Protocol of Data collect

For each green roofs, 9 actions...

It takes around 2 hours per roof (depends of the green roof size).

1/ Date + Time + Weather + Project Name

2/Temperature outdoor + height of the roof + location of green area

3/Visual and general observations
3/1/ General coverage
3/2/ Weed coverage + collect of samples for the herbarium
3/3/ Moss coverage

4/ Sketch (drawing) of the vegetation on the roof – position of species + position of buildings + shadow + others stuffs which can explain some data.

Example of planting coverage drawing - Heinz May 2007

5/ Inventory of all the plants species and their abundance (coverage + general information)

6/ 1st Transect: North to South. 20ft. 6 measures/6 quadrat
6/1/ Vegetative coverage
6/2/ Three measures of the soil thickness (at 0ft, 8ft and 16ft)
6/3/ Take photos of the 6 quadrants

Same for the second transect (E>W), the third, etc…

Example of one quadrant

7/ Soil Samples
7/1/ Collect some samples of soil in 7 – 8 locations of the roof. Feel the collect bag.
7/2/ Open the media to see the roots + drainage layer + quality of the soil. Do it twice and choose different plants to see different types of roots. Take photos

8/ Collect insects (flyers + soil organisms)

9/ Take photos of the roof (do it during all the analysis)

Trip description : more than 6000 milles and 46 Green Roofs!

You can notice that I visited green roofs of different climates : From the 4 to the 7...

June 27th - World Trade Center - Boston

This green roof is located near Boston waterfront so oceanic winds are here very important. Roofscapes used an important wind protection plan: hidden ballasts and pre-vegetated mats to establish the vegetated coverage.

The media is quite deep (5 inches) but as you can see in the photos the Sedums coverage is excellent. As usual, I notice few clovers patches. A interesting weed specie colonize some roof area. I'm still trying to identified it but the fruits are very unusual and aesthetic. This is not a real problem for the roof itself because Sedums are very healthy and their coverage is really dense (around 100%).

June 26th - Four Season Hotel - Boston

This 8500 sf, un-irrigated green roof looks very fine!
The only 3 inches of soil with a plastic drainage sheet allow different Sedums species to grow well (Especially S. Sieboldii, S. Cauticola..).
Here the planting design is based on different colorful lines; which are still perfectly visible after 4 years. A yellow/white and a blue/gray one. Sedums flowers (Sexangulare, Album) and leaves (Cauticola, Sieboldii, ..) give to this roof a very interesting and unusual stripes aspect. I like it!


To preserve this design and to prevent the high weed pressure (mostly clovers), a relatively good level of maintenance is required. But without any water and with a shallow media, the coverage is excellent and people from the surrounded (Hotel clients) can admire this original roof!
Much more nicer than a conventional one, isn't it?

June 3th, Heintz, Pittsburg, Dynamic Design?

I want to introduce an interesting point: the seasonal design.

My first green roof visit of Heinz was on May 5^th. At this time, plants like Phlox, Festuca, or Allium Scoenoprasum were the most attractive plants. They gave to the roof its attraction.

But it’s nothing to compare with the June roof. At this time, Tradescantia, Chrysanthemum or Anthemis bloom like crazy. As you can see in these two photos taken at the same place below (one was taken in May, the other one in June), the difference is incredible…

This is a dynamic design! Good job Charlie!

May 30th, Asbury Woods Nature Center - Erie PA - a nice curved roof in the forest

Photos are speaking... Just beautiful, very surprising for a two year old roof. I think that the weather effect is the main reason for this exceptional coverage. All the species look perfect.
This roof was planted using two methods. In the flat part, cuttings of Sedums species and Talinum and Allium seeds are growing well, especially S. Sexangulare and S. Spurium.
For the sloped part (max 7:12), the plug method was used. And it's perfect. I didn't notice too much erosion because of the strong roots system and the good design.
This roof is 4700 sf covered with 4 inches of minerals in a gridlike matting, designed by Roofscapes.


From far, this roof looks like the green roof on the Life Expression Wellness Center (see April comment) but if we look closer, the diversity here, at Asbury Woods, is more impressive. Even the usually tiny S. Sieboldii is wonderful.
As a Nature Center, many students come there and look at the roof.
The Director (Brian Winslow) wants to improve the green roof education and he will plant green roof plants at the building entrance, near another curved green roof under construction.

May 25th, City Hall - A movie from this wonderful piece of green art in the middle of Chicago

May 25th - City Hall Chicago - INCREDIBLE!

