I have planted 5 small lilac bushes over a hear ago. They are all now about 3...

Asked November 18, 2015, 1:31 PM EST

I have planted 5 small lilac bushes over a hear ago. They are all now about 3 feet tall.This fall I noticed they all have black dots on the leaves. They are not bugs (at least they don't move if I stare at them awhile) and they don't rub off. I do not want to lose these bushes after caring for them for 1 1/2 years. What might this be and is it harmful to the plants. Is there something I can do yet this fall about it or over the winter. If not, what can I do to protect/save these young bushes in the early spring?

Hennepin County Minnesota

2 Responses

We have had a lot of rain this year and black leaf spot and other fungus maladies of trees and shrubs tend to thrive in persistently moist conditions. From what you describe, we dont believe the spots on your lilac's leaves are too harmful and certainly not life threatening. Overall leaf spot diseases do not seriously harm trees and shrubs unless they persist for several years.

The best thing you can do right now for your lilacs is to rake up and destroy fallen leaves before the first snowfall to eliminate locations where pathogens can survive to re-infect the plant the following growing season.

Here is a good link from our University Extension service with more information - be sure to look at the preventive care and maintenance practices at the end of the article:

Thank you for your response. I am very happy that this seems to be resolvable and non life threatening to my young lilac bushes. I will watch them carefully next spring and ask again if I see that the spots continue to invade the leaves. Jackie