In the center of Columbus, American Electric Power is taking steps to help protect the environment, reduce waste of natural resources, and put Columbus on the map with other forward thinking places around the world: Stuttgart, Chicago, Pittsburgh, Northern Kentucky, and Chardon, Ohio.
Why a Green Roof?
An extensive green roof stores 75% of rainwater in plants and the soil layer. Twenty-five percent percolates thr
ough the vegetation after several hours and releases into storm drains. A green roof reduces peak flow of water during intense downpours; concrete and hard surfaces sluice the water into the drainage systems. The 15,988 square foot AEP Green Roof captures the first inch of rainfall for the building's grey water system (used to flush toilets). Additionally, only recycled water is used for irrigation on the roof; the water is stored in a tank on top of the building.
What are the other benefits?
Thermal insulation. According to Roofscapes Inc., a green roof allows new construction to be designed with smaller HVAC systems, requiring less maintenance. By shielding the surface from harmful UV rays, a green roof reduces the daily expansion/contraction of the roof materials caused by temperature fluctuation. A green roof has the potential to reduce the urban "heat island" effect by adding moisture to the atmosphere, and a roof with 6 inches of sod reduces noise by 50 decibels. Last, but certainly not least, a roof garden provides habitat for birds and insects, as well as native grasses, wildflowers, and endangered indigenous plants.
How is a roof garden different?
Being on top of a building, these landscaping projects require special planning and materials. You don't just dump 6 to 12 inches of heavy topsoil on a roof. An example of growing medium used is a mixture of coarse sand, forest humus, red lava, and other light materials. Depths on the AEP garden are 6, 8, and 12 inches, so the plant materials chosen are those with shallow root systems, such as sedums, small grasses, Dianthus, Saxifraga, Potentilla, and others. The first planting consisted 
of 24,000 plugs of more than 60 varieties. The deeper soil areas are located over support columns and I-beams, and are planted with grasses and some herbs.
The AEP Rooftop Garden is a valuable project for learning about new ways to conserve energy and natural resources. The garden isn't yet open to the public and, in its first year, is not lush with growth. But strolling over the terracotta red and tan walkway of paver tiles made from recycled automobile tires, the view of the city is magnificent, and will only get better!
Posted by doccat5 (from Fredericksburg, VA) on February 2, 2008 at 3:11 AM:This is a fascinating article. I've noticed more and more information being published about these type of roof gardens, especially in cities with very positive results. It's a wonderful change to see. Thanks for sharing :)
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Posted by svplantingfool (from South Venice, FL) on February 2, 2008 at 9:34 AM:
The first thing I thought of when I read the title was sod roofs!
Thanks for a very interesting article, I hope you'll be able to feature more green roofs in future articles.
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Posted by tonileland (from Nashport, OH) on February 2, 2008 at 10:04 AM:
Thanks!
I just learned yesterday of a very large green roof somewhere out West. I plan to research that and do some followup articles.
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Posted by LouC (from Desoto, TX) on February 2, 2008 at 10:46 AM:
So glad to have your expertise here on Dave's Garden. All of our harrassing you was in good fun and now we have you for our own. Appreciate the information and presented where it is easily understood.
Christi
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Posted by Dea (from Frederick, MD) on February 2, 2008 at 10:48 AM:
I'd love to see one in full bloom :)
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Posted by darius (from Appalachian Mtns, VA) on February 2, 2008 at 2:50 PM:
Thanks! Seems like there was some discussion on green roofs in the Sustainable Alternatives forum but your article will introduce green roofs to a wider audience.
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Posted by Islandshari (from Kwajalein
(Marshall Islands)) on February 2, 2008 at 7:30 PM:
Wonderful information Toni! The more folks that are made aware of this potential, the better! Thanks for bringing it to our attention.
Yokwe,
Shari
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Posted by roybird (from Santa Fe, NM) on February 2, 2008 at 7:49 PM:
Thanks. I'd like to know more about green roofs. I'd like to see more pictures of them.
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Posted by frostweed (from Arlington, TX) on February 2, 2008 at 8:55 PM:
There are also some green roofs in Austin Texas, one is the roof of a Starbucks coffee shop.
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Posted by grampapa (from Wheatfield, NY) on February 2, 2008 at 11:05 PM:
Very cool!
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Posted by kbaumle (from Northwest, OH) on February 4, 2008 at 12:52 PM:
Toni, I'm so glad you wrote about this and had pictures! THANK YOU!
My mom and I were at the Master Gardeners Conference as well and didn't get to do this tour. We did get to see Tracy DiSabato-Aust's garden though, as well as Inniswood and Park of Roses. We had a great time. I wrote several entries on my blog about what we did while attending the conference. Here are the links to the entries:
[HYPERLINK@ourlittleacre.blogspot.com]
[HYPERLINK@ourlittleacre.blogspot.com]
[HYPERLINK@ourlittleacre.blogspot.com]
[HYPERLINK@ourlittleacre.blogspot.com]
[HYPERLINK@ourlittleacre.blogspot.com]
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Posted by tonileland (from Nashport, OH) on February 4, 2008 at 4:03 PM:
Kylee, how cool!! We probably passed each other a dozen times that weekend!
I took pictures of the private home garden (can't remember who), the Topiary Garden (in the last articles I wrote), and the Labyrinth at the campus. I think I snapped about 147 pics that day. Loved every minute!
I'm thinking for this year, any of us who go should all share our photos. It was impossible to be on three tours at once! LOL
Thanks for your nice note.
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Posted by Fitsy (from Hayesville, NC) on February 4, 2008 at 5:18 PM:
I am happy to see this article. I hope we have
more and more green roofs.
Fitsy
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Posted by kbaumle (from Northwest, OH) on February 4, 2008 at 11:13 PM:
Toni, yes, I'm sure we did see each other at least once! Is Kelton House the one you were thinking of? Did you read that I crashed a wedding reception there? LOL. With 'permission' of course. ;-)
Did you find the cat at the topiary garden?
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Posted by tonileland (from Nashport, OH) on February 5, 2008 at 4:08 PM:
I do remember the wedding at Kelton House...we ALL managed to stumble into it, gawk, then shuffle backwards most embarrassed.
Cat in the topiary? I missed that one. Sigh. so much to see.
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Posted by kbaumle (from Northwest, OH) on February 5, 2008 at 5:40 PM:
I spoke with the employee in the gift shop and she told me that there was a cat placed that was not in the original painting. It took me two tries to find it. It's sitting in the lap of a little girl.
You're right...soooooo very much to see!
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