Crown gall is a bacterial plant disease. Rose bushes are especially vulnerable to crown gall. An infected plant develops tumor-like growths along the base of the plant and roots. Infection occurs when bacteria enters the plant by a wound, such as one from grafting or an injury from a careless gardening tool. Left untreated, the plant will become weak and eventually die. When treating the plant, it is vital to regularly sanitize the gardening shears, by dipping blades in rubbing alcohol. Failure to do this can spread the infection to another part of the plant or to another plant.
Remove the soil around the infected area to expose the growth using pneumatic equipment, such as an air compressor to blow the soil from the area.
Cut off the infected parts of the plant. Between each cut, dip the shear blades in alcohol or formaldehyde.
Flame the growth instead of cutting. While this would not be appropriate for a rose bush, it may be necessary when treating some trees. Position the tip of the torch along the margin of the gall and move around it, creating an inch-wide hot zone.
Spray the plant with a bactericide. Consult with your gardening center for the appropriate bactericide for the type of plant you are treating. Treat the affected plant twice a month. Follow the manufacture's application instruction for the plant type.
Remove the plant and its roots entirely in severe cases, or if the potential for the disease to spread is significant. Crown gall is difficult to treat effectively, and it can spread to other plants.