How To

It’s nearly impossible to summarize in a general discussion the multiplicity of diseases and insects that affect shrubs. Some species are virtually disease free while others are magnets for any number of pests. Before planting some shrub you fell in love with on a national gardening show, ask a local nursery professional if it’s a good choice for your area.

Many common fungus diseases, such as black spot, powdery mildew, rust, and leaf spot can be prevented and controlled with a regular fungicide treatment program. These treatments should begin before disease conditions exist (heat and humidity, for example), and continue faithfully until those conditions no longer are present.

Insect pests common to a variety of shrubs include aphids, whiteflies, scale, mealybugs, leafminers, leafhoppers, and slugs and snails. Insect can not only do damage directly, by feeding on leaves and sucking juices, but they can also be vectors (carriers) of plant diseases, or create injuries that allow diseases easier entry into plant tissue. After identifying the insect pests, control them with insecticidal soap, neem oil, pyrethrin, or other insect spray.

There are multiple disease and insects that can negatively affect trees. The type and amount depend on the tree type and the care that it is receiving.

It is not practical to treat fungus diseases within full-grown trees due to their maturity and size. Younger tree diseases can be prevented and controlled though by using a regular fungicide treatment.

Insect pests that are common to shrubs include aphids, whiteflies, scale, leaf miners, leafhoppers, and a host of borers. Insect pests can damage shrubs both directly and they can carry disease within the plants system itself. Control these insects using an insecticidal soap, neem oil, pyrethrin, or other insect sprays. Be sure the spray will not damage your tree any further.