Japanese Lilac tree

Asked August 22, 2020, 2:03 PM EDT

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

1 Response

Based upon your description we assume the tree is beyond recovery, and as to what caused its decline and death we can't say without more information.

According to arboriculture experts at the University of Minnesota, tree lilacs are moderately long-lived and can be expected to live 40-50 years.

Laboratory analysis is sometimes needed to determine the cause of plant death but if the tree is entirely dead it may be too late of collect or submit samples.

Borers, crown gall and verticillium are three things that might account for the tree's relatively sudden decline and death.

If you plan to plant another tree lilac, it's important to rule out verticillium because this disease persists in the soil and another lilac planted in the same location might also become infected.