BURLINGTON, Vt. -
If you have a flat roof, you are probably wasting a lot of garden space. Look at what they did on this flat roof. You can grow all kinds of vegetables and fruits and herbs on your roof! It's amazing.
The first thing, of course, is to have a sturdy roof. You don't want to just pot up all of these pots on the roof if you are not sure about the structure underneath. But once you've evaluated your roof and you know that it's strong enough to hold the pots and containers, then you want to get lighter weight containers. These smart pots are made out of a polypropylene fabric that will actually breathe a little bit and they are not so heavy. When you put all of that soil in there the pot is not adding that much more weight.
Now you can also get really experimental with your rooftop garden. In this garden they are actually growing perennials such as hardy kiwis, grapes and currants on the roof. They are not moving them off the roof but leaving them through the winter. With the snow cover for protection they are actually surviving.
They also have some automatic watering systems working. This is a huge production of 600 pots they have here. Even with having a drip irrigation system around your roof, you are going to have to water a couple of times a day during the summer. It's hot on the roof, which is great for growing, but they need water.
Having your drip irrigation system on a timer is a great way to do that and to add fertilizer regularly. You have a small soil mass, so you are going to have to put a lot of fertilizer on there pots every couple of weeks to really keep the plants going strong.