Dutch elm disease is a major killer of elms in our area. We highly recommend prevention treatment for this disease. Prevention injections typically last three years and are over 90% effective. Once a tree contracts dutch elm disease the treatment protocol is very invasive and only 10-20% effective.
Are your maples losing their leaves in the middle of the canopy? That is typically a sucking insect called gloomy scale. Gloomy Scale is easily treatable but if left untreated will often kill the tree.