Spraying fruit trees
Dormant oil should be applied to fruit trees in early spring while they are dormant but just prior to bud swell. A dormant oil spray one week before bud break is most effective. The entire tree should be covered with a layer of the oil.
Dormant oil is a highly refined petroleum oil used primarily to control scale insects and the overwintering eggs of red spider mites and aphids. It is diluted with water prior to spraying. The oil coating suffocates these pests as well as their eggs. Insects cannot become resistant to it.
Spraying of dormant oil should occur on a clear day when the temperatures are expected to remain over 50 degrees F. for at least twenty-four hours. The ideal temperatures for application is between 40 and 70 degrees F. in order to get the oil to spread out over the tree and cover all crooks and crevices. Try to avoid applying dormant oil when severe freezing trends are expected in the 3-4 days following application.
Pruning fruit trees
Prune fruit trees any time during January – March before flowering begins. Trees can be pruned after budbreak with no harm to the tree if you happen to be late in getting started.
Fertilizing fruit trees
Fertilization should occur immediately before bloom or leaf sprout occurs which is usually in March. A good general recommendation for rate to use per tree is one pound of fertilizer per inch trunk diameter. Use 21-0-0 or ammonium sulfate if your soil pH is above 7.0. A complete fertilizer such as 15-5-10 can be used if your soil pH is below 7.0 If additional applications are made, use only nitrogen fertilizer. Trees should make 18-24-36″ of terminal growth annually.
Fertilizer scattered evenly over the surface of the ground above the root system is just as effective for plant maintenance as is root feeding. Scatter the fertilizer starting about six inches away from the base of shrubs or about 1 foot from the trunk of a tree and extending to a short distance beyond the ends of the branches. The fertilizer can be lightly raked or scratched into the mulch or soil and then watered in.