Q: My tomatoes are covered with aphids. What in the world can I do to control them?
A: Aphids damage tomatoes in two ways: they suck sap from the stem and leaves and they excrete honeydew, which covers nearby plant surfaces and attracts sooty black mold, which disfigures the fruit.
Fortunately, aphids are easy to control. Many can simply be washed from the plant with a blast from your garden hose. Insecticidal soap kills them easily if you are careful to spray the undersides of leaves, where they hide.
Garden insecticides are very effective as well…just remember to follow the label instructions for when you can pick the fruit after spraying.