We apply dormant season spray to deciduous (leaf losing) trees and shrubs in the winter to help prevent insect pests and diseases the rest of the year.
Experts often recommend a combination spray consisting of horticultural oil mixed with earth friendly copper or Bordeaux.
The oil serves to suffocate insects and mites along with their over wintering eggs. Copper helps prevent fungal disease such as powdery mildew, black spot and rust on roses, and peach leaf curl and shot hole fungus on stone fruits.
In Santa Barbara we usually spray our roses with oil/lime-sulfur immediately after pruning.
At least two sprayings for fruit trees is recommended between December, when they lose their leaves, and February, before the buds break.
- Read product labels carefully.
- Clean ground of all old leaves etc. prior to spraying.
- Apply spray thoroughly. Cover all branches, crotches and trunks as well as the ground under the drip line of the plant.
- Do not apply lime sulfur to apricot trees.