Here’s a description of the garden issue I found:
I have three lilac trees at least 6 years olds. I moved into the house three years ago. The trees are in the South part of the garden getting full sun. They are at least one foot apart. They line the driveway to the garage. They get water regularly especially on hot days. They get fertilizer at least 1-2 times before blooming. They get compost dressing once a year and mulch in the late fall. Last year and more this year, all three trees have few and puny blossoms which turn brown in a couple of days. About 60% of the leaves are brownish, curling or have spots. The branches are semi-bare except for leaves near the end. The tips of the many branches are black, almost burnt looking.
I’m including photos that show the issue.
And here’s what I think is going on
My Lilacs have Lilac Bacterial blight
I conclude that it is blight based on the symptoms I described and on the pictures I posted compared to the resource:
- -leaves look perfectly healthy and then a short time later they look as though someone has placed an open flame near them
- -flowers will wilt and turn brown and unopened flower buds become blackened-disease starts as brown spots on stems and leaves of young shoots as they develop in early spring. A yellow halo may also be around the spot
- -disease starts as brown spots on stems and leaves of young shoots as they develop in early spring. A yellow halo may also be around the spot.
Remedies
1. to take out and plant resistant cultivars or
2. to try to address first by cutting off all affected parts and spray with copper sulfate and not fertilize in late spring (which I did)
Update
I tried to cut off the affected parts over the last 2 days but realized most of the trees were infected, even the suckers. I contacted a tree service who will remove trees and roots and I will buy resistant cultivars.