What’s the difference between Crown Gall and Leafy Gall?
Dahlias can suffer from Gall Technically there are two types
Crown gall Caused by bacterium Rhizobium radiobacter (synonym Agrobacterium tumefaciens) which causes the plant to grow in a disorganised way, producing swollen galls.
Leafy gall Caused by bacterium Rhodococcus fascians, which again causes the plant o grow in a disorganised way, this time producing dense clusters of distorted, leafy shoots.
The latter seems to be the most common here in the UK.
Both bacterium enter the plant through wounds in roots or stems. In this video I explain in more detail including examples.
In this video I explain and share examples.