What is going on with my trees?
I have 2 ornamental plum trees that the tops branches are not leafing. These 2 trees have been here since about 1986 the neighbor in the court helped plant them. I thought the trees were just getting old though they are still flowering and giving fruit for the birds. But now I noticed that a young tree that I planted about 6 or 7 years ago, a type of maple, which gives pink flowers in the spring time and no fruit is having the same issue. Most branches are leafing but some of the very top twig/branches are not leafing. Any ideas what is going on? Now I noticed the neighbor has a tree about 15 years old doing that same thing, so 4 trees with similar issues, they are all in the same area but they all have plenty of sun and we have a sprinkler system,is it lack of water?