Garden on the roof

Photo credit: Marianas Variety

Turn a roof into a garden

With the summer months on the way and the high cost of utilities, this could be a good time to consider a rooftop garden for your home or office.

With good planning, sturdy containers and the right plants, you could transform your ordinary roof top to a garden with small plants, moss, fresh herbs, vegetables, or fruits that is mostly low on maintenance and could save you lots on energy costs.

Green roofs are of three types: ornamental roof gardens requiring high maintenance, roofs with shallower soil and narrower range of planting, while the third type is made up of Sedums, mosses and whatever else establishes itself naturally.

How it works

A layer of soil is placed over a waterproof roofing material, with raised sides to prevent soil washing into drains when it rains. The soil is planted with vegetation which can withstand extremes of hot, cold, dampness and drying out.

Cooling happens not just because of shading the roof surface, but also because up to 60% of all rain is retained on the roof in the soil and as it evaporates, it acts as an air conditioner, cooling the entire surface.

Plants themselves also lose water by transpiration, cooling their leaves down. Water loss is higher than at ground level because wind speeds are greater.

Read the full article: Marianas Variety

Published by

Willem Van Cotthem

Honorary Professor of Botany, University of Ghent (Belgium). Scientific Consultant for Desertification and Sustainable Development.