Hey Al, I treated them pretty early on. They were recovering but had started to grow some roots and leaves. The earlier you treat the trees, the better. The RKN goes through different life stages and grows and reproduce faster when the temperature is warmer or if your trees are on a heat pad.
For the beneficial nematodes that attack the RKN, I used several treatments just to be safe.
I used the Monterey Nematode Control first to quickly wipe out any living nematodes and then I waited several weeks to a month later before using the beneficial nematodes because I didn’t want to kill the beneficial nematodes with the residual Monterey Nematode Control.
The beneficial nematodes will be longer lasting and multiple applications will ensure that eggs laid at different times will be taken care of.
Simon