It's difficult to begin with a roof like this one...! It's just amazing to see how it was possible to design a green roof like that on an antique building as City Hall.
I spent the morning with Kevin Carroll. Like the green roof, this guy is incredible! I have never seen someone so good in botanic. Especially native plants of Illinois. I learned a lot of different plants' names. There are probably more than 100 different species on the roof.

Nice roof! Thank you Kevin...

Every year they try native species (planted by plugs by a local nursery). This roof is like an experimental field. I think that all the green roofers HAVE to go there before building a green roof. It's the perfect example of what we want on all the roofs (if the building is engineered for that...).
Describing this roof will take me a book, so I have decided to put in more photos because sometimes pictures speak more than text (especially my 'french-english).
I just want to say that the idea of using Polystyrene to build some kind of relief is just smart and really aesthetic. It gives to the roof an natural style. Especially with all those native plants. Some plants were in bloom, such as the Columbine, the Pusatilla Posque Flower, the Amorpha Canescens, the Baptista Australis, etc..

About the maintenance, you have to know that it's very very high. I mean, one worker (who knows the plants well), is on the roof from April to October. His main task is hand-weeding and planting some new plants (annuals a bit in early June and new natives).
More surprising, a beekeeper was there when I visited the roof. He told me that Bees love the roof and the honey is very good there (because of the natives..)

The Beekeeper (top right), Kevin and SanDiego the worker (first plan).

Unfortunately, it's difficult for the public to access that roof because of security reasons (it was forbidden to build a guardrail because of the building's historical interest). But the roof is visible from plenty of surrounding windows and sometimes people visit it.

A impressive Dragonfly, there were to many!

To conclude, I really appreciate to answer your questions, if someone reads this comment, because I have much things to tell about this piece of green ART!

May 21st , Lincoln Park Zoo - Chicago

This roof is a sub irrigated one with 8 inches of media + drainage. The plants' diversity is its first characteristic because I found more than 20 different species: Thymus (photo underneath), Festuca, Dianthus, Sedums (of course! But some an unsual varieties: Sedum speotabile 'Robustrum'), etc...

Thymus serpyllum 'Coccineum'

You can understand that I was very happy to see that! Moreover the weed pressure was low. Even if patches of gloves were perfectly included into the wind protection net (it was not destroyed by the sun at all...).


I also noticed an important colonization of Euphorbia cypariasias ' Fens Ruby'. They were very dominant here. In fact in this season, a lots of species bloom like: Armeria Maritima (photo underneath) or Hemenocallis 'Stella D'Oro' (photo underneath).

Armeria Maritima

Hemenocallis 'Stella D'Oro'

I also see an interesting point: in the entire shadow part of the roof, grasses were healthy but not really the other species.
The difficulty for maintenance will be to kill the gloves patches because they are very stong into the net. Unfortunately spray herbicide is the best solution..

May 21st, Peggy Notebeart Museum - Chicago

This four years green roof is composed of different thicknesses of media. From 5 inches to 18 inches.
The part is planted with a nice tree, a Quercus imbricaria. It was very healthy when I saw it today. As you can see on the photo above, this tree gives to the roof a really interesting shape and structure. I like it!

As the Sanitation District green roof, in Cincinnati, this roof has an educational purpose. A lot of children from Chicago's schools come and learn about green roofs.
I was very happy to see a wet area with a pond and a water feature. Like that, Iris can easily grow and gives an original touch to the roof.

Unfortunately, the maintenance is very low and plenty of weeds live there. In my opinion this is not so bad. The roof has a perfect biodiversity and it's perfectly included into the surrounded landscape. From an engineering point of view, weeds can damage roof layers and the building structure (weeds can be very aggressive and have strong roots). So, a minimum of maintenance is required.

May 15th, Kansas City Library

Another nice and accesible green roof. Like the Heintz's green roof in Pittsburg, it is located in a very dense area at the fifth floor of the library.
People can easily enjoy the downtown view, play giant-check and be relax around the diversified vegetation.

During my survey I noticed many different kind of plants, from the cactus (Opuntia polyacantha), to the Monarda fistulosa in the wet zone. This area was specially design to receive a water feature and to stay humid all the year round. Of course, the plant selection is adapted to this situation.

I really like the contrast creates in this zone.
As you can see on the photo underneath, contrast beetwen the cactus, symbol of dry vegetation and the humid area garden wall.

Technologically this roof is a 4000sf vegetated and can be consider as an intensive one. With 6 to 18 inches of thick (for the trees) , the media is irrigated by capillary irrigation and flood irrigation.
The vegetation around looks very healthly and some flowers are already appear, like Allium Rosenbachianum or Zizia Aurea.
I also notice a difference between the grass in the tree planter (18 inches + flood irrigation) and the ones in the roof (6 inches + capillary).
In the planter the density of grass population was higher. Also grasses in planter were more green. In my opinion the difference is due to the thickness of media. Carex and bouteloua love deeper soil!

