The most effective method is the one matched to how the pest feeds: chewing insects, sucking insects, and boring insects each call for a different treatment, so identifying the pest comes first. A healthy tree underpins all three approaches, since a strong tree is less of a target.

How can the type of pest be identified?

By the damage it leaves. Chewing insects leave bite marks and stripped leaves, sucking insects leave scaly formations on branches and a sticky residue called honeydew, and boring insects leave small mounds of sawdust at the base along with entry and exit holes in the bark.

How are chewing insects controlled?

With a spray that kills the caterpillars and beetles feeding on the leaves. For a tree losing foliage to chewing insects, spraying Garden Insect Spray with Spinosad gives an option approved for organic gardening that resists breakdown in sunlight and needs reapplying only every 3 to 4 weeks.

How are sucking insects controlled?

By smothering them where they feed. Coating insects such as scale, mites, and aphids in a film of oil, Horticultural Oil Insect Spray can be used year round on indoor and outdoor insects.

How are boring insects controlled?

With a systemic treatment, ideally before borers settle in, since control becomes extremely difficult once they are inside. To protect a tree through the growing season, Once A Year Insecticidal Drench w/Merit is watered onto the roots in the fall or early spring.

Frequently Asked Questions

Can keeping a tree healthy prevent pests?

Partly. Healthier trees are less likely to become infested, which makes proper watering, mulching, fertilization, and pruning part of pest control.

When should a tree be pruned to avoid attracting pests?

In late fall or winter, so open pruning wounds don't draw insects during the growing season.

What if a tree is too large to spray?

A trunk injection or a soil drench reaches the whole tree instead. An injection spreads through the tree in about 72 hours, while a drench takes about 3 weeks and then protects the tree for a full year.

Do insect traps help?

They can. Traps reduce the local population of the insect attacking the tree, which works alongside a treatment rather than replacing it.