|I'd like to know when to spray apple trees with oil spray to kill bug eggs and how to prevent apple scab and what to spray them with.|
|Horticultural oil, sometimes called dormant sprays, smother overwintering scale insects and insect eggs. They're usually applied while the tree is dormant in the winter. Choose a calm day when the temperature is above 40F and be sure to thoroughly spray all sides of the branches and all areas of the trunk.
Apple scab is a fungus that overwinters on dead apple leaves or fruit on the ground. Be sure to pick up and destroy any plant material left on the ground in the fall, to reduce the chance ofinfection in the spring. The key to controlling scab is to apply fungicides early in the season to protect new growth. Bordeaux (lime sulfur) should be applied as soon as the buds break, and reapplied until the leaves are fully expanded. Spray at prepink, pink, and after the petals have fallen. More detailed information will be included in the directions of the fungicide you purchase.