Safety must be a part of your Green Roof. Please review the resources on this website's Safety First page before ever climbing the ladder up to the roof!

Friday, July 25, 2014

Florida Green Roofs - Know Thy Plants!

Florida summertime is hard on green roofs.  Not only are roofing membranes subject to intense weather challenges, green roof plants also are subject to intense biological and meteorological assaults.
Summer humidity may quickly kill Florida green roof succulents
We have posted notes about Black Rot fungus before here on this blog.  It never fails though that every summer persons will contact me asking why their succulents are turning brown, black or rotting.
Florida green roof succulents battle the Black Rot fungus every summer
The simple answer is to use Florida native plants (preferably evergreen species but a mix of deciduous plants will work too, depending on the green roof location in the state).  Here in Florida native green roof plants usually far outperform horticultural succulents.
Florida green roof succulents rarely become the dominant green roof plant and usually die out
Florida summers bring maximum humidity and maximum temperatures.  With daily afternoon rain showers most rooftops become pressure cookers, steaming green roof plants like vegetables in a hot wok.  If you do not intimately understand Florida roofs and how plants preform there (and this only comes from hands on learning, failures and successes are the best teachers) then your roof design may quickly end up devoid of plants as you stand there, helpless, watching the succulents literally dissolve in the heat and humidity and fungus attacks.

Tropical green roofs are a challenge.  We have listed some great green roof native plants here.

Know how your plants will perform in a pressure cooker before specifying them on a green roof here in Florida.

Wednesday, July 9, 2014

Why Florida Green Roofs Are So Environmentally Important

Here in Florida surface water can directly flow into the drinking aquifer below the ground in many places.  Here is a video of storm water flowing down into the ground through a karst connection to underground caverns after a recent rainfall event.
Cleaning rainfall runoff with green roofs and other urban greening projects before the stormwater reaches our drinking water supplies makes good sense.

Avoidance of pesticides, herbicides and lawn fertilizers and chemicals is good not only for our environment but also supports a cleaner and healthier place to live in.

Friday, June 6, 2014

Sweet Lemongrass Green Roof on Downtown Disney Starbucks Cafe

Included here are several photos of the new Starbucks Disney Orlando cafe's Green Roof!
MetroVerde Florida Green Roofs atop Disney Starbucks cafe

MetroVerde Florida Green Roofs atop Disney Orlando Starbucks cafe
The rooftop is so hot and so humid, a virtual tropical prairie.

The rooftop includes Poaceae family species growing in three inches of green roof soil media.
MetroVerde's extensive Florida Green Roofs are only 3" thick and designed to withstand hurricane winds
Green roof like these are so very important to providing so many benefits for communities.  Green roofs, like the Starbucks green roof give urban core wildlife important habitat.  The living roofs attenuate and clean stormwater, removing particulate matter and cleaning rainfall before reaching our surface and ground water systems.  Green roofs create a sense of place in the urban core and play an important role in mitigating urban heat island effect, and so much more!
Located along Main Street in Orlando Disney, the Starbucks Green Roof sets a standard for sustainable architecture
Importantly, this roof is designed to be tropical storm and hurricane resilient.  The entire green roof assembly growing system including plants are permanently attached to the underlying building.
Cradle to Cradle Sustainability, Recycling Starbucks Coffee Grounds into Green Roof Compost!

Finally, this roof is a spectacular example of cradle to cradle sustainability.  Coffee grounds from the cafe are composted and used to feed the plants.  The plants in turn clean water and air, creating a better world for growing coffee beans.

Check out the Starbucks news video with David Daniels, the creator of this amazing building.

Green roofs are so totally awesome! More soon!

Sunday, June 1, 2014

A Florida Green Roof that Failed Over and Over Again - Missed Opportunity

Green roofs in Florida must be designed for a very unique set of rooftop variables.  Time and time again I see marvelous, well designed growing systems that work most everywhere else in the U.S. fail in Florida.
The first failure.  Check out the sprinkler erosion patterns in the green roof soil media.
Beware.  A successful Florida green roof is usually based not on the growing system.  Successful Florida Green Roofs are all about the rooftop plant design.  Other than hurricane resiliency and wind uplift issues, the green roof growing system could be a simple vertical coquina stone wall and with the right plants, be green and beautiful year around.

Remnants of the sedum plants that once covered the roof.  More irrigation erosions visible in the soil media.
I do not understand why this concept is so hard to understand by some.  But hopefully we can all learn from these 'hard' lessons.

Sedums work great north of Atlanta generally speaking.  The black death fungus commonly known as Southern Blight, Sclerotium rolfsii, that is pervasively present here in the Sunshine State, apparently wiped out the entire rooftop planting in a matter of weeks.

During hot, wet summer months, Southern Blight will turn many succulents to mush.  Want to learn more about this 'ScleROTium'?  Read more here.

