Clubroot is a serious problem in gardens, with broccoli, cabbage and cauliflower vulnerable to its attack.
- Clubroot is caused by a soil-borne fungus -- Plasmodiophora brassicae.
- The fungus infects plants, getting in through the root hairs. The roots them become swollen and deformed -- hence the name clubroot. This leads to cracking and rotting.
- As a result, the plants can't absorb water or get their nutrients. And that leads to plant failure.
- It's tough to spot from the surface, since your plants might be a little wilted or have slight browning on the edges of leaves. But under the ground, there's much afoot.
- Wind, water and garden tools can spread the fungus, and warm weather encourages it to flourish.
- Keeping the soil at a slightly acidic pH of 7.1 - 7.2 could help hold the fungus at bay.
- Fungicides are of little to no help. Remove the plants and the soil and dispose of them -- no composting or burning.
- Only use plants that are resistant to the fungus.