If you have a skyline of tall buildings I think they fulfil the role of trees in roof garden design: adding interest in the upper-layer of the picture. Therefore I would maintain planting closer to the roof. A simple tip is to group your planting to create greater impact and build simple planting Roof Garden Design Ideas - Gardening - Learning with Experts Please note: You are currently browsing img vegetable roof garden gallery garden design that is 600x450px in size. This image is listed in rooftop vegetable garden design ideas category. Roof Garden Design Ideas Gardening Learning with Experts, 600x450 in 64.80 KB.