Here in Florida there are a few 'constants' in green roofing design.  The underlying roofing assembly should keep the building water tight.  The entire roofing assembly and green roof system should be fire rated.  Additionally, the roof and green roof growing system should be wind uplift and tropical storm resilient.

A coquina rock wall can satisfy most of these requirements.  What I am trying to say is that here in Florida green roof plants can grow in any growing system installed on a roof.

What matters most is the type of plants chosen and how they interact with primary and secondary design variables.

The 10,000 square foot, green roof system shown here was a installed on the Aloft Hotel in Jacksonville, Florida by a well known national roofing company with a marvelous green roof line of products.

It has failed and failed and failed and was finally removed.

After the first attempt, perennial peanut, Arachis glabrata, was tried as a rooftop cover.  This design too was a failure. 
Such a waste of a beautiful green roof system.

Note the perimeter dead zone on the roof soon after the second round of plants were installed on the roof.  Within a short time the perennial peanut took off, but so did the Bidens app, Goldenrod, Dog-fennel, Ragweed, Pokeberry and extremely tall 'weeds'.

Hoses were draped over the edge of the roof to supply lots of water to plants destined to failure from day one.

Whirly bird sprinklers were set up on the roof but in the end did not save the plants, rather they contributed to washing out the soil media and atomizing-spraying what smelled like reclaimed irrigation water all over the swimming pool and garden patio area below.
Florida has the deadly seven H's.  Plants must be designed around each of them.

Hot summer, relentless photoactive radiation and no matter how much irrigation was applied the chosen plants dried up and turned brown.
This roof not only failed multiple times but also presented a serious liability and safety issue.  With rooftop temperatures approaching 150 degrees F, an afternoon breeze laden with a single cigar ash could have turned the entire structure into a great big torch.
Sometimes a green roof designer will mistake 50 inch annual rainfall amounts for being spread evenly over  four seasons.  Here in Florida it is not uncommon to see ten, twelve or sixteen week droughts without a single drop of rain.  
Again, the roof and growing system here are first class.  But in Florida, a successful green roof is designed around the plants.

I recommend talking to a nursery specializing in green roof plants.  Most nurseries know what drought tolerant plants to install on the ground, and the peanut might have worked well at the hotel site on the ground.

Yet, rooftop ecology needs are nowhere near the same as ground level landscape requirements.  Leaf surface temperature differences can be as high as 80-90 degree F greater on the roof than on the ground.  Find a green roof nursery specializing in green roof plants that has worked for years in your area.

Dead green roofs are fire hazards

Wind too can have so much more impact on the roof than on ground level.  Perennial peanut's success on the ground is due to a hyper-fast photosynthesis rate and biomass creation.  The plant grows fast and covers the ground quickly.  However because the plant does not possess significant spatial or time based separation and protection of the Calvin Cycle processes, roof level heat and wind can pull the water out of the plant faster than the vascular system can resupply.

Maybe as soon as rains started the plant may have 'greened' up (possibly), yet during the dry periods an unacceptable and serious fire hazard existed.

The landscaper had previous success with peanut on the ground.  But a Florida roof is unlike the ground.

Florida green roof design is all about the plants and not so much about the system.
Note too that because there is no handrail system, personal fall protection device attachments would have to be installed to protect maintenance workers.

Maintenance on a green roof should only be done by staff trained for working on a roof with personal fall protection equipment.  Never allow a landscaper on a roof unless they are properly trained and equipped with safety gear, including a hardhat, safety glasses, high visibility vest and personal fall protection gear for starters.

But even with the proper maintenance procedures and awesome green roof planting bed, someone never figured out that  it is 'all about the plants'.

Nice green roof system plus wrong plants equals dead green roof planting.

The fort in St. Augustine, Castillo de San Marcos, is built with solid coquina rock walls, continually buffeted by strong salt laden winds and exposed to intense sunlight.  But the walls support over fifty species of plants.  No soil media and no added irrigation.  Over time populations of native plants have made their self at home.

Castillo de San Marcos plant's teach us that here in Florida it is not so much about the rooftop growing system.  It is not so much about the soil media, although the wrong soil media will not support long term growth.  It is all about Right Plant Right Place on the green roof.

So if you want to design a Florida Green Roof you can learn via trial and failure over the years, or work with a plant person who understands rooftop ecology.

We are presenting a series of design articles covering the basics of rooftop plant design.

So follow our green roof modeling discussion on the website under their Tropical Green Roofs Section.  Part one of the discussion was published a couple months ago.  Part two of the design discussion is coming soon.

The green roof has been removed.  What an amazing opportunity missed.
And for a quick revisit of the seven H's check out some of the other posts about designing Florida Green Roofs.

Once more, 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
The green roof planting system installed above was really amazing.  But forcing those plants though they may grow great elsewhere in the states, that are not suited for the 7H's, on a Florida green roof was not the right approach.

