Winter High Tunnel Pests

As temperatures fade with daylight, high tunnels may becomes a central focus of the farm. The warmth of a tunnel captures heat, keeping soils warmer and providing a comfortable place for farmers and crops, as well as resident pests. 

Common high tunnel pests include aphids, whiteflies, thrips and mites, all of which can build populations quickly. Early detection can help a grower keep a one of these pests from becoming a major problem.

Scout high tunnel crops at least twice a week and look for any plants that appear abnormal or unhealthy. In winter this may mean removing row cover to get a look at crops; this is a good opportunity to monitor soil moisture and crop development as well. Check under plants and leaves for signs of pests. Feeding damage often first appears as slight or spotty discoloration of leaves. Heavy feeding can weaken slower-growing winter plants.

Crop rotation should be applied in the high tunnel just as in the field. Rotating crops and/or tunnels helps break pest life-cycles by depriving pests of their preferred habitat. As you plan your rotations, keep in mind that some pests will happily feed on different crop families, for example, aphids will feed on lettuce, spinach and brassicas.  

If pest numbers rise to concerning levels there are several good options for treatment. Please see the chart below for more info on troublesome high tunnel pests and some of our preferred organic treatment options.