How to Manage Pests

Almost every plant has one or more aphid species that occasionally feeds on it, but low to moderate numbers of aphids are usually not damaging in gardens or on landscape trees. Although aphids can curl leaves and produce sticky honeydew, they rarely kill plants and can often be washed off with water. When aphid numbers get high, natural enemies frequently feed on them, eliminating the need for pesticides. Insecticidal soaps and oils are less toxic pesticides that can be used when treatment is necessary.

• Aphids like lush new growth. Don't over fertilize. Use organic fertilizers or slow-release products.
• Aphids build up on flowering plums, roses, tulip trees, crape myrtles, apples, and many vegetables. Expect aphids when you grow these plants.
• Ants protect aphids from their natural enemies. Keep ants off plants to get more benefit from these beneficial insects.

• Prune out infested leaves and stems.
• Knock aphid populations off plants by shaking or spraying with a strong stream of water.
• Protect seedlings with covers or aluminum soil mulches.
• Wait for hot weather; most aphids are heat-intolerant and will be gone by mid-June.

• Lady beetles, both adults and larvae.
• Lacewings.
• Syrphid fly larvae.
• Soldier beetles.
• Parasitic mini-wasps that turn aphids into crusty mummies.

Natural enemies of aphids such as lady beetles and lacewings will come into your garden naturally when aphids are abundant. Protect these good bugs by avoiding the use of insecticides that may be toxic to a broad variety of insects.

• Non-chemical pest control methods should be used first to manage aphid populations. However, if you feel insecticides are necessary, choose less toxic products.
• Insecticidal oils and soaps are the safest products. When properly used, these materials solve most pest problems.
• Oils and soaps work by smothering aphids, so application must be thorough. Don't apply to drought-stressed plants or when it is very hot. A few plants are sensitive to these products.
• Insecticidal soaps, soap-pyrethrum mixtures, or neem oils are often applied on vegetables or small bushes like roses.
• Narrow range oils, like parafinic, supreme or superior oils, are appropriate for larger trees.
• Oils and soaps don't kill aphids hidden within curled leaves. Prune these out. Systemic insecticides can kill hidden aphids, but they are much more toxic and not registered for use on garden vegetables or fruit trees.

What you use in your landscape affects our rivers and oceans!