The Botanical Diary
B
FungalSummer–Autumn

Black Spot

Black Spot — a fungal disease affecting garden plants.

Danger level
Moderate
Black Spot

Symptoms of Black Spot

Circular black spots with fringed margins on rose leaves. Yellow halos around spots. Premature leaf drop, weakening of plants. Most severe in warm, wet summers.

How to treat Black Spot

Apply fungicides (trifloxystrobin, myclobutanil) every 7-14 days from early spring. Remove and destroy fallen leaves. Mulch around plants to prevent soil splash. Choose resistant rose varieties.