Intensive roof planting
Intensive plantings offer a wide range of design options, including the creation of a roof garden. Sunbathing areas can be created, and trees can even be planted.(kopie 1)
As long as the vegetation layer is deep enough, and sufficient water and nutrients are provided, conditions for plant growth on the roof can be virtually as good as at ground level. Certain factors do need to be given consideration, e.g. the stability of trees and shrubs or potential negative influences from the building, such as heat radiated from facades. The planning of an intensive planting, and in particular the choice of appropriate plants, requires specialist knowledge.
(kopie 2)
To decide on the depth of the vegetation layer, the following simple formula can be used for trees and shrubs: "Growth height/10 = substrate depth". Lawns and groundcover plants need at least 20 cm of substrate. Despite the large water capacity of the substrates, intensive plantings in general and lawns in particularly must be regularly watered during dry periods. With roof gardens, just as with any domestic garden, there is a direct relationship between the quality of care and maintenance and the condition of the vegetation. In view of the large variety of intensive planting options, it is advisable to establish an individual maintenance programme.
The amount of maintenance required is considerably greater than with extensive plantings. As a guide, consider the maintenance involved with a comparable ground-level garden.