In my photos don't be surprize by the grass colour and size. They were just mow few days ago. Also, during spring they will become green and very tall (1 m). During summer, the colour will change to something more yellow, at this time, the difference between the species will be interesting. During Fall, the red and yellow colour will give to the roof a wonderful apearance.

Here, the green roof needs a really good maintenance because of the public. So, the weed pressure is very low.

What about our friends the buds? There were also happy there and I saw my first green-roof butterfly!

May 14th, Oaklyn Library - Evansville (Indiana) - A roof-meadow includes into the landscape

This large green roof (18000 sf) is the first one I saw without any Sedums.
Actually, a plant palette of perenials grass and meadow plants covers this innovative design building.
Here, the idea is to include the building and the roof into the wild surrounded landscape.
In my opinion the result is impressive because it was difficult to locate the exact limitation between the roof and the meadow. Can you see it in the photo underneath?

About the roof itself:

Roofscapes selected a Roofmeadow® Type IV intensive green roof assembly. It includes a base layer of granular drainage material with an upper layer of growing media.
The total depth of this intensive green roof system is 14 inches or 35 cm.
The main grass, Andropogon scoparious, and the other plants, use the drainage layer as a water stock.
In the next photo you can see the nice flower of the Phlox drummondii:

I was surprise by the perfect coverage of this roof, the planting method (seeding + plugging) gives a really good result after 3 years.
Of course, you can imagine how insects like this area... Especially ladybird and a red specie of wasp.


The maintenance is also very low because the roof is just mowed twice a year.

Finally, some volunteers (like Vicia Cracca, first plan of the photo underneath) were there because of the wild area 's proximity. That gives to this roof a wild and natural style, which I love.

May 3th, Heintz - Pittsburg, a very urban green roof

Covering 12,000 square feet or slightly more than ¼ of an acre, this extensive green roof uses a two layer Roofmeadow® Type III assembly. There are three inches of growth media over two inches of engineered drainage media. The five inch depth enhances the drought resistance of the green roof ecosystem.

My first impression was: "I can belive to find this diversity of plants on a 14 stories building in the most densely populated business district of Pittsburg."

People from Heintz's office have a direct view on it, that's why they maintain it twice a year (manual weeding).

My transect analysis tells me the true. More than 20 species lives here! Some of them were very attractive even if the majority of the plants's roof were still dormant. Let's see those wonderful Phlox Subulata, Potentilla Verna, Allium Tuberosum or Festuca Glauca. Incredible!


Here, Sedum species really cover the entire roof and the accent plants give it a colorful sensation. I didn't notice any invasion by one particular specie; It was a balanced competition.


But how it's possible to obtain these diversity?
One solution is probably the media. When I opened a part of it, I was surprise to see how the roots penetrate the layer to take water from the drainage layer. As you can see on the photo, they love that!


Finally, some insects like this nice ladybird were happy to live here.



Vive la biodiversité!

April 19th, Life Expression Green Roof

A wonderful curved green RoofThis building includes 6000sf of green roof. The owners, Ms and Mr Gallager were very attracted by the concept of 'green building', which includes air circulation, sun orientation, daylighting and of course the green roof. The owner was very happy to show me his roof and together, with a student of Penn State, we spend few hours over it. The engineering challenge for Roofscapes was to build on the slopes, 3:12 to 7:12! Now plants' roots hold perfectly the media, also for the higher slope.

Now, Let's see the plants description. As the fencing Academy project, this roof is considered as mature, the coverage is almost 90% even in early spring. During my survey, no plants were blooming but it was enough to seriously analyzed it.

I was surprized by the Sedums location.
At the borders (top and bottom), the diversity was incredible : S.Acre, S. Sarmentosum, S. Reflexum, S. Spurium, S. Floriferum and S. Album. Also, some patch of moss was observed but only 5% of the coverage for those edge parts.
To compare with the low diversity of the middle of the slopes. There, S. Spurium and S. Floriferum was the only plants, sometimes a patch of S.Album coral carpet.
A soil were collected to help find an answer to those observations.

The owner often takes care of his roof by fertilize it and weeding it, so that the weed pressure was extremely low (less that 3%).

As a personal point of view, this roof proves that ecology and building are compatible. Like in Europe (especially in Switzerland), this building in totally integrated into his environment, not only in terms of energy but also in terms of positive visual impact. The surrounded landscape and the roof formed a homogeneous view, pleasant for visitors and neighboring.