The Three Types of Garden Roofs
In-situ Green Roof
Every component of the garden roof is assembled layer-by-layer, directly on top of the roofing system for a uniform look. There are two types of in-situ green roofs: they can be "intensive" or "extensive" referring to the amount of effort/labor required for them. Traditional roof gardens require a substantial soil depth to grow large plants or conventional lawns, are considered "intensive" because they require irrigation, feeding, and other maintenance. "Extensive" green roofs, by contrast, are nearly self-sustaining and require little intervention. It’s not uncommon to use the toughest native plants for extensive in-situ roofs.
Modular Green Roof System
Pre-planted modular trays, or containers are positioned on top of the roof. This allows for repositioning and easy maintenance, so that in case any plants don’t take to the rooftop environment, they’ll be easy to switch out for a hardier species. Sometimes, people will even take some of the plants inside or to a greenhouse for the winter.
Pre-Cultivated Vegetation Blankets
Another option for green roofing that is easy to install, but harder to maintain. To install, the rolled vegetation blankets are simply unrolled on a prepared roofing surface. These will need significant maintenance at first to ensure that the plants establish themselves.