Foam on blackberry roots
Hello! I am growing prime ark blackberries. They have developed a foam at the crown of the plant. Some of places where there is foam have weakened the canes and then canes are falling off the plant. The leaves and canes are healthy, stocky and green. Only some of the plants have the sticky white foam at the crown, just where the canes come through the dirt from the roots. Please help me save my blackberries! Thank you!
Livingston County Michigan
Most likely this is spittlebug, a common garden pest.
If you dig under the foam you will likely find small aphids about 4 to 5 mm long.
The following link from the University of Minnesota gives pictures and control remedies:
Basically you use a hose or your hand to remove the foam and the underlying spittlebugs. Periodically check back to see if they have returned and, if so, physically remove them again.