Then hiring a landscaper without a rooftop background to try and remedy the problem only magnified the issues leading to failure.

Thank goodness the landscapers did not fall off the roof.  Thank goodness a cigarette ash did not land on the dead vegetation.

It is not really about the system.  On a green roof, it is all about the plants.

A green roof is all about the plants.

Monday, May 26, 2014

Snow Loading Resource for Green Roofs and Roofing, State by State

A hot Memorial Day is beginning here in Florida!  Temperatures will soar into the low 90S F (mid 30s C).

MetroVerde's Newest Tropical Lemongrass Green Roof
Hurricane season is just a few days away and the tropical lemongrass and Fakahatchee grass greenroof in Disney Orlando is growing so fast, soaking up all the hot, humid heat.

Working on the MetroVerde Green Roof Plant Selection Model this weekend, I came across a link for guidelines to snow loads for roof design.

Yes, I know we are in Florida and Florida is listed as having a '0' lb/SF snow load design factor.  But in more northern states some of the snow loading factors appeared to be as heavy as what I would calculate the entire weight of a green roof to be, dead load rating.

It is always interesting to read about green roof issues designers in other parts of the nation and world must contend with.  Here in Central Florida it is hurricanes, cyclones, heat, humidity, extended drought periods and tropical weather issues.

Somewhere out there though, there is a #GreenRoof under snow loads.  Always have a qualified registered or licensed professional review any structural design work, be it for wind uplift or for water-snow-ice loading.  Wet roofs are very heavy.

Tuesday, May 20, 2014

Native Plant Patterns and Historical Rainfall Trends, Predictors of Green Roof Plant Success

Climate and weather patterns are the most significant determining factors of what plants will go on your green roof project and so, rather than turn on the TV I like to look at historical weather maps.
National Weather Service's Historical Rainfall Maps
Green roof plant modeling process considers light and wind to be the two primary design variables for factors affecting green roof plants.  Sunlight relevance to green roof plants and for that matter even ground level landscape designs is usually referred to in terms of 'Photosynthetically Active (and Reactive) Radiation, or PAR.  Too much PAR and the plants can burn, desiccate and wither.  Too little PAR and the plants fail to grow.

Along with PAR is the photosynthetic pathway of the green roof plant and a host of other survival mechanisms such as photoperiodism, phototaxicity and phototropism.

Wind impact too is a design variable that must be accounted for during green roof plant layout.  Strong desiccating winds can harm green roof plants with as much severity as PAR overload.  Wind can pull so much water out of a leaf that the plant's vascular system will be overwhelmed and interestingly, no matter how much green roof irrigation is added to the planting bed, the plants still die.

Micro-irrigation usually alleviates the stresses of long droughts and so on those green roofs, available rainfall impacts may not be as much a controlling design variable (though still extremely important) as wind and light.

Still I find it very interesting to study rainfall patterns across the U.S. and across the world.  Nature has laid out and sorted the different types of vegetation across our continent in a manner relating to wind light and also according to rainfall amounts.

Yes, it is a simple and very broad generalization to say that following Mother Nature's lead supports project landscape or green roof plant potential success.  

When I look at the above map depicting historical rainfall amounts published by the National Weather Service, I see three main, broad patterns.  The Northwest and the East (red and orange areas) receive most of the rainfall across the U.S.  Broad leaf dicots and C3 monocots fill these regions.  Florida and the Central Plains (green areas) receive less than average precipitation and are vegetated with great stretches of grasslands.  Here in Florida the pine flat woods which make up much of the state are filled with C4 ground cover grasses such as the Andropogons and Sporobolis species (if you live in Pensacola though you may want to choose wetland plants for your green roof due to all the rain they have been receiving lately).  Finally, the areas depicted by the least rainfall amounts (less than 20 inches per year - light blue geographic regions) are inhabited by cacti and other succulents.

So if I were designing a green roof for an area outside of Florida I'd think of this map first.

I may or may not end up following Mother Nature's lead after examine a complicated host of other factors, including client intent and if I choose not to follow then my green roof planting design better be spot on in producing the ecology my selected green roof plants will require.

The roof is a seriously harsh place to grow plants.  Use of Mother Nature's millennia of trial and error as guidelines for selecting green roof plants is smart green roofing.  It is hard to beat local native plants on the roof or across the ground.

Sunday, May 18, 2014

Green Roofs for Wildlife Habitat; Foraging, Migratory and Communal Support

Green roofs give back so much to Mother Earth and her inhabitants.  I always see this happen.  Just as soon as the #greenroof plants are installed,  wildlife appear.  The new Disney green roof planting is no different.  
Florida Green Roofs for Habitat - you build it they will come
Within minutes of the plant installation, dragonflies, butterflies and birds began to arrive on the roof.  The rooftop vegetation has now become a complex integration of communal, foraging and migratory habitat.  Check out the video of the first bird quickly arriving on planting day.

