Japanese Lilac tree
We live in Hennepin County, in Champlin. We have a sprinkler system and this tree receives adequate water as far as we know. We have had our Japanese Lilac tree for just over 20 years. It is south-facing and up to the summer of 2019 had otherwise been very healthy and beautiful. In the spring of 2019 we noticed that only 1/2 the canopy of the tree bloomed and flourished. The other 1/2 appeared completely dead (no leaves, flowers, etc.); completely dead bark. We noticed no bugs or any other abnormality. The trunk appeared, and continues to appear, completely normal. This summer the entire canopy is completely dead. No leaves at all. Is there a life-expectancy of this tree? We shaped it every year and it appeared to flourish every year up to 2019. Any advice you can offer would be greatly appreciated. Thank you!
Hennepin County Minnesota