Aphids on Linden Trees
Hello, we have linden trees on our street and they attract aphids like crazy - the aphids then drop their “dew” on everything under them and can sometimes ruin other plants in our garden. Is there something I can do now or next year to help prevent so many aphids? I release ladybugs annually. I am wondering if there is some other natural treatment for the tree to deter the aphids in the first place? Thanks for your help!
Washington County Oregon
Control of aphids on large linden trees trees with contact insecticides like insecticidal soap and horticultural oil would be very difficult since you need through coverage of the material and would need to reapply it regularly to be effective.
Unfortunately, only acepahate and imidacloprid can be applied as a soil drench. Both of these systemic insecticides are considered "harsh" chemicals. Since there are now restrictions on using neonicitinoids on lindens, then acephate would work for your situation.
If you are interested in determining the relative hazard of insecticides, see Grow Smart, Grow Safe: http://www.growsmartgrowsafe.org/