Skip to content
Pocket Botanist
Get the app

Guides

Fire Blight

Disease

Fire Blight is a bacterial disease that causes sudden wilting and blackening of plant tissues. It is a serious concern because it can rapidly destroy branches or even kill entire trees in the rose family.

Symptoms by part

Leaves

Leaves suddenly wilt, turn dark brown or black, and remain attached to the branch.

Stems

Tips of branches curl into a characteristic shepherd's crook shape and the bark may show sunken, dark cankers.

Flowers

Blossoms appear water soaked and shriveled before turning brown or black.

Fruit

Young fruit turns black and shrivels while still on the tree, often exuding sticky bacterial droplets.

Causes

  • Warm and humid weather during the bloom period.
  • Splashing rain or heavy dew that spreads bacteria.
  • Pollinating insects moving between infected and healthy flowers.
  • High nitrogen fertilization that encourages soft, succulent growth.

Could be confused with

  • Frost damage · Frost damage usually affects all new growth uniformly across the plant rather than specific branches.
  • Bacterial canker · Bacterial canker often causes gumming or sap oozing from the trunk and main branches rather than the shepherd's crook tip dieback.

Treatment

  1. Prune out infected branches during dry weather, cutting at least 8 to 12 inches below the visible damage into healthy wood.
  2. Disinfect your pruning shears with a solution of one part bleach to nine parts water between every single cut to avoid spreading the bacteria.
  3. Remove and destroy all pruned material by burning or bagging it for disposal, never composting it.

Without chemicals

  • Prune during the dormant season to reduce the amount of bacteria present before spring.
  • Avoid overhead irrigation to keep foliage and flowers dry.
  • Select resistant plant varieties when planting new trees or shrubs.
  • Reduce nitrogen fertilizer applications to prevent excessive succulent growth.

Preventing it

  • Sanitize all pruning tools thoroughly after every use.
  • Remove any wild or neglected host plants nearby that could harbor the bacteria.
  • Keep the area around the base of the plant clear of debris.
  • Avoid planting highly susceptible varieties in areas with frequent spring rain.

Season

The warm growing season, especially during spring bloom and periods of high humidity.

Spread risk

High

Severity

High

When to act

Act immediately upon spotting the first signs of wilting or shepherd's crook tips to prevent the bacteria from reaching the main trunk. If the infection reaches the main trunk or root crown, the plant is likely beyond saving and should be removed by a professional tree surgeon.

Think it's Fire 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.

Download on the App StoreGet it on Google Play

Get the app · Or check it from a photo now, free

Questions people ask

Will my plant recover on its own?
No, Fire Blight is a progressive bacterial infection that will continue to spread through the plant until it is physically removed.
Can I compost the infected branches?
No, the bacteria can survive in compost piles and potentially reinfect your garden later.
Why did my tree get this if it was healthy?
Fire Blight is highly opportunistic and often enters through flowers during spring weather, regardless of how well you have cared for the plant.

Plants it affects

Back to all guides

This guide was generated with AI and is general information, not horticultural advice. Read about how we build these guides.