Leaf Spot Disease of Lilac

Disease Information

Leaf Spot Disease 

Symptoms and damage

The size and color of the spots largely depends on the type of bacteria at work; in general, the spots are brown or black in color. Some are surrounded by dark margins and others are marked by concentric rings. As the spots spread, they form large blotches centered around the veins of the leaves. If the disease is allowed to progress, the leaves will eventually yellow and drop.


1-Rake up and destroy plant debris of lilac plants affected by leaf spot. Do not compost diseased leaves.

2-Spray leaf spot-infected lilac bushes with a Bordeaux-mixture fungicide. Spray the plants on an overcast but dry day, following package directions for proper application.

3-Make two more fungicide applications, spaced 10 days apart.

Examples of  Fungicides (chlorothalonil - thiophanate-methy )


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