Liliac Bush - Knowledgebase Question

Fruits and Vegetables
Cincinnati, OH
Question by kzloba
April 29, 2007
Hi,

My concern is a lilac bush we have growing in front of the house. It did not bloom this year and many of the leaves are black or with black edges to them. I noticed yesterday that the branches have small holes also. Any idea what is going on?

Thanks!!!!


Image
Answer from NGA
April 29, 2007

0

 What you describe sounds like bacterial blight. Bacterial blight of lilac, also known as blossom blight or shoot blight, is caused by the bacterium Pseudomonas syringae pv. syringae. Chinese, Japanese, Persian, and common lilac are all affected, with white flowering varieties being the most susceptible. Bacterial blight can easily be mistaken for freezing injury from late spring frosts. The bacterium survives winter in cankers, plant debris, weeds, and soil. The bacterium may also be present on healthy plant tissue year round without causing disease. Bacterial blight can be spread by insects, pruning tools, rain, and wind. Infection starts on the newest growth in the spring, during rainy weather. Early symptoms may include dark brown spots with yellow halos, dark brown blotches starting at the leaf margins and advancing inward, blackened shoots, and black streaking on twigs. Leaf spots may coalesce, resulting in shriveling and death of leaves. Shoots may be girdled, causing death of leaves and blossoms. Stress or injury resulting from poor or improper nutrition, frost damage, or wounding can predispose plants to bacterial infection. Control of this disease can be achieved through the following practices: Prune out and destroy infected shoots 10 to 12 inches below visible infection. Sterilize pruning equipment between cuts with 10% bleach or 70% rubbing alcohol to prevent spreading the bacteria. Properly prune stems to increase air circulation and space plants adequately when planting. Avoid overhead irrigation to minimize splashing the bacteria to healthy leaves and other plants. Properly fertilize, water, and mulch plants. Unlike most other fungicides, copper-based fungicides, such as Bordeaux mixture, can be effective against bacterial problems. If the disease is severe, a copper-based fungicide may be applied in the spring to prevent disease from recurring.

You must be signed in before you can post questions or answers. Click here to join!

« Return to the Garden Knowledgebase Homepage

Member Login:

[ Join now ]

Garden.org Homepage
Help using the site
About
Contact
Terms of Service
Privacy
Memberlist
Acorns
Links
Ask a Question
Getting Started Gardening
Newsletter
NGA Merch

© 1972 - 2021 National Gardening Association

Times are presented in US Central Standard Time

Pinterest
Facebook
Youtube
Twitter
Instagram

Today's site banner is by lauriemorningglory and is called "Sunset in the Niobrara Valley"

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.