Black Spot On Roses

Black spot on roses is among the most common rose diseases you will find in your garden.

This disease is caused by the fungus Diplocarpon rosae. Like the name suggests, the first symptoms of this are black spots on the leaves. Without treatment, the spots will add a yellow ring around them, eventually infecting the whole leaf. The leaves will then completely die and drop off. Yes, its pretty nasty.

LIke all fungi, this disease will spread rapidly in damp, moist conditions. Excessive water on the leaves can create a breeding ground. You should concentrate on watering at soil level, this is more efficient in any case. A bright, sunny area will help evaporate any excess water and keep conditions dry. Remove infected leaves immediately, as it can quickly spread to other spots. Destroy the leaves and don't mix in with compost.

Also, keep an eye out on new leaf growth. New leaves are especially susceptible to this issue.

You can use fungicides to help control this disease to some extent. If you've been hit with a lot of black spot on roses, sometimes the best idea is to plant more disease-resistant varieties that can hold up better.