Non-Irrigated Green Roof - 1 Year and Still Going Strong at UF Test Center

Call Kevin for more information on your light weight green roofs 904-294-2656.

Corie's Green Roof - Jacksonville

Corie Baker is the architect behind the famous Villa Paraiso mansion on the St. Johns River in Jacksonville (see builttotallygreen.com).

Her and her husband have a flat roofed addition on their historic Avondale home - and they wanted a MV Green Roof.

Here is a green roof base installed today.

Watch for more pics as the plants are installed!

Kevin

Flat Roofs and Sloped Roofs, Green Roofs for both in Florida

Remember though - the plants you have installed on your green roof generally do not like wet feet, so provide good drainage!

Our field panels have shown that green roof systems in Florida with excellent drainage - nothing to hold the water in the soil - grow the healthiest plants.

Many take the opposite approach and install a water retention layer (material like a sponge - and a good way to grow mold and culture up plant diseases). Though a water retention layer will work when rain events are a week apart - allowing for drying time - the retention layer becomes a detriment during periods of daily rainfall events. All of a sudden the drought tolerant plants are subject to wetland conditions.

Therefore - we have found green roof plants (Extensive Roofs - we do not work with the heavier, more costly intensive roofs) - on sloped roofs do the best.

Moreover, engineered soils will last longer when well drained. Water has a tendency to act as a separation agent (dig down into your backyard and you can tell how high the ground water rises because the water separates organics and inorganics into layers).

Remember - well drained systems last longer and grow healthier plants!

Native Plants and Florida Green Roofs

Every good plant person wants to use native species in their landscape. At least we all confess so anyway. Certainly the term is politically correct and in vogue by most regulatory agencies, municipalities and various conservation groups, native plant societies and NGO's.

I have just concluded several years native plant trials on flat and sloped green roofs - extensive green roofs that are not irrigated or fertilized. I've traveled across the State of Florida to various plant nurseries and native plant nurseries. I've purchased and accepted as free native plants to try on the roofs. We've watched them through 20 degree F weather and then through 150 degrees in the summer. Earlier this year we had an 11 week stretch where we received less than 1/2 inch total rain.

Roofs are a rough, tough place to put plants. Most have little concept of the harsh and unhospitable environment most roofs possess. The winds alone over Florida roofs are desiccating and will dry out most plants in a matter of hours.

Plants with high stomata to leaf surface ratio are doomed on a roof. Plants that cannot tolerate high humidity and sever swings in daily temperatures - 60 degrees F is not unheard of - are also doomed.

But Florida's sandhills and xeric uplands support native species with a promise of being able to tolerate the ultimate test of life on a roof.

Native grasses make it for a season or two, but the constant winds weaken their resistance and ultimately they fall prey to extreme drought or cold. We've looked at the leathery leafed native vines- railroad vine, for instance and again - though it comes back when planted in the ground after a hard freeze - it has not reliably recovered on the roof.

The native Allium canadense - or nodding onion - also shows promise.

Yucca's, such as the native Adam's Needle are strong contenders however they have a tall habit and may outgrow a roof.

Of course there are many South African and European plants that survive and prosper in these conditions. But they are not natives.

So why not irrigate? We have a water shortage and a mold problem in Florida. The first time an irrigated vegetated roof leaks and causes building mold issues, precedent will be set for every other building with vegetated roofs and mold, regardless of a leaking roof or not.

And Florida has a serious water stewardship issue. 50% of all potable water use right now is for irrigation. Good enough reason to not irrigated a vegetated roof.

Many will never be convinced of the irrigation issue - but we are making progress. Native can work. Finding the right species for the right roofs takes time.

The above pictures are of Elliot's Lovegrass on a flat trial panel and Allium canadense on a sloped roof.

Send me your thoughts... & Happy green roofing!

Native Plants for Green Roofs - Florida

Using Florida Native Plants on green roofs can produce positive ecological results. First, native plants should be acclimated to the local climate and ecotone thus affording greater long-term survival. Second, native plants on a green roof will provide habitat, food and foraging opportunities for local and transient wildlife.

Thirdly, the use of native species is an important step in moving towards restoration of original volumetric green in our Urban Core.

