Lilac Bacterial Blight: Prune and Spray Copper

Lilac: last year's shoots turn black, no bud development. Two years ago only bottom bloomed; last year one bud; this year none. No leaf symptoms.

Diagnosis: Bacterial Blight

Buds/flowers infected before opening, turn black. Similar to winter injury.

Management

• Prune and burn infected parts ASAP.
• Spray copper fungicide now—protects uninfected tissue.
• Prune until mid-July; later risks next year's flowers.

Blight confirmed.