We typically think of designing cities and buildings with hardscapes, not landscapes. We tend to construct jungles of asphalt and concrete, barely suitable for even the human animal that built them. These hardscapes typically seem to chomp up a bunch of prime farmland or natural area in favor of boxy buildings. The uses are determined and singular. Our structures are unchanging and unyielding to change. Change and adaptation is a necessity in our society and this should be reflected in our structures and urban form. Rooftop agriculture is one way to break up the norm. It is local, organic, human creativity building farms in the sky.
I personally like the idea because of what it does to a building footprint. I think of the footprint as the amount of land the building stamped out and made unusable for other purposes, other purposes including habitat, agriculture, anything green. What rooftop growing does is take this footprint and lift it up. Land lost becomes land gained.
We started planning the 401 Richmond agricultural installation in April. The building has an acre of roof between two stories but we started with a little 1,700 square foot area. In this small space we have four 4 x 8 beds for vegetables, five 4 x 8 beds with mini food forests, and some carefully placed pots and felt beds.
I can already see the benefits of this little project. It is providing food and habitat for native pollinators, spiders, butterflies and birds. Stormwater runoff is delayed as the plants and soil absorb and slowly release the rainwater. The view from surrounding buildings is substantially better than a normal rooftop. It gets local food onto local plates.
It is not perfect. It is warmer and more windy than the ground level. Shade is sparse or too much and is dependent on how many skyscrapers are being built nearby. There is a constant fear of structural limitations or scratching the roof or not walking quietly enough and disturbing a tenant below. We have a limit of 18” of soil. It is harder to get worms up there. It is hard to get anything up there for that matter.
The crane lift is it’s own story but it brought up 12 gigantic bags of Rooflite soil. This soil is supposed to be lighter because of a unique composition. It doesn’t feel any lighter when you’re shoveling but the composition is unique. They’ve added a lot of rock which I was skeptical of at first but it has dramatically cut down on how much soil blows away and is pretty ideal as far as drainage.
Urban agriculture is still a fairly new experiment, especially on a historic building with structural limitations, but so far this experiment feels successful. The felt beds produced a crop of greens, radishes and are still working on producing some beans, peas and brassicas. I started seeds indoors in April and May so I planted a variety of tomatoes, hot peppers, sweet peppers, eggplants, herbs, celery and squash. The mini food forest boxes have chum trees, dwarf apples, blueberry bushes and strawberries.
As an experiment I would like to see this idea grow. Toronto is a great place for this to happen. The green roof bylaw passed in 2009 requires all new buildings over six stories tall and with more than 2,000 square meters of floor space to have at least 20 per cent green roof. Studies have shown that Toronto has 6,200 hectares that could be made available for agriculture, much of which is on unused rooftops. If converted to small urban farms these roofs could provide real food security. The roof of Ryerson University’s George Vari Engineering and Computing Centre, for example, produced 2 tonnes of produce on a 929 square meter farm in one summer.
We as a species of city builders and city dwellers need a new paradigm. Occasionally we seem to notice the impact we have on surrounding ecosystems but not necessarily consider how the city is an ecosystem itself, with its own systems, species and habitats that we directly impact every day. Rooftop farms and green roofs can help encourage an ecologically healthier city, provide habitat and green space, all while producing local, delicious food in a previously unusable space.
But even if you don’t have a roof space to grow crops, please plant something. It is so easy to grow your own food. It isn’t cost prohibitive. Maybe you won’t grow everything to feed everyone but you can supplement any diet with just a small window space. You don’t have to load your roof with plants. Just use the space you have, the materials you can find, throw some seeds in and give them some love and occasional water.