Crown Gall

Crown gall is a nasty bacteria caused disease for your plants.

This ugly disease is caused by a bacteria called Agrobacterium tumefaciens. Unfortunately, it is common in most soils and can affect more than just roses. Fruit trees and other rooted plants are also very susceptible to it. Its not obvious to spot either. You need to look down at the root line where stem and roots meet.

Crown gall, much like stem canker, can be caused by open lesions and cuts exposed to infected soil.

The most recommended solution for this issue is simply to dig up and eliminate the infected plants. Unfortuneatly, there is no good cure for an infected plant.

If you have a patch of soil that seems to breed this disease frequently, you can try planting a grass or other plant that is not affected by it. After a few seasons, the bacteria will die off and you can try replanting. You can also try a fumigant, although this is only really recommended for controlled nursery soil.

Grafting operations are also where this disease can be spread, so be sure not to mix tools used on infected roses with uninfected. Use a bleach disinfectant to clean between uses.