When are the best 2 times per year to spray hemlocks with oil dormant spray for adelgids? |
Horticultural oils are sprayed year round to control hemlock wooly adelgid, although the dilution rate is different for summer so you should read and follow the label instructions very carefully. If you can achieve complete coverage, the first application should do it -- maybe you will not need to spray your trees again. For the most up to date control suggestions for your area, you may wish to contact your county extension at 599-6162. |