Aphids are common in your garden because:
■ Aphids like lush new growth. Don’t over fertilize.
■ 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 reduce aphids:
■ Prune out infested leaves and stems.
■ Knock aphids off plants by shaking the plant or spraying a strong stream of water.
■ Protect seedlings with covers.
■ Wait for hot weather; most aphids are heat-intolerant.
Protect aphids’ natural enemies:
■ Lady bugs (larvae and adults), lacewings, syrphid fly larvae, soldier beetles and parasitic mini-wasps.
■ Beneficial insects will come into your garden naturally when aphids are abundant. Protect these good bugs by avoiding the use of insecticides that can be toxic to a broad variety of insects.
If insecticides seem necessary, use the safest products:
■ Use nonchemical pest control methods first.
■ Insecticidal oils and soaps are the safest products. When properly used, these will solve most insect problems.
■ Oils and soaps work by smothering aphids, so apply thoroughly.
■ Soaps and oils are best for vegetables and roses. For larger trees such as crepe myrtle use a narrow range horticultural oil.
■ Systemic insecticides can kill bees and beneficial insects.
Rose plants get a lot of aphids in the spring. My tip is to squish them. I get great satisfaction squeezing the aphids between my fingers.
For more information go to: ipm.ucanr.edu
■ For more gardening advice or topics from the Colusa County Master Gardeners, visit http://cecolusa.ucanr.edu