The species pictured here include dwarf love grass, muhly grass, Carolina jessamine, a naturalized Florida rosa species and others.

Happy Green Roofing! Kevin

Florida Green Roof Plants Withstand the Hard Freeze of February 5th, 2009

Look at the spread in the temperature range. It was in the low twenties at 5:30 am this morning - now at noon the surface temperature of the trial asphalt shingle roof is 120 degrees F.

How do the plants survive?

The above pictures were taken this morning about 7:45 am.

The plants were frozen solid. But they've thawed and are enjoying the sunshine now!

Happy Green Roofing. Kevin.

Propagating Green Roof Plants for Florida Green Roofs

Propagating plants for green roof projects here in Florida is an important component of a successful Florida GR project.

Knowing a plant was raised in the same ecotone where it will ultimately be used is important. This not only secures LEED credits for local material use (and other credits) but it helps in knowing the plant can survive local climatic conditions.

My general rule of thumb is that, here in Florida, a green roof plant should be grown no greater than 150 miles north or south f the project physical location - no general limit on east/west other than the local limits for LEED credit.

The roots shown on the succulent leaf here developed on their own, on a leaf dropped as mother plants were being pruned, a testament to the hardiness of plants. The above pictures also show the importance of saving pruned plant material for propagation - and in doing so being a good steward of resources.

Happy Green Roofing!

Florida Green Roof Project Continues with the addition of more cold tolerant yuccas....

The New Florida Green Roof Project is moving forward! We've added several new cold hardy varieties of Yucca! Stay tuned for more pictures!

Hard Freezes and Florida Green Roofs - Winter (Hard Freezes - one of the many 'H's GRs face in Florida)

Judy and I have been scurrying most every afternoon to cover plants as temperatures have been dropping into the twenties here in Jacksonville. Looking at the Weather Dot Com it appears that around Tallahassee the mercury has hit the low twenties several times. Walking by our green roofs, I look up with frost blanket in my hand and want to climb up and cover the plants. But I don't.

Our green roofs serve as our best trial panels as we've said many times before. I have finally reached the confidence level that allows me to know the plants will survive. Still though, many of the plants on our green roof are hard to find varieties and the cold north winds are desiccating, unrelenting and potentially fatal to humans, animals and plants.

I am always proud the next day to see the plants stand straight and soak up the sun's warmth. Balancing the choice between those plants, like the sedums that can tolerate extreme cold but melt in the fierce pressure cooker like humidity laden summer heat - and the succulents that can take the tropical heat but not the cold has been the key to success.

There are not alot of plants that fit into the category of withstanding both of the above limiting factors. Then you add long periods of drought and long periods of innundation to the model as inputs and the list of plants that will survive shrink even more.

Finally add the requirement the plants must still look good and not be dormant to the above and the list really becomes small....

So as I await days light to see what damage, if any has been done and add the findings to our resource base - I hope the coldest night so far of 2009 will produce the same positive results as those before.

Happy green roofing in Florida!

Succulents for Green Roofs and more Sunday Night musings...

The blog data here is a continuation of my previous Green Roof blog. Feel free to refer back to the site to my new Green Roof blog because it does contain alot of information - and I will be posting the same info both here and on the Green Roof for Florida blog for some time.

We use succulents in most all of our green roofs. Succulents are an excellent green roof plant in many different ways. Succulents generally store water in their stems and leaves in significant quantities. Cacti leaves are practically non-existent and most photosynthetic functions in cacti occur in the stems. Succulents have stomata on all green surfaces but at much lower surface densities than most other plants.

Because succulents store water they can survive and in most cases still 'look good' after a significant drought. Another benefit to succulents is one of offering a deterrent to fire through their water filled leaves and stems.

Some other drought tolerant non-succulents such as the sages and grasses produce flammable volatile oils that can add fuel or accelerant to a fire.

Most succulents do not need fertilizer in quantities required by non-succulents. We have seen the base nitrogen content in rain provide sufficient nutrients for many green roof succulents.

Succulents also do well in well-drained soils that will wick and absorb a minimum amount of water.

Today engineered soils, such as the MetroVerde engineered soil blends have taken the place of most 'dirt' on the roof.

And finally, we are now prepared to say in our opinion, the green roof plants we propagate and raise like round rays and pots better than square ones.

