Treatment of soil to control aphids

Asked October 4, 2020, 11:46 PM EDT

Our Cole crops have been overrun by aphids this year -- clouds of them on each kale and Brussels sprout leaf. Our regular treatments with insecticidal soap, Spinosad, and Neem oil may have slowed them a bit, but have not been effective for control. We have pulled the infected plants but are concerned about eggs and overwintering adults in the soil coming back next spring. Is there a recommended treatment of the soil to kill them? Thanks Dan Fleishman Corvallis

Benton County Oregon

1 Response

Aphids don't overwinter in the soil.

The key to protecting your kale and Brussels sprout leaves against aphids (also caterpillars) is to begin the gro ing season with floating row cover secured/over your newly planted seeds or transplants.

The row cover should be loosely bloused (and height) over the plants, allowing plenty of growing room. Then, too, the edges must be secured so that the pests can't sneak inside the protection.


Then, if it happens that you do find aphids on the plants, act as soon as possible. A harsh water spray can be an effective treatment if repeated every several days.

The main problem with spraying aphids with either water or pesticides is that you are guaranteed to miss some. Those few aphids will continue giving live birth to already pregnant youngsters! That's the reason to be persistent with repeating the spray, whatever it is.