Ask the Master Gardeners of Cornell Cooperative Extension
Q: My fruit trees are ruined every year by insects. When is the best time to spray?
A: In the Northeast, it seems difficult to grow most fruit trees without insect pests affecting the harvest to some degree. The method of handling insect pest problems on fruit trees in the home landscape largely depends upon how the gardener feels about pesticide use.
A traditional and decades-old program of fruit tree pest control would begin in late winter/early spring with a scheduled series of what are called â€œcover sprays.â€
In addition to the early use of dormant oil to control the overwintering stages of certain insects, the main spray mix used in the cover spray program has been known as â€œthe multipurpose mix.â€ It typically controlled both insect and disease pests, using a specific recipe that one could mix oneself or that the gardener purchased premixed.
The individually scheduled cover spray would be timed to the development of the vegetative parts of the tree from the dormant stage through various stages of bud development and beyond as needed.
Additional pesticides might be added as required through the growing season in order to handle specific pests.
In recent decades, as concern over the environment has continued to grow, many gardeners have expressed either less tolerance or zero tolerance regarding the use of traditional pesticides for the control of fruit tree pests.
A preference for organic methods that employ the least toxic means of pest control has been the goal of more and more gardeners.
This approach requires diligent monitoring and identification of specific problems and their potential impact before a least toxic or â€œearth friendlyâ€ method of control is chosen.
Methods of control other than the application of pesticides may also be employed wherever they are useful. Tolerance for a certain amount of pest injury may also be important regarding an organic approach to pest problems on fruit trees.
For more specific guidelines concerning insect and disease pests on fruit trees, contact the Westchester office of Cornell Cooperative Extension weekdays 9 a.m. to noon at 914-285-4640.
â€” Jerry Giordano, senior extension horticulturist and educator, Cornell Cooperative Extension of Westchester