Fireblight
Blossoms and shoot tips blacken as if torched, and the dying tip curls into a shepherd's crook — the signature. Apples and pears only (plus their cousins quince and hawthorn); it spreads fastest through warm, wet bloom weather.
Disease checklist
Four things to look for. If most of them match what you are holding, you are in the right place.
What gets rid of it
Gentlest option first. For most backyard cases the first one is enough, so try these in order and stop as soon as it works. If you do spray something, the product label tells you how — please read the notice further down.
1Cut it out, 8 to 12 inches below
Prune strikes well below the visible blackening, in dry weather, wiping tools with alcohol between every cut.
isopropyl alcohol 70 percentTry this first2Stop feeding it nitrogen
Lush soft growth is exactly what the bacteria colonize; heavy fertilizer makes trees more flammable, not less.
3Plant resistant varieties
The long-term answer in fireblight country: Liberty over Gala, Moonglow over Bartlett.
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Which plants get fireblight
Every plant we cover that gets fireblight, grouped by type — tap any one to open its page. A note beside a plant came from that plant’s own entry, because the same disease can be a minor nuisance on one plant and a serious problem on another. Plenty of plants we do not cover get it too.
trees5
Plant families hit hardest
Related plants often share the same problems, so if one plant in a family has it, check the others. The largest group here is Rosaceae, with 6 of the 6 affected plants.
- Rosaceae6 plants
When to treat
Infection happens during warm, wet weather at bloom. Cut strikes out in dry weather, well below the damage.
On specific plants
- Dormant
- Dormant Oil (Mites/Scale): Apply in late winter before bud break when temps >40°F for 24 hours. Copper (Fireblight): Apply at silver tip green tip stage.
- Growing
- Watch fireblight in bloom-time warmth.
- Dormant
- Dormant Oil (Psylla/Scale): Apply in late winter before bud break. Copper: Reduce Fireblight inoculum.
- Growing
- Bloom: Streptomycin ONLY if conditions are warm (>65°F) and wet (Fireblight risk). Petal Fall: Insecticide.
- Dormant
- Copper at bud swell where fireblight or rust has history.
Timing only — the label is the law
This page tells you when to watch for fireblight and when treating is worth considering. It is not a recommendation to apply any particular product. Read and follow the product label before you spray — under federal law the label is the legal instruction, and using a pesticide against it is illegal.
- Check the pre-harvest interval. Every product that’s cleared for an edible crop sets a minimum number of days between spraying and picking. Find it on the label before you spray anything you intend to eat.
- Check the re-entry interval before you or anyone else works in the treated area again, and use the protective equipment the label names.
- Confirm the product is registered for your crop in your state. This page groups many different crops together, and a product legal on one of them is not legal on all of them — state registrations differ too. Your state pesticide agency or local extension office can confirm both.
- Rates and mixing instructions come from the label, never from us. We don’t publish them because they differ by product and formulation.
Other problems on the same plants
If a plant gets fireblight, these are the problems it most often gets as well, so they are worth checking for while you are out there. They tend to appear together; one does not cause another.