There are many, many reasons to construct a green roof, including;
  • Cleaning Stormwater
  • Reducing Heat Island Effect
  • Creating Sense of Place
  • Providing Habitat for Urban Core Wildlife
  • Preserving Biodiversity
  • Sequestering Carbon
  • Producing Oxygen, and so much more.
There are many other, less expensive roofing technologies capable of;
  • Cleaning Stormwater, and
  • Reducing Heat Island Effect
However, besides Green Roofs, there are no other roofing technologies with the benefits of;
  • Providing Habitat for Urban Core Wildlife
  • Preserving Biodiversity
  • Sequestering Carbon, and
  • Producing Oxygen
 In the long term Green Roofs may well be recognized as most responsible for preserving the heritage of our endemic biodiversity.

Because of the potential for Green Roofs to provide refuge to all wildlife, particularly those threatened and endangered by real estate development pressures and disappearing green space.

With open space disappearing within the Urban Core, vegetated rooftops provide an opportunity to ensure wildlife, birds and pollinators to continue to thrive within the city.

Saturday, May 17, 2014

Green Roof Grasses, Extensive Green Roof Atop Disney Cafe

After months of modeling different types of plants to use on the new green roof in Disney and discussing with the client we ended up selecting a Florida native grass and also a tropical grass used traditionally by cultures  from across the world for use in cooking or in the preparation of teas.

The rooftop growing are is hot and windy, windy and hot.  But both the native grass species, dwarf Fakahatchee grass, Tripscaum floridanum and lemongrass, Cymbopogon citratus, are hardy and I have full faith that not only do these plants satisfy visual requirements as set forth by the client, but they will provide years of beauty on this Orlando roof.

Here is a short interview with the grower and a look at the lemongrass plants now sitting atop the roof in Disney, Orlando.

Friday, May 16, 2014

Green Roof Soil Media Compost from Coffee Grounds

A most beautiful living roof full of lemongrass grows atop the new Starbucks Disney cafe in Orlando's Downtown Disney now.
Florida Extensive Green Roof with lemongrass, Disney, Orlando Florida
Sterling Roofing's team of professionals just finished install of the MetroVerde Extensive Green Roof, planting beautiful mature lemongrass in a special soil media designed by the University of Central Florida to help clean stormwater.  Since the cafe sites on the bank of a large lake, the green roof takes on the very important function of cleaning and attenuating rainfall before the water reaches the Lake Buena Vista chain of waterbodies.

Florida's (and the rest of the world's) water supplies are in great need of responsible eco-stewardship.

The tens of thousands of pounds of soil media now supporting the green roof plants has less than 5% organic content.  So we will be periodically adding trace amounts of compost made from the cafe's recycled coffee grounds to feed the green roof plants.
Coffee grounds ready for compost recycling, great for #GreenRoofs
Importantly, these recycled coffee grounds are typically available for you to pick up from your local Starbucks store.  Judy has used these grounds in her Florida permaculture garden here in our backyard.  Fresh grounds must be thoroughly composted just like any other organic matter before use.  When they are composted though the resulting organic matter is like black gold and our plants love the organic matter.  You can read more about the project as it progresses, including an interview with UCF's Mike Hardin about the soil media on the project green roof website.

Additionally, as week or so ago I posted another blog post by Green Prophet about green roof plants being grown in composted coffee grounds at the University of Haifa's Kadas Green Roof Research Center, so this is idea is catching on across the world!
Black gold compost for the #GreenRoof made from recycled Starbucks coffee grounds
Recycling coffee grounds is an important part of cradle to cradle sustainability for any cafe or restaurant.  Recycling coffee grounds into compost for a green roof is especially important; for the plants benefitting from the rooftop compost give back so much to the environment.  They clean the air, purify the rainfall runoff, provide habitat, pump out fresh oxygen and so much more (see the previous post for a list of many, many green roof benefits).

Green roofs integrate so perfectly into sustainability.  Green roofs provide so much social, economic and ecological benefit.  Recycling coffee grounds to make nutrient packed compost for rooftop plants is just one small but very important component in the process.

Sunday, May 11, 2014

Green Roof Benefits; Social, Economic and Ecological

Florida Green Roofs offer so many Ecological, Social and Economic Benefits
Laying wide in the middle of the night thinking of all the benefits green roofs offer I had to jump up, make coffee and write the list out, all those wonderful green roof benefits scrolling down through my wide awake midnight mind were so exciting.  Green roofs offer so much.  Here is my midnight green roof benefit list.  See more green roof benefit sketches here at the Coffee Shop Green Roof Site!

