I've seen where the wilt is moving in WI and MN. It is spreading more. I don't do anything now except watch for trench failure and I will put in a secondary trench as soon as mine is repaired.
Bobcat was quick. Not more than 2 hours after they picked it up yesterday, the service manager called to tell me he found a problem and was working with Bobcat to get a new boom and get it set back up. I am thinking, though, of going back down to 4' to offset some of the play that the 5' extension has.
If I had the time, labor, and money, I could install trench barriers. We have a few miles of fenceline, though, and it would be cost and time prohibitive to go through all of that. Other than Cedar Elm trees that grow to 50-60', we don't have any other real big trees here unless you come across some second generation cedars in the 30-40' range. Losing big, mature and full 30' live oaks can really wreck your views.
I've been lucky for the nearly 20 years I've been at this place. It's always been around us and new centers can start from bugs but we try to paint any wounds from clearing, sawing, or grading roads. I can't get to every wound from wind or ice storms but I try. I guess what I'm getting at is prevention seems to be the cheapest way to deal with it and that's why we tried the trench. I don't think I got everything the first try so that second trench will help a lot. Now the waiting begins and the watching.
"You Can All Go to Hell, I'm Going to Texas." --Davy Crockett