Pocket BotanistSymptoms by part
Stems
Look for dark, reddish brown or purple lesions that often start around wounds or insect feeding sites. As the infection progresses, the bark may crack or peel, and the wood underneath turns dark and brittle, eventually causing the cane to wilt and die above the infection point.
Causes
- Wounds caused by mechanical damage during pruning or cultivation.
- Feeding damage from insects like the raspberry cane borer.
- High humidity and frequent rainfall that splash fungal spores onto open wounds.
- Poor air circulation within the planting row.
Could be confused with
- Spur Blight · Spur blight typically appears as purple or brown spots specifically around the leaf buds, whereas cane blight lesions are usually centered around wounds and cause more severe cracking.
- Anthracnose · Anthracnose presents as small, sunken, circular spots with light centers and purple margins, which look quite different from the larger, irregular, and woody lesions of cane blight.
Treatment
- Prune out and destroy any infected canes as soon as they are spotted to stop the spread.
- Cut the infected canes back to the ground level, ensuring you remove all discolored wood.
- Sanitize your pruning shears with a solution of one part bleach to nine parts water between every single cut to avoid spreading the fungus to healthy canes.
Without chemicals
- Remove and burn or dispose of all pruned plant debris away from the garden.
- Thin out the canes to improve airflow and reduce humidity around the base of the plants.
- Avoid wounding the canes during routine maintenance or harvesting.
Preventing it
- Control insect populations that cause physical damage to the canes.
- Space plants properly to ensure good air movement.
- Water the soil directly at the base of the plants rather than overhead to keep the canes dry.
- Keep the area around the base of the plants free of weeds to reduce moisture buildup.
Season
The warm growing season, especially during periods of wet or humid weather.
Spread risk
Moderate
Severity
High
When to act
Act immediately upon seeing any signs of wilting or dark lesions on the canes. If the entire plant is severely affected and failing to produce, remove and replace it entirely.
Think it's Raspberry Cane Blight?
This guide covers the general picture. Pocket Botanist looks at your actual plant from a photo and tells you what's really going on, how serious it is, and what to try first. Identification and a health check are free.
Questions people ask
- Can I compost the infected canes?
- No, you should not compost infected material because the fungus can survive in the pile and spread back to your garden. It is best to burn or bag and dispose of the material in the trash.
- Will my plant recover if I just leave the infected canes?
- Unfortunately, the infection will likely continue to spread down the cane and eventually kill it. Removing the infected parts is the only way to save the healthy portions of the plant.
Plants it affects
This guide was generated with AI and is general information, not horticultural advice. Read about how we build these guides.