Q.Large, Older Willow Tree In Northern Wisconsin Has Large Cavities At Base Of Trunk And Appears To Have Insect Damage.
Can we treat the willow tree infestation in the fall? What is the best product to use? What about the cavities? Please tell us how to treat and and save the tree?
Certified GKH Gardening Expert
Damage to a tree's internal tissue is not usually a big concern. However, in this situation there could be a few issues. My first concern is that the structure of the tree is compromised. If the base is completely hollow then the tree is at risk of falling.
You may try treating this by pouring concrete into the cavity. Sometimes this helps, and sometimes it doesn't.
Treating the insect infestation is going to be necessary as well. There are many ways to do this, but to risk harm to the tree I would choose a more natural method. Neem oil or its extract, azadirachtin, Works wonders.
You will want to contact your local extension service as they can help you, locally.
https://www.gardeningknowhow.com/extension-search
https://www.gardeningknowhow.com/ornamental/trees/tgen/patching-tree-hole.htm
https://www.gardeningknowhow.com/plant-problems/pests/pesticides/azadirachtin-vs-neem-oil.htm