After viewing first hand the growth qualities and characteristics of our green roof plants grown from seed in round and square containers, and cuttings in both, we believe the round container has less negative impact on root formation than the square shape.

Although there is not a huge significant difference, we've noticed a definite difference in size and in transplanting issues.

Unfortunately round pots are not as space efficient as square pots.

Has anyone out there seen studies conducted on the difference between square pots and round pots? I'd like to hear from them.

Happy green roofing!

Green Roofs in Florida and Cooler Weather

It is becoming cooler and night now and well should be - it is almost Thanksgiving & most green roof plants on our projects are very happy that the long and tortuous ordeal with Florida's heat and humidity is almost over for a season...

Many of the plants bear battle scars from Tropical Storm Fay (way, way too much water) and the ever present afternoon humidity bath.

The Sempervivums are starting to revive...you can see new growth expanding out from the middle of the plant, the brown, wilted areas falling away from the perimeters.

This is the time of year for dormancy for some of the sedums - - they are turning brown and melting away while others are just melting after a long stressful battle with the Florida humidity.

Iceplant is doing well. Iceplant planted on the ground melted out during T.S. Fay but those clumps on the roofs actually thrived.

Interestingly, the allium likes the cold weather too - its leaf blades perk right up.

So now is a major time for seasonal change in North Florida for green roofs. Stay tuned for more updates!

Green Roofs - Another Volunteer Vegetated Florida Roof

Walking the streets of almost all cities and towns you can see plants growing in the toughest of places.

They grow in the cracks between the concrete in the middle of the busiest streets and interstates. They grow up walls, peaking from the tiniest of crevasses. The grow in gutters and in roof seams. Give a plant a chance and many species will grow just about anywhere there is a little sunlight and occasional water or moisture.

The philosophy we carried with us over the years of experimenting with how to successfully grow plants on roofs was simple. It was based on watching plants grow in the most inopportune places.

Our goal was to design a vegetated or green roof that inherently had the following characteristics: 1. Low weight, 2. Reasonable cost, 3. Leaves and color all year, 4. fire resistant, 6. heat, humidity and hurricane resistant, 7. Florida Department of Community Affairs approved, 8. treats stormwater, 9. provides habitat for wildlife, 10. was low maintenance, 11. could be used on slopes (we can go vertical), and finally - a roof that would last - season after season.

We believe we have developed what we set out to do!

Call Judy at MetroVerde - 904-294-2656 to find out more about your new green roof!

Florida Green Roof Project Continues!

The new Florida Green Roof continues to grow with more and more succulents, agaves and cacti daily!

Once the structural plantings are completed the oobleck will be added around the plants, allium seeds sown and then wait for the plants to take off and fill out the mats!
Contact Judy @ MetroVerde for your green roof!

Update - Florida Green Roof Project - with installation of green roofing plants!

Plant installation on the New Florida Green Roof Project proceeding! Looks for more updates soon!

Florida Green Roof Project - Green roofing at dusk...

The plants are under installation. The days are getting shorter. The nights cooler. It hasn't rained for a week and the only water the plants are receiving is the blanket of heavy morning dew.... This weekend we should make good progress with finalizing the plant installation!

Florida Green Roof Project - cleans stormwater - mat installation phase!

First Step to mat installation (once the sub-roof has been prepped or the liner applied over the existing roof - is to measure and cut the mat!

Another Green Roof Video - Florida Green Roof Construction

See Previous Post for more on installing a liner on an existing roof in preparation for a new Green Roof!!!

Enjoy the Video!

Brown Curly Q's on the Alliums. It has been a while since we've had a rain event...Florida Green Roofs

Other than the tale tell sign that the alliums are aware that it has been a good while since rain has moistened their roof top beds, the MetroVerde Extensive Green Roofs I've been following are looking good.

The Semps have really enjoyed the respite from the humidity and are looking perky and green! Though you do not see them here. I'll post a pic of them tomorrow.

I was out most of the day today taking the International Society of Arboriculture's certified Municipal Arborist exam - I thought it was a hard test - but as I was reviewing the questions, several key phrases jelled in my mind about adding small trees to the MV Extensive roof panels and after consideration all afternoon - I think it will work!!! But of course, as always, we will vet in the field through many tests. Please be sure and stay tuned for more info as the field trials take shape.

