Large Maple Leaf Tree infested with Verticillium Wilt

Asked July 25, 2019, 12:28 PM EDT

I've had two ISA certified arborists from same company look at my large maple leaf tree in backyard with one telling me it is not diseased and needs tree spikes & quick release nitrogen 10-10-10 to recover and the second one from same company telling me our tree has Verticillium wilt and will die within a year. Not sure who to believe yet if tree can be saved, I prefer that method. If it needs to be removed and replaced with another type tree, I am okay with that. I took picture of tree about 3 weeks ago and am including it with my question. Would appreciate your insight on whether our tree can or cannot be saved. Thank you. Paul Webber Beaverton OR

Washington County Oregon forestry trees and shrubs urban forestry

3 Responses

Paul: From the picture, the tree doesn't look healthy. There is a persistent pattern of sparse growth and smaller than normal leaves. This would indicate a vascular/root problem like Verticillium wilt, a soil-borne fungus ( https://pnwhandbooks.org/plantdisease/host-disease/maple-acer-spp-verticillium-wilt) .Often it shows up in one sector of a tree first and then progresses to the entire tree. I have seen smaller Japanese maples succumb fairly quickly and big leaf maples (our native species) lose portions of the tree but survive for years, albeit in a somewhat compromised state. I worry about trees with infected roots and vascular tissue being a hazard. Again, based on this picture and the apparent reduction in vigor over the whole tree, I would recommend removal. There is no cure for Vert wilt. If I have read the picture wrong or there is more to the story, give me a call. Chip 503 397-3462 chip.bubl@oregonstate.edu

Chip

Thank you for your honest assessment of our large leaf maple. Based on your recommendation to take tree down, my followup question is whether I need to somehow treat the soil for the Verticillium Wilt if I elect to plant a replacement tree resistant to this fungus such as dogwood, birch, conifer, or sycamore? I read about putting down 1-2 mil plastic sheets over the soil for 4-6 weeks to kill fungus or do a preplant soil test. I prefer just planting a replacement tree like a dogwood or sycamore......

Paul Webber

Paul: Here is a list of trees resistant or susceptible to Verticilium wilt. I don't think there is a practical way of removing the fungus from the soil in a landscape setting. hope this helps. Good luck. Chip