In the Garden with Pat Rubin

Bee garden writer Pat Rubin writes about everything that grows, from flowers and trees to vegetables and lawns. Pat volunteered for several years as a Placer County Master Gardener and has written about gardening for many national and regional publications. In addition to gardening, she spends time raising and showing miniature horses and miniature donkeys.

In the Garden will include news, events, advice and other gardening tidbits. Pat will also answer reader questions.

• Ask a question

« Tomato cages using remesh | In the Garden front page | Bean seed failure--damping off »

April 16, 2007

Controlling whiteflies

Several readers have asked about controlling whiteflies. They're pesky, yet tiny, insects that seem to come in droves. The adults have a white, waxy covering on their bodies. Both the larvae and adults suck plant sap, causing leaves to yellow, dry up and fall off. Further, they excrete honeydew, so the leaves can feel sticky. According to the Sacramento County master gardeners, a multi-pronged attack is the best way to get whiteflies under control.

First, since they like dusty, dry places, hose plants off every morning. Be sure to spray the undersides of the leaves since that’s where whiteflies like to hang out. Insecticidal soap also works, but remember that you have to actually spray the insects.

Also, try something reflective, like aluminum foil, beneath the plant. Ideally, the whiteflies see the reflection of the plant and the sky in the aluminum foil and fly away from it.

Plants like dill, goldenrod, cosmos, alyssum, marigolds and angelica attract beneficial insects (lacewings, ladybugs) that feast on whiteflies.

Finally, be persistent. Don’t give up because it may take a while to knock down the whitefly population.

The master gardeners have an information sheet about whiteflies. You can order it by sending a stamped, self-addressed envelope to PN #7401, UC Cooperative Extension, 4145 Branch Center Road, Sacramento, CA 95827. It’s also available online.

Ask a question

Please use the form below to submit your question. Because there is a 100-word limit for questions, a word counter is located directly beneath the box where you enter the your question.