Green roofs and living walls offer so many benefits, including;

  • filter rainfall
  • minimize runoff
  • cool buildings
  • provide habitat
  • sequester carbon
  • reduce greenhouse gasses
  • offer beauty
  • protect endangered species
  • urban heat island reduction
  • provide fresh oxygen
  • feed pollinators
  • optimizes site footprint
  • replaces stormwater pond
  • saves energy
  • insulates
  • supports biodiversity
  • creates greenways
  • food for cities
  • organic produce
  • rooftop permaculture
  • economic opportunity
  • roof herb gardens
  • teaching opportunities
  • seed production
  • high tech farming
  • urban core economics
  • city farming
  • native plants
  • wildflowers
  • succulents
  • weather station data
  • rainwater harvesting
  • kitchen composting
  • roof worm production
  • rooftop bees and honey
  • rooftop zen gardens
  • rooftop wetlands
  • recycle HVAC condensation
  • materials engineering
  • solar power integration
  • educational rooftop videos
  • marketing opportunities
  • community cohesion
  • school science projects
  • innovation laboratory
  • soil media science 
  • botany classroom
  • roofing efficiency studies
  • eco-blogging possibilities
  • media opportunities
  • outdoor science classroom
  • wind design platform
  • wind power integration
  • avian refugee
  • butterfly roofs
  • beauty for urban cafes
  • therapeutic healing roof
  • rooftop gardens increase rent
  • green roofs improve leaseability
  • green building certification
  • and so much more!

Green roofs are simply so amazing!

Friday, May 9, 2014

Green Roof Logistics, Ensuring Construction Access for Soil Media and Plants

Sometimes the hardest parts of a job are the unforeseen issues.  That is why it is always so good to hire a veteran team of the trade, staff who understands what plants or soil media to use and the proper growing system to install.  
Florida Green Roof construction requires plenty of access to the roof and staging areas for plants
But just as important to a successful green roof install as the plants or soil or the system is the overall concept of staging and logistics.  If you can not get soil media or plants up on the roof then you are not going to have a green roof.  This knowledge usually comes through the school of been-there-done-that.

Contemplation of access issues to a green roof project site is a topic not usually discussed, one many often take for granted.

If there is no access up to the building then soil media may have to be carried up a ladder in buckets
Even on a small green roof the task of moving three or four cubic yards of soil media (thousands of pounds) up ten feet in the air is a daunting task.   When access to the side of the green roof building is clear and free of construction material or tools then the lifting up of soil media super sacks or heavy ballast is much easier accomplished.

Carrying five gallon buckets of soil media up a ladder is a tough way to apply growing media to a roof if there is no access for a lift truck.
Green Roof Soil Media is sometimes delivered in sturdy bags called "super sacks"
Our roofing partner, Tad Davis of Sterling Roofing told me a while back something well worth remembering for any green roof project.  Tad said "Kevin, I always write in a contract something to the extent that appropriate access to the roof area must be provided by the general contractor".

This is really good advice.  Most construction sites are filled with either waste bins, stacks of materials or large pieces of very heavy equipment.
Green Roof Soil Media occupies a lot of space.  Make sure your job site can accommodate the super sacks
Staging soil media and green roof plants requires a significant amount of space.  One does not store thousands or even hundreds of one or three gallon sized plants in an area just large enough for a pallet or two (or four or five).  The same applies for a tractor trailer load of soil media stored in super sacks.

Properly planned, soil media and plants can be staged to a roof quickly and easily.
View of the construction site from the #GreenRoof planting bed
But if there is little or no access then the trips up a ladder with that half filled, heavy five gallon bucket can take several days, probably more like several weeks.

Good communication with the job site superintendent and general contractor is essential.   Coordinating schedules and juggling equipment and material storage areas of the many sub-contractors can be tricky. 

Finding out that there is no access to the roof on the day plants are to be delivered can be disastrous in many ways.  Plants can end up being run over, trampled on or left unwatered while they sit on pallets outside the construction are perimeter.
Remember, on Florida Green Roofs practicing 'Safety First!' is so important!
Always think about logistics.  Consider when and where the plants will be stored just before install.  Consider how large quantities of soil media will be brought into the construction site.  Visit the site on a regular basis before soil media and plant install, even after coordinating with the job superintendent.  Make sure your planned on staging areas and roof access is really available.

Sometimes the  unforeseen, seemingly unimportant job factors are those that can seriously delay a project.  Good planning and proper communication can go a long way towards ensuring a timely and successful green roof project.

Thursday, May 8, 2014

Florida Low Impact Development, A Native Plant Bioswale Success!

