It’s hard to think of insects in winter, but don’t forget the havoc these tiny creatures can bring to your garden – defoliating leaves, contaminating produce, even destroying complete plants. Before these pests begin to be a problem is the perfect time to take steps to control them.
Why Winter Control?
Late winter is the right time to control insects for two reasons. First, the insects and their eggs are just coming out of dormancy. The shells and protective coverings are softer and more porous in late winter, and so are more vulnerable to the effects of oils and sprays. Second, the oil-water mixture should not freeze on the tree or plants, which could damage the plant and make the spray far less effective. When you spray, the temperature should be above 40 degrees. Delay spraying if freezing night temperatures are predicted. Choose a calm day for spraying to be sure stray breezes and cross winds do not spread the spray to plants you don’t want covered.
Insects to Control
In late winter, before any leaf buds begin to open, spray Bonide All-Season Oil or Dormant Oil Spray on fruit trees or other ornamental trees or shrubs to suffocate over-wintering aphids, thrips, mealybugs, whitefly, pear psylla, scale and spider mites that cling to the bark. The treatment will also destroy the eggs of codling moths, Oriental fruit moths and assorted leaf rollers and cankerworms. Don’t wait until the buds have burst in early spring, as the coating of oil will also smother the emerging plant tissue.
Tree Spraying Tips
While small shrubs can be easy to treat, larger trees are more challenging to be sure you don’t leave any area untreated where insects can thrive. Spray the whole tree at one time, concentrating on the trunk, large branches and crotches, rather than spraying down a whole row of trees at one pass. If you’ve experienced extremely bad infestations of insects, you might treat your trees a second time. But be sure to spray before the buds are near the bursting point. Dormant oil can also be used after the leaves have dropped in the fall. Never spray when any foliage or fruit is on the trees or you risk unwanted pesticide contamination.
After you spray, be sure to store any remaining oil properly and out of reach of children and pets. Containers should be labeled clearly and kept in cool, dark spaces to preserve their usefulness. Avoid reusing any sprayers to minimize the risk of cross contamination or inadvertent use.
Spraying for insects in winter may not be the most glamorous job, but you’ll appreciate the improvement in your trees through the spring and summer when you’ve nipped your insect problems in the bud.