Back to the alliums in a second - but first - we are going to develop a spreadsheet for the blog that will allow us to post temperature readings of on deck asphalt, on deck vegetation, below deck asphalt and below deck vegetated sampling points on a set of Jacksonville, Florida roofs. We will keep the readings posted year around for our interests and comments. Right now I am seeing October mid-day below deck under asphalt readings averaging 128 degrees F while below deck under extensive vegetation mats of 81 degrees F.

We are also running LC-50 tests on straight rainwater and then rainwater runoff from an asphalt shingled roof and a vegetated roof. It looks like the only roof that doesn't kill the fathead minnows is...well - we need to wait for the final data.

OK alliums. As you can see in the photo - the alliums are feeling the semi-drought. Though only a trained eye would probably see the stress indication in the leaf blade tips - it is there. But this is how alliums respond to drought. We will keep posting pictures until we experience a decent rainfall event. Never fear for these plants though - they are tough, tough, tough. Judy and I have worked with these plants for years and years. You cannot kill them and when you trim the blades back you can almost see them grow back out!

Can you tell from the photo? Lots of lush green - but look for the thin brown tips. It has been three weeks since a solid rain. If this was a roof with a modular tray system - here in Florida my bets are that you'd have a dead mess. Mat systems are so much better suited for the three Florida H's - Hurricanes, Heat and Humidity...

Until tomorrow! Happy Green Roofing Dreams! Kevin :)

Florida Green Roofs - Prepping the mat with expanded mineral material - perlite, vermiclite, expanded clay, agar, trace minerals, and more!

Episode Three - prepping the planting base - prepping the mat. Lots of standards and regulations, common sense precautions and just plain good BMP's - Best management Practices come into play now that the mat is rolled out. So we've talked to death the reason why we don't like trays and modular systems....Hey I heard of a roofing company somewhere is South Florida who just installed a system of trays on their roof - and the plants died...

But the reason we choose mats is not the reason we don't use trays. The reason we choose mats is because with a mat, the green roof's plant roots can grow as far north, south, east or west they want to grow. No circling (as in trays) and no self strangulation in a couple of years (as in trays).

Sure - maybe Plant A will Run into Plant B. Instead of root circling and strangulation though, the roots will compete with each other and the stronger plant will go onto to survive. The important note here is that there is always coverage - though one may dieback, the stronger or more suited plant survives. The mat advantage has proven itself on the Dearborn, Michigan Ford Motor Company 10 acre roof.

OK - back to the soil...

Wouldn't it be easiest just to fill the mat with dirt from the backyard? - Maybe so - but I wouldn't do it. Think of the weeds, nematodes, fire ants, etc you may be digging up and placing on your roof.

Moreover, ASTM has specifications written for dust and organic matter and more for green roof soil systems. The MetroVerde engineered soil (MV GRP) mixture we use is a proprietary blend - and we add soil goodies to it! I think of it as a stabilized outdoor hydroponic system!

So lay out a piece of plastic sheeting on the ground in an area you won't be walking - please note that if you have outside cats or dogs - they love to use a rolled mat system as a huge litter box! Take precautions!

Roll out your mat on top of the plastic, add the mixture of perlite, vermiculite and expanded clay. Apply the tackifier initial layer. Sow desired seeds or installed pre-grown plugs and reapply tackifier.

We'll explore soil mixtures and tackifier solutions (there are many of these sticky mixtures) in an upcoming post. In the meantime - Happy Green Roofing!!! Kevin

New Florida Green Roof Project - THE MAT !!!!

One of the basic principles of a successful green roof is the base mat. Mats are the preferred green roof base system for Florida Green Roofs - as we have discussed countless times before here. The reason is simple - the roots in plants secured in trays or modular components eventually reach the tray walls and begin to circle around, eventually strangling themselves to death - remember going to the nursery and buying pot or root bound plants - they did not live long....

Welcome to the mat episode...the mat was delivered today! We will unroll it, flatten it out and begin adding the expanded clay, other non-organics and the tackifier (agar based). Sound complicated? Naw.... Watch for the next episode - to be posted later tonight after we do the above tasks! Happy green roofing - - Kevin :)