The Lasalle Street storm water bioswale is growing into its third spring, a little over two years old.  I know because my aorta dissected during the middle of the project's schedule. Ugh.  A first year plant and project review can be read here while photos and several posts of the original planting project can be found here.
Native plant Bioswale, Lasalle St., Jacksonville, Third Spring's Growth

Today the array of native plants installed by a marvelous group of volunteers has grown into their own prime, lovely Florida grasses, native shrubs and the wonderful cypress tree, Taxodium spp.
The Native Plant Bioswale was originally planted in late 2011
Bioswales are rapidly becoming one of the more popular approaches to cleaning urban storm water runoff and most are using native plant species.  The University of Florida IFAS Extension Service has produced a helpful, informative publication on the design and benefits of urban bioswales for Florida cities.
The Bioswale has matured into a prime example of a successful low-impact development project

We think of plants on green roofs providing many benefits, including;

  • Sequestration of Carbon and mitigation of CO2 greenhouse gasses
  • Positive production of fresh oxygen daily
  • Cleaning rainfall runoff by filtering out particulate matter and attenuating flow rates
  • Uptake and sequestration of nutrients such as nitrogen and phosphorous
  • Habita creation for small to large wildlife and birds
  • Beauty for us humans
  • Urban Heat Island Effect mitigation - cooling of the cities
  • Keeping our creeks, lakes and rivers clean
  • and so much more
Bioswales provide the same benefits as green roofs.  Bioswales are like a green roof but are located directly on the ground instead of a rooftop.
Bioswales, like Florida Green Roofs provide an array of ecological and environmental benefits

Plants are so amazing, especially Florida native plant species.  They work 24/7 to help keep our world clean and that is just the start of what they really do for us!
Lasalle Street Native Plant Bioswale's Third Year Growth

Tuesday, May 6, 2014

Tree Ring Music - Melody in the Urban Core

I love plants.  When I heard about tree ring music on the record player, I had to share it here.  And we do have trees on some of our green roofs, like the Grancy Greybeard atop the Breaking Ground Contracting Green Roof.  I like the Acer music so much.  Enjoy!
For a full listing of tree ring music see Bartholomäus Traubeck's website

Monday, May 5, 2014

Florida Green Roof Plant Root Structure, Horizontal Root Architecture

Green roof plant architecture is an important biomechanical component of all green roof design, construction, installation and maintenance activities.  In the end a green roof is first, foremost and all about the plants.
Florida green roof plant root architecture - beautiful horizontal root structure
Without the happy, thriving plants, there is no green roof.  Possibly a brown roof but not a green roof.

I think the Florida extensive green roof root structure depicted here in these photos is simply beautiful.
Green roof plant root architecture -  horizontal root structure growing into anchor
An understanding of green roof plant root architecture is one of those fundamental design talents that every green roof professional should possess.  Some of you will have learned about green roof plant root architecture from years of observation, hands-on planting and study of how green roof species grow, others through educational programs.  I examine root structure across green roofs every chance I get.  

My preference is shallow soil media and unimpeded horizontal growing space for green roof plant roots.  I do not like sectional barriers that may limit horizontal root growth and ultimately cause root circling-root bound growth patterns.
These grasses possess good green roof plant root architecture - not too aggressive but sturdy
Another reason I prefer unimpeded horizontal root growth opportunity on a green roof is because I believe green roof plants will over time, relocate themselves or their offspring to the best place on the roof for their particular species survival.  Yes, plants do move through root biomechanic mechanisms.  It is poor planning to restrict green roof plant root architecture any more than necessary.  Just think of how many times you may have pulled a plant from a nursery tray or pot with twisted and circling roots that have practically strangled the plant.
An anchor system may keep plants on a roof during tropical storms
In addition to catering to the green roof plant through design of open space for root growth to occur we like to provide the roots an anchor to grow into.  There are many different approaches one can take when providing an anchor, including cables, mesh, netting or fabric.  By permanently attaching the anchor material to the roof you create a green roof plant growing system that may be resilient to tropical storms or cyclone winds.
Unimpeded root growth prevents strangulation of green roof plants
Using this approach we have created green roofs that have stayed in place when blown with 130+ MPH winds.

The grasses in these photos show this principle in practice.  Using a small, mock up green roof growing system these plants have embedded their roots into a nylon fabric, creating an impressive anchoring form of root architecture and growing in a well defined, horizontal fashion.
A good green roof plant architecture will create a monolithic growing mat with plants anchoring each other
While some prefer deep plantings with roots reaching down vertically, we find horizontal root structure strategically places roots in an optimal position to absorb those frequent one half to two inch afternoon rainfalls here in Florida.  Rain water usually stays in the top inch or so of the green roof soil media.  With a horizontal growth pattern, green roof plants can take advantage of this rainfall where deep roots may have less rain reach down into deeper soil horizons.

If you are wondering, the photographed soil media contains less than 5% organic material.  The bark-looking chips are actually ground recycled rubber tires.  This is an experimental soil media, one we do not use on actual green roofs due to fire ratings.

Know your green roof plant architecture.  Remember, in the end a green roof is first, foremost and all about designing a growing system that keeps the green roof plants happy, healthy and surviving in the long term.

Thursday, May 1, 2014

Intense Rooftop Aquaponics - Amazing Rooftop Garden!

