Crown gall is a bacterial disease caused by Agrobacterium tumefaciens, which causes the formation of galls on roots, twigs, and branches, often close to the ground level.
Inspect all plants carefully before planting - avoid any plants with swollen root knots.
Plant resistant species (e.g. potatoes), at least one year after infection, because the bacteria can persist in the soil.
Improve soil drainage (e.g. by adding compost to the soil or rocks to the bottom of the pot). Ensure having drainage holes at the bottom of the pot.
Use resistant species and cultivars as well as healthy, certified seeds and seedlings.
Avoid mechanical damage to plants. Injuries provide a point of access for the bacterium.
If possible remove and destroy the infected plant. Burn it or toss it into the garbage. Do not compost.
