Introduction

Most plant problem symptoms are easy to see. A bonsai may wilt, become discoloured or fail to bloom or even fail to come into leaf at all. What causes this unforeseen happening? It is either because of your failure to water or maybe a delicate tree has been exposed to harsh weather. If neither of these, it is most likely to be some form of pest or disease.

PESTS: Creatures that cause damage to cultivated plants, the largest group of which are the insects. They feed in different ways – by sap-sucking, leaf-mining, defoliating, or tunnelling through stems. Some pests damage plants by spreading viral or fungal diseases. Others coat plants with a sugary excrement that encourages the growth of sooty moulds.

DISEASES: Pathological conditions caused by other organisms, such as bacteria, fungi or viruses. Microscopic organisms spread via a carrier, such as aphids. The pathogen is often visible as a discolouration or rusts.