Good Morning------I have a walnut tree in the back yard. Five to ten years old, about 6 inch trunk, as high or higher than my bi-level house. Been very healthy looking, some years has walnuts. Last year (2020) it was attacked with aphids. Lots of them ! I purchased a concentrate that kills aphids. Mixed with water in a battery operated sprayer, to reach the top of the tree. Worked fine. Applied two sprayings. about a week apart. Got rid of the aphids. This spring (2021) the tree produced no buds and no leaves. What might have happened ? Later in the spring, suckers started growing from the bottom of the trunk. Lots of them. Some of them are over six feet high (August 2021) and look very healthy. Should I cut the dead tree and save one or some of the suckers to produce a new tree ? How should I be dealing with the suckers ? Maybe the tree is not really dead ? I have broken off some smaller branches, and they were very dry. ANY HELP ?? Donald King-----Golden, Colorado