Check out this impressive Rooftop Farm - Aquaponics - garden video.  It is amazing just how much food is being grown within a small rooftop area!

Efforts like these are truly inspirational and may hold the answer to feeding the world's future population.

Wednesday, April 30, 2014

Green Roof Roof Drains Reference Links

Sizing Roof Drains for Green Roofs (and All Roofs In Fact) is Important
I spent a good hour last night worrying about a new green roof we are working on, and how it would drain with the roof drains designed by the project architect.

Right away I will say that I am not qualified to design roof drains.  Sizing roof drainage is a function for a qualified architect or engineer, not a green roof plant person.  However, I still worry.

Living in Florida I have seen some heavy and prolonged downpours.  Last night in fact, across the panhandle area of western Florida, rainfall totals reached almost 24".  That is a lot of water to move off the roof.

Of course storms dumping huge quantities of water do not happen every day.  But I still want my green roofs to drain.  Most green roof plants do not like 'wet feet' so to speak and I certainly do not want the green roof plants to float off the roof.

Yes, I ultimately trust most architects and engineers on their designs for they are accomplished professionals.  But for those occasions, like last night I feel better after a second opinion.

Now I am not vouching for their accuracy, but there are several easy to use Roof Drain Sizing calculators published across the internet.  It only takes a few seconds once you have the approximate square footage of the roof you are wondering about to see just how many roof drains are needed for different areas of the country.

Do not use these for design, but like last night, when I was wondering if the architect got the design right, these sites may be a good second opinion.

So stop worrying and check out some of these Roofing Drain Sizing Calculators:

Tuesday, April 29, 2014

Coastal Green Roofs and Coffee Grounds

Today I wanted to mention a couple of projects and posts that have really caught my eye as leading edge attempts to bring vertical green to structures.

The first is an amazing project called Casa Vallarta in Puerto Vallarta, Jalisco, Mexico by Zona Verde MX and Cynthia Villaba.  This project sits on the Pacific ocean seashore.  Kudos to the designers in overcoming salt, wind, heat and hurricane impacts to create a beautiful 7,600 SF green roof and 3,000 SF living wall.

I am so totally in love with this wall system and roof.  I really want to visit this green roof and living wall someday. What a great time lapse and construction video too!  Check out @ZonaVerdeMX tweets too for vertical green Mexico.

For more information check out the post here as the project was selected as GreenRoof and GreenWall project of the week by Linda Valazquez and

Secondly, this post by Green Prophet about growing green roof plants in coffee grounds caught my eye describing efforts by students and staff of the University of Haifa.  This is true sustainability.  Yes, I know coffee grounds are organic and will degrade over time and have other issues, however as as green roof soil amendment they are unique!

I am especially interested in coffee grounds as compost.  MetroVerde is installing an amazing green roof on a coffee shop in Disney, Orlando as we speak (great job Jimmy and Tad at Sterling Roofing!)

MetroVerde Florida Green Roof on Disney Coffee Shop - more soon
So much to learn about vertical green.  So many benefits!

Sunday, April 27, 2014

Tropical Storm Season is Here, Is Your Green Roof Ready?

It is that time of year again.  Soon there may be cyclones in the Atlantic, wave after tropical wave forming off the African continent and storming westward across the Atlantic.

If your green roof has a parapet then you are lucky.  Most testing has shown parapets minimize wind damage to a green roof - though in a large hurricane, all bets are off.

Even if your green roof does not have a parapet it can still be designed to minimize tropical storm wind damage.

The video here is of a small green roof in Jacksonville, Florida on August 25th, 2008 when Tropical Storm Fay pummeled the northeast Florida area with over twenty inches of rain.  The video shows how the roof reacted to gusts up to 50 mph.  Wind speed was recorded using an ExTech anemometer.

The roof shown in the video does not have a parapet and is sloped.  The video illustrates how the irregular surface of he vegetated roof interrupts wind generated uplift that can damage asphalt shingle roofs.  The plants range in height from two inches to six inches and can be seen moving back and forth in response to the wind.


Wind racing across a flat surface can create lift - or a vacuum - and literally lift the shingles or roll roofing up off the decking below.

The plant habit acts to break the shear flow of air, creating turbulence and working against damaging uplift.  Planting more wind tolerant plants, such as some succulents or grasses may actually create wind breaks in a manner similar to the way a parapet would act.

Another important quality of a well designed green roof is the drainage factor.  The roof here is allowing a rapid drain of roughly 18" of rain over a 24 hour period without washing out. 

Monolithic hurricane mats used as the basis of the planting system allow for quick drainage of the stormwater and create a mechanism where plant roots can attached and anchor themselves to the roof all the while holding soil in place.  A well established root architecture  is important  for tropical green roofs subject to high winds and heavy downpours.

We will always deal with the 5 H's here in Florida - High Heat, High Humidity, Hard Frosts, Hurricanes and Hard Desiccating Winds, but with good green roof design your Florida Green Roof can hopefully withstand a severe storm, including tropical storms!

