Last summer my ash tree (Fraxinus) lost all its leaves prematurely (middle of summer/end of summer). I picked them all up one by one in order to not have the disease overwinter. The trunk of the tree had small black spots on it, and still does this time of year. Normally this tree should have opened its leaves by now. But it hasn’t yet. When scratching small pieces of bark, underneath it is green, so there is life left in it. However this tree seems totally dormant. Is there any way to get a tree out of dormancy?
Thank you for your help,
Unfortunately, your ash (Fraxinus) has probably succumbed to the emerald ash borer (EAB) rather than having gone dormant. This metallic green wood-boring beetle is about 1 to 1.5 cm long. It attacks all native species of ash trees usually killing them within 2-3 years. In recent years the problem has received plenty of media attention. EAB reached the Toronto area in 2007. This infestation has decimated the numbers of ash trees in Toronto.
Typically the beetle burrows into the bark of the tree leaving d-shaped holes. It lays eggs in May from which the larvae emerge and tunnel beneath the bark and feeding on nutrients within the tree. Eventually this destroys the tree’s entire vascular system and you see signs that the tree is in trouble. Foliage wilts, turns yellow and drops. You can do a Google search : “ash tree with borer damage” for images of the problem. For further help in identifying whether or not your tree is infected the following documents will be extremely useful:
https://www.nrcan.gc.ca/forests/insects-diseases/13395 (Natural Resources Canada)
https://www.yourleaf.org/emerald-ash-borer (Leaf -an organization dedicated to the protection and enhancement of the Urban Forest)
If it is determined that the tree is infected it will need to be removed and for that you will need to hire a tree care professional.