Japanese Lilac - Not healthy. Help!

Asked August 12, 2020, 1:39 PM EDT

Landscaper planted this Japanese Lilac (7 feet tall - was a large potted) about 6 weeks ago, just before all the hot weather. Looked full and healthy. It was recommended daily watering for first 1-2 weeks, then every 2nd or 3rd day after that. Give roots a good soaking. Gets 5-6 hours sun per day. Has been steadily loosing leaves and many existing leaves showing brown spotting. See attached. Could this be a fungus? Too much or too little water? Advice appreciated Steve Budnik

Carver County Minnesota

1 Response

It is probably infected by the bacterial blight of lilacs running rampant this year. It rarely kills the lilac and good sanitation will reduce it next year.
https://hortnews.extension.iastate.edu/lilac-bacterial-blight
Another possibility is anthracnose, a fungal disease that is more common in humid wet weather.

For an accurate diagnosis samples can be sent to the plant disease clinic.
https://pdc.umn.edu/