Posted by Lorna.Doone on 22. December 2009 22:59
Maybe the dead of winter isn't the time when most of us would typically thinking about gardening, but the topic of rooftop gardening was brought up in the month's Popular Science, and I thought it was too interesting to pass up mentioning here. You can read the full article on their web site.
This particular piece by John B. Carnett is a pretty straightforward description of how he is preparing the roof of his home to be an actual garden next spring. I just love this idea, although I think Carnett is ahead of the game in that he actually has flat places on his roof that can be transformed into green spaces more easily than, say, the pitched roofs that many of us have keeping the rain off our heads. Still, the idea of converting rooftops to gardens is becoming more and more popular, not just for homes, but for office buildings, too.
There are some major advantages to "green" roofs, and the ability to harvest a salad from the attic is just one of them. Rooftop gardens also clean the air, create more oxygen, act as insulation, and according to the article can "triple the life span of a roof." If that's not enough of an incentive, check out this list of advantages of rooftop gardening from Canada's CityFarmer.org:
- Increase access to private outdoor green space-at home or at work-within the urban environment
- Support urban food production
- Promote individual, community, and cultural diversity
- Improve air quality and reduce CO2 emissions
- Delay stormwater runoff
- Increase habitat for birds
- Insulate buildings
- Increase the value of buildings for owners and tenants alike
- Create job opportunities in the field of research, design, construction, Iandscaping/gardening, health, and food productio
Converting the rooftop to a garden space does take some special considerations, such as how to properly waterproof the thing so that it doesn't rot away. It turns out that it's not quite as easy as just rolling out some sod and hammering it down with roofer's nails. The weight of the thing also comes into play, as four inches of soil adds up to an additional fifteen to twenty pounds per square foot. So, if a green roof is something that really interests you, you're probably going to need to get an engineer involved.
I thought the author offered a really great recommendation, too. Rather that boxing the whole roof in as one big piece, he installed removable trays so that they wouldn't create an impossible situation should he eventually need to engage in some roof repairs.
Call me a romantic, but one of the things that I love about rooftop gardens, even beyond their environmental benefits and the inherent coolness of the idea, is how amazing they look. Imagine flying over a city where all the skyscrapers looked like this from above.