Spider Mites Can Be Controlled

Spider Mite Damage But Obviously Not Tomato.
What to look for? Yellow speckling or stipuling,
dusty appearance on the leaves, webbing may or may
not be present.

Q. I am hoping that you can help me, to help my son. He lives in southern California, with a young family. In order to make ends meet, he has created a good size garden for his family, to have fresh vegetables. Some of his tomatoes are getting ready to be harvest, but his crops are being plagued by spider mites. He has released a large amount of lady bugs, from his local nursery, but they don't seem to be solving the problem. Is there something that he can treat his crops with, that will not contaminate the vegetables? Please give me some "fatherly advice" for him.

A. When your son purchases transplants in the future try to find a supplier who is growing them by using only organic pesticides. Some growers will spray transplants with a hard pesticide to knock everything down before shipping them out. This way they get to market looking pristine and with few insect problems.

The problem with this approach is that spider mites are controlled by other insects and predatory spider mites. Once these predators are killed any new infestation of spider mites takes off like a rocket since they reproduce so quickly and their predators are gone.

Spider mite population explosions are enhanced if plants are covered in dust. Wash them periodically, particularly after a wind may have covered the leaves in dust. As far as chemical controls of an organic nature try the use of insecticidal soaps or horticultural oils or perhaps both.

I have heard some recommendations that include the use of Neem oil but people are recommending mixing a soap or detergent with the Neem oil. No, no, no. You must never mix a surfactant or any kind of soap or detergent with oils. This destroys the basic property of an oil that kills insects; namely suffocation. Use both of them, but use them separately or alternate their use.

Insecticidal soaps must be applied every 3 to 4 days or no more often than the label recommends but spray to include the undersides of the leaves for any chemical control to be effective. Never spray in the hot times of the day but only very early in the morning or late at dusk when bees have returned to their homes. Bees will succomb to these sprays. I hope this helps your fatherly advice.