This never seems to run out, as there is a large surface area on the roof to collect water. Back to top of list. Controlling Pests and Diseases. Although the aim is to create a haven for wildlife, it is sometimes necessary to interfere with the balance if certain species become too dominant. After all, this is an urban environment and some management needs to be involved.
Resistant plant strains.
This is all very well but such manipulation of the genetic structure has its drawbacks. Quite often the selection of genes for particular characteristics are traded against those genes which give the plant a natural resistance to pests and diseases. Hybrid varieties are particularly vulnerable. You will therefore often find that older varieties of plants can be more successful in your garden. These can be obtained from good quality garden centres or nurseries.