Fruit tree canker
Sunken, cracked patches in the bark of apple and pear, with ring-shaped ridges around an open wound; in winter, tiny red balls appear on them. Twigs and branches above the canker die back.
The fungus Neonectria ditissima enters through pruning cuts, leaf scars and frost damage, especially on wet, heavy soil.
What can you do?
- In dry weather, cut or saw out affected twigs and branches well into healthy wood.
- On thick branches, pare cankers back to healthy green tissue and disinfect your knife and saw after each cut.
- Take the diseased wood away (general waste or recycling centre) and don’t leave it in the garden.
- If the canker is on the trunk or main limbs of a large tree, have a tree surgeon look at it.
Prevention
Prune in dry weather and not during leaf fall in autumn, choose less susceptible varieties and avoid wet, poorly drained soil.
When to watch out: October–March