I have about a dozen ash trees on my property that I would like to try to protect against the coming EAB invasion. I am going to treat the smaller ones with Imadacloprid applied to the drip line roots, but the larger trees will be treated with Emamectin Benzoate using the Arborjet system. However, now that the hot, dry dog days of summer are setting in, I am worried about uptake and wonder if I would be throwing money away. Would it be better to take my chances and wait until next spring to treat them? I am not currently seeing any signs of active infestation, but I know that EAB has been found in my area. I have had a couple of local arborists evaluate the trees and give me estimates, but I don't want to spend the money needlessly. I would have to hope that they would be honest with me if it is too late to treat the trees, but you never know.
If I proceed with the treatment this year, I assume I should wait for a decent rain event, right? Has anyone had any luck treating with trunk injection in the hot, dry months?
Thanks in advance for your opinions.