I have a Manitoba maple of about 60 feet high growing in my back garden close to the fence shared by my neighbour. Last winter it lost a few limbs but withstood the storm. I know that it is a weak wood tree and am worried that as it gets older it may fall. Would it be a good idea to trim the top third of the tree to make it shorter or would the new growth make it top heavy and worse? Should I just get the tree “cleaned up” so the wind can pass more easily through the centre? Many thanks.
The Manitoba maple, (Acer negundo), also known as Box elder, does indeed have weak branches that tend to break during storms. It is a short lived tree that grows to 60 feet. It also has shallow fibrous roots, all concerns during storms. It does not handle pruning well. It sends out a multitude of shoots at any pruning site, which will be an issue if you remove the top 1/3 of the tree.
Consultation with a reputable arborist would be the wisest path, especially since your tree is so close to a fence and presumably to other houses.