The spring or fall is probably the best time, like you said, but we talked with the company, Arbico several times before they sent the nematodes. The instructions were to apply the nematodes in early morning or evening, avoiding the heat of the day and then keep the area watered. It was actually the First week of June when we did the first of two applications.
We are in a heavily wooded area so it's no surprise that there are termites around. And the trees shade the south side of the house where we found the termites. We discovered a construction flaw that was allowing water to drip down into the area behind the HardiPlank so the framework was starting to rot! Luckily we noticed the little trails of termites going up the slab from the ground. And luckly my hubby is quite handy and was able to make the repairs himself, replacing the damaged wood and fixing that area where the water was entering!
It took about at least month before we stopped seeing the little trails reappear, after knocking them off!! I haven't seen any trails for over a week now.
