Use small-flowering plants to attract beneficial insects to your garden, a photo by Gerris2 on Flickr.
I planted Coriander, mustard, and 2 kinds of dill purely for the small flowers they produce. The flowers are nectar sources for beneficial insects that feed on aphids, mites and other pests. It's working, I see many many Syrphid flies on the flowers. No aphids in sight! Mites are at an all time low!