But unfortunately spring and early summer is a time when fruit trees need to be protected from several insect and disease problems that can affect them at that time of year. For this reason, sanitation beneath and around your fruit trees is very important. Collect and discard or burn all debris from the tree, including leaves and fruit each year. Also prune out and destroy all dead or diseased branches and twigs each spring. Fruit trees should also receive an application of dormant oil spray before they begin to bud out.
Dormant oil is used to control or suppress scale and spider mites on apple and pear trees.
Lime-sulphur is used for the same purpose on plum, peach, apricot and cherry. It will also help control peach leaf curl and plum pocket. To be successful with any spray application, the spray must be applied at the right time with thorough coverage of the tree. Dormant oil and lime-sulphur both must be sprayed on the tree while it is still dormant, before any new shoots or flowers begin to appear. To make the job easier and to ensure adequate coverage, thin out excessive growth by removing all dead and weak wood.