I love threads like this one. People around me seem to LOVE distributing Carbaryl (Sevin) everywhere -- even on fruiting plants!!! eek!
Okay, here's a tried and true remedy for white flies:
White flies are attracted to the color spectrum of what we perceive as yellow; They tend toward munching the pistils and stamen of yellow-flowering
plants (melons, tomatoes, squash, cirtrus especially, etc.) and that prevents the plant from setting fruit.
Take a 1-foot X 1-foot or so piece of masonite, hardee board or plywood; shouldn't be thick, say 1/4" or thereabouts and paint it bright yellow.
Cover it in clear grease (vaseline, grease) or shoot it with spray glue. If you use spray glue, put it on in one coat so as to not cover the yellow
Suspend this above your yellow-flowering plants. ETA: Suspend it so it can swing in the wind. They whiteflies perceive this as the mother of all
flowers, and land on it. The first time I did this, the board was more white than yellow in a single day.
Scrape the dead whiteflies off and regrease. Rinse. Repeat. Yes, it attracts whiteflies that may have passed your crops by, but it also lures
them away from your crops. It's a pretty natural way to deal with these flower-destroying little buggers.
CUTWORMS around Tomatoes: Cutworms tend toward ringing the base of a tomato plant. I take a 2" piece of old garden hose, slice it down the
middle and wrap it around the tomato plant, pushing it into the soil. Keeps the cutworms at bay until you can spy them and maliciously squish their
little invertebrate bodies between thumb and forefinger.
Yah. I'm violent like that with garden pests.
Companion planting WORKS. I use a lot of marigold around everything. Where I grew up in northern Idaho, the Native American (Shoshone) gardeners
would plant corn first, then beans later, to climb up the corn, and ring the area with squash. Those three do well together, and........ I think
they protect each other somehow, as that combination seems to really do well.
[edit on 23/7/10 by argentus]