Roof Garden Soil Depth

Proper soil selection is critical to the long term benefits of the living roof.

Roof garden soil depth.

If you re considering a rooftop garden there are a couple of directions you could go in. Once you are set up rooftop gardening is similar to container gardening. The targeted saturated weight of roof top growing media should be 48 65 lb ft 3 3 4 kg m 3. The following are some of the characteristics of the soil for the green roof.

Stable structure for anchorage of plants root systems. B extensive medium depth roof garden system a medium depth planting system soil depth of 4 to 8 where recommended plants include sedums herbs grasses and other vegetation which can grow in this depth of media. It supports the growth of the plants by providing the basic nutrients. Fully planted green roofs where the roof is covered with soil and the plants are in the ground make great environmental sense but they are too difficult for homeowners to undertake on their own.

Soil s saturated weight can reach 120 lb ft 3 7 5 kg m 3 which is far too high for roof gardening. It depends on what you want to grow but generally speaking a depth of 20 25 cm 8 10 inches suffices to grow many vegetables and herbes but do investigate if your roof supports such a weight because a rooftop garden can become very heavy when it s soaked with water.