Aphids overwinter as eggs near buds. Use oil alone or with an insecticide.
Fruit
Pear psylla eggs are laid near buds in early spring. If this was a problem last year, apply oil twice, spaced about 7 days apart.
For fire blight, apply copper to apple/pear between swollen bud and green tip stages. It is OK to mix with 2% oil for the insect treatment.
Peach leaf curl is only prevented by applying copper in spring, when green leaf tips emerge. Infections occur during cool, wet springs. The foliage becomes...
Brown mites overwinter as eggs in protected sites on trees (unlike spider mites, which overwinter on the ground).
