Fire blight
Blossoms and shoots of pears and apples suddenly blacken, as if scorched.
What you'll see
- Blossoms and young shoots suddenly wilt and turn black or brown.
- Shoot tips bend into a shepherd's crook, and dead leaves cling on.
- Sunken cankers that ooze slime in wet weather.
Why it happens
A bacterium survives the winter in cankers. Rain, insects and bees carry it to blossoms and soft shoots in warm, wet springs.
How to fix it
- Cut out infected shoots 12 to 24 inches (30 to 60 cm) below the visible damage, ideally in dry weather.
- Clean pruners with 70% rubbing alcohol between cuts.
- Bin the prunings, and pick off late blossoms before they open.
Keep it from coming back
- Plant resistant varieties of pear, apple and pyracantha.
- Avoid heavy feeding and hard pruning, which push out soft, easily infected growth.
- Don't water trees overhead while they are in bloom.
Sources
General guidance, not a diagnosis. For valuable, edible or outdoor crops, check with a local extension service or plant expert. Use any product exactly as its label says, and keep children and pets away while it dries.