Newby seeks roof top gardening advice
Last summer I built an 8' x 12' deck on the flat roof of my house in the boston area. This year, I want to surround (fence in) the deck with a series of containers for growing vegetables, herbs and some decorative plants. I anticipate tha the containers will be between 22" and 24" square on the inside with various depths dependent on use. The floor of the containers will have holes to allow drainage into a water reservoir below (plastic tub), a filler tube and for wicking of water into the soil above. The containers will custom built for attractiveness and will include legs to bring them to waist level for ease of access. With these remarks in view, I would appreciate comments on the following issues.
Recommend a good soil mix that will work well in a self watering environment and be light in weight. With respect to the weight, I'm hoping there exists a mix that will not exceed 64+ pounds per cubic foot (the density of pure water) when completely saturated (assumed worst case). There is no need to comment on the capacity of the roof as I am a retired structural engineer and will take care to address this issue. I'm more concerned about the weight that I will have to haul up to the roof.
With regard to the self watering system, should I use a column(s) of soil down into the water reservoir or rope for wicking. Is there a rule of thumb as to the area of wick to total area of the container which in my case will be close to four square feet. How about impact of soil depth. In general, do you think self watering is appropriate for my situation.
Can I be confident that 2' x 2' containers will be large enough to grow the largest tomato varieties (say beef steak or mortgage lifter). How deep for herbs, peppers, carrots, lettuce and flowers.
Note that I am a beginner in all this and will have many more questions as I move through this project. Would you recommend that I start a new thread for additional questions or just continue with this one.
Thanks for your attention.