roofs and living walls.

Samolus valerandi
Pteris vittata & 2 Cuban anoles
Wildlife seeks out plants, especially those providing resource benefit such as food or nectar or shelter.  Native plants are best suited at providing the most optimum level of ecological benefit to those wildlife endemic to an area.

In otherwords, planting native plants on green roofs and living walls encourages and supports native populations of insects, birds, reptiles, amphibians and other wildlife.

Many popular landscape plants used on green roofs may not offer the same level of resource benefit.

Learning about your local native plants broadens design capabilities for both green roofs and living walls.

Limestone & Coquina Walls are Harsh Ecosystems

Tuesday, March 8, 2011

Green Roof, Southern France from Natural Materials & Native Plant Species

Very excited to share a series of photographs of a green roof in Southern France constructed primarily using natural materials rather than massive amounts of plastic trays and parts.

The basic design was fashioned from the LivingRoofs.org design guide - a great resource for anyone interested in constructing a green roof.  The LivingRoofs.org is, in my opinion, one of the very best resources for green roof design.  Rather than focusing on commercial advertising the LivingRoofs.org site focuses on making available important design data and examples of green roofs from around the world.

The photos here depict in chronological order the basic system approach.

Thorough research into native plants was conducted, inventorying local native plant species according to bloom time, life cycle, biodiversity value, maintenance requirements, water issues and drought tolerant qualities and more.

Interestingly, native reed, Arundo species was used for drainage along with broken and crushed tile, stone, sand and compost.

The reed used is a endemic plant, one used locally for roofs.  Reed roofs have been historically popular in the Mediterranean area and can last as long if not longer than asphalt shingles.  For an interesting review of reeds used for roofing material check out the many websites offering reed roofing products.

This project is particularly significant in the evolution of world-wide green roof technology as it is a strong statement concerning sustainability and biodiversity.

In many aspects our green roof industry has become stale and stagnant.  Most if not all systems today are plastics based, have extremely high carbon footprints with use of petro-kiln expanded inorganics for soil media, use monocultures of one or two plant Genus - most of which are exotic plants not even native to the area.

All this is great for the bank.  But not so good for site ecology.

Today, in my opinion many green roof systems are 'greenwashed' with true sustainability value.

Some say green roofs constructed around monocultures of exotic plants that require regular irrigation and fertilization may be better than asphalt roofs.  However, in my opinion, the forced use of exotic landscape plants on a roof filled with plastic trays is no different than GMO practices - forcing an unnatural product into our environments.

So this green roof in Southern France may have now set the standard for all future truly sustainable green roofs.

Native plants with ethnobotanical and biodiversity value cover the native soil and drainage materials.  The woven geo-synthetic fabric is the only material not found locally in nature - and this could possibly be replaced with hemp fabric or cotton burlap.

When I look at this roof I see the beauty of native and natural materials.  I do not see in black plastics and overused plants.

I can tell you the industry will immediately point to long term life cycling comparisons.  They will argue expanded shale lasts forever whereas green roofs using natural materials will decompose over time.  Big corporate green roof industry will argue that the mats of one or two plant Genus are extremely low maintenance and much better suited for the general population than wildflower populations that may evolve and change with the seasons.

But this roof, designed with ingenuity and a heart for long-term biodiversity and sustainability is greater in significance, in my mind, than the largest turf or sedum roof built in the last decade.

The methods, materials and plant design here now becomes a standard of sustainability for green roofs.

Certainly improvements and adjustments will be developed and implemented.  Yet the statement of a true 'green' roof leaves a lasting impression in my mind.

Enjoy the photos.  For more information contact the designer and builder on twitter - http://twitter.com/toitsverts

Geosynthetic liner


Arundo Reed

Drainage layer - Reed

Crushed tile & reed

Native Plants for Biodiversity & Ethnobotany

Using Native Plants for Green Roof Species

Green Roof Native Plants