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Brown leaves on a pear tree can be a minor cosmetic problem or the first sign of fire blight, one of the most serious diseases of pears. The way the browning shows up, whether it is whole shoots, spots or blisters, and when, usually points clearly to one cause.
The short answer: if whole shoot tips turn brown or black and bend over like a shepherd’s crook, suspect fire blight and prune it out promptly. Purple-black spots that start on the lowest leaves point to Fabraea leaf spot. Small blisters that turn brown are blister mites. Orange spots that later turn brown are pear rust. Crispy brown leaf edges in hot, dry weather are usually drought stress.
Match the pattern
| What you see | Likely cause | Urgency |
|---|---|---|
| Shoot tips and leaves blackened or brown, tip bent like a hook, leaves stay attached | Fire blight | High: prune soon |
| Small purple dots on lower leaves that grow into dark spots, leaves dropping | Fabraea leaf spot (leaf blight) | Moderate |
| Raised blisters 1/8 to 1/4 inch, green or reddish, turning brown to black | Pearleaf blister mite | Low to moderate |
| Bright orange spots on top of leaves, growths underneath | Pear rust | Moderate |
| Brown, crispy edges, worst on the sunny side, in hot or dry weather | Drought or leaf scorch | Moderate |
| Whole tree browning after root damage or construction | Root stress | High |
Fire blight
Fire blight is a bacterial disease of pears, apples and related plants. It thrives in warm, wet weather during and just after bloom. The University of Minnesota Extension describes the classic signs: blossoms and leaves wilt and turn brown to black, and infected shoot tips bend over into a shepherd’s crook. Dead leaves often stay on the branch, as if scorched by fire. Amber ooze may appear on infected shoots in wet weather.
What to do:
- Prune infected shoots well below the visible damage, roughly 8 to 12 inches into healthy wood, preferably during dry weather.
- Disinfect pruners between cuts.
- Avoid heavy nitrogen fertilizer, which drives the soft growth that fire blight infects most easily.
For a full guide, see how to treat pear tree fire blight.
Fabraea leaf spot
Penn State Extension describes this fungal disease, also called leaf blight and fruit spot. It starts as small purple dots on the leaves nearest the ground, which grow into purplish-black or brown spots with a tiny black pimple in the center. Heavy infections can defoliate a pear tree within a few weeks in wet seasons and also spot and crack the fruit.
The fungus overwinters on fallen leaves. Raking and removing leaves in fall, pruning for good air flow and avoiding overhead watering help. Penn State notes that in wet seasons, home and commercial growers often need fungicide protection through the summer, especially on late varieties such as Bosc.
Pearleaf blister mite
These microscopic mites overwinter under bud scales and feed on emerging leaves in spring. WSU HortSense describes pale green to reddish blisters, 1/8 to 1/4 inch across, that turn brown to black later in summer as the tissue dies. Heavy infestations can make leaves drop and leave russeted, sunken patches on the fruit.
Healthy trees tolerate light damage well. Predatory mites help keep blister mites in check, so avoid broad-spectrum insecticides that kill them. On small trees, picking off affected leaves can reduce numbers.
Pear rust
Pear rust, caused by fungi that alternate between pears and junipers, produces bright orange spots on the upper surface of leaves and growths on the underside. Infected leaves later turn brown and may drop. Read how to treat rust on pear trees for the full life cycle and control options.
Drought and leaf scorch
When roots cannot keep up with water loss on hot, windy days, the leaf edges brown and curl. Scorch is usually worst on the sunny, windward side and on the top of the tree. Newly planted trees are most at risk.
- Water deeply, soaking the root zone, every 7 to 10 days during dry weather.
- Apply 2 to 4 inches of mulch over the root zone, keeping it away from the trunk.
- Avoid heavy pruning or fertilizing a drought-stressed tree.
Ornamental pears
Callery pears, including Bradford, are ornamental, not fruiting, pears. NC State Extension notes they are generally pest-free but weak-wooded and invasive, and several states now restrict their sale. They can still get fire blight. If an ornamental pear is browning and breaking up, consider replacing it with a native tree rather than nursing it along.
When to call for help
If you see fire blight on a large tree, or if browning spreads quickly through the crown, a certified arborist can confirm the cause and handle pruning safely. Your county extension office or plant diagnostic lab can also identify samples. The ISA Find an Arborist directory lists certified professionals.
Not sure which pear you have? See what kind of pear tree you have.
Sources
- Fire Blight, University of Minnesota Extension
- Leaf and Fruit Spot of Pear in Home Gardens, Penn State Extension
- Pear: Pearleaf Blister Mite, WSU HortSense
- Callery Pear: Bradford Pear, Other Varieties, and Their Invasive Offspring, NC State Extension
Top photo: megachile, CC0, via Wikimedia Commons