In the meantime, there are some precautions the green roof owner can take to prepare for tropical storm season (May 15th for the Pacific area and June 1 for the Atlantic regions).

At a minimum, we recommend;
  1. No large trees on a roof.
    1. Small shrubs and small trees may be used successfully depending upon the final design.  This may seem like a common-sense guideline but people try to put all types of tall, large trees on patio or garden roofs.  During a 130 mph cyclone, the tree may be blown over and may cause damage from the fall against the structure or to the street below.  It may also become airborne if the winds are strong enough.  Growing up in Hialeah I saw plenty of hurricanes come through our area and witnessed first hand the power of these storm events.
  2. Anything and everything on a roof should be permanently attached.  
    1. Walkways should be constructed from a permanently attached TPO, EDPM or other mat and permanently affixed to the roof.
    2. No loose chairs, tables or other items should be present.  If you wish to have a chair and table stay on a roof during a cyclone, they must be permanently attached.
    3. All green roof components must be permanently attached to the structure.
    4. Any trays, plastics, pots, containers or other green roof components must be permanently attached to the building structure.  Florida Building Code does not allow for loose items to be installed on a roof - they must be attached.
    5. Green Roof Irrigation components must be permanently attached to the roof.
  3. Make sure all tools and gardening utensils are picked up and put away.
    1. It is very easy to forget the pair of shears, scissors or pliers on a roof.  Remember what you were using and where you liad them.
  4. Plant selection should be focused on those species that have historically survived cyclone and hurricane incidents.  There are several good books available at most bookstores here in Florida on proper cyclone resistent landscaping and many resources on the web, such as the Brevard County Landscaping Guide for Hurricane Areas.
  5. Check on the NOAA National Hurricane Center website daily.  The NHC webpage is a wonderful resource, full of links to climatic data.
Always use a green roof design or green roof system already proven in actual field trials with hurricane simulation testing.  Watching a green roof blow off during a storm is an avoidable event.  Due diligence upfront and preparedness is important for green roofs in hurricane prone and cyclone impacted areas.

Friday, April 25, 2014

Florida Green Roof Teamwork

Teamwork is so rewarding.  I am amazed by what people can accomplish if they combine efforts, each contributing their expertise.  This is why Tad David and Jimmy Sterling are so awesome.

Drainage mat, hurricane weave and LED light brackets are installed in the MetroVerde Green Roof system
When I see certain plants growing on walls or roofs, Tad sees how to attach them and Jimmy sees how to make it all happen.  It is an unusual combination of plant biology, mechanical & chemical technology and business.  And it works.

All green roof projects present their challenges.  Some are super challenging.  We have a beach front green roof three stories up in the air with a very small parapet that will have to survive daily winds most green roofs never see in a lifetime, not to mention the thick layer of salt the plants will be coasted in and seasonal tropical storms.

The green roof Tad and Jimmy are presently installing with me is no exception to the unique.  The rooftop garden is highly visible both in physical exposure and also in noteriety.  It is going to be awesome.
Safety is so important while installing Green Roof systems, here workers utilize Personal Fall Protection Tie-Offs
The roof is in a high wind velocity area so it will feature grasses; primarily lemongrass along with some native grasses.  If you have followed the blog you know about my attraction to C4 photosynthesis pathway mechanisms.  Some grass species are so drought tolerant.  Of course there are a myriad of other plant considerations, from fire to growth behavior and visual presentation.

The roof is also sloped, a pretty decent slope and the primary roofing layer is a slick when wet TPO material.

The green roof will be quite heavy too.

And there is only a six inch parapet.

Think of a downhill NASCAR race on top of the wet roof with all the cars  slamming on their brakes, trying to stop.  And then add hurricane winds.

How do you keep the rooftop garden on top of the building?
A sloped Green Roof must stay on the building and not slide off.  Green Roofs are heavy.
Now add some really cool LED lights in the midst of the plants, integrated with the irrigation.

Language, to me is spoken in terms of the botanical.  I see stomata, vacuoles, flowers, leaves, xylem and phloem everywhere I look.

Tad sees fasteners, mechanics, materials and schedules and communicates these to me and his crews in a manner I could never do.

Jimmy's vision guides us down the sustainability highway so we don't get struck on the on and exit ramps.  For instance, I gave Jimmy a prototype vertical green product the other day and he already has improved, streamlined prototypes being fabricated for field trials.

Green roofs are not just a vision of a gardener.  They may be conceived of a designer's vision of foliage everywhere.  However when given the benefit of a team that understands plants, roofing, safety (don't forget OSHA) and business the final product can be innovative enough to allow that NASCAR race on top of a building so to speak.  At least the project can grow beautiful rooftop gardens and stay put on the roof in during cyclones (hopefully).

Thanks for your greenroom passion, team!