Apple and pear scab
Olive-brown blotches on leaves followed by corky black scabs on the fruit. It looks alarming and is mostly cosmetic on the fruit; the real cost is repeated early leaf fall, which weakens the tree over years.
Caused by: Venturia inaequalis on apple and Venturia pyrina on pear · also called scab
Described view
Three apples on one surface with a scale reference: one split cleanly along a fresh crack with pale unblemished flesh showing, one carrying the corky olive-brown scab lesions that crack the skin as the fruit expands, and one with the concentric buff pustule rings of brown rot spreading from a wound
What brings it on
Wet spring weather. The fungus overwinters on fallen leaves and releases spores in spring rain, so a wet April is what decides how bad a year will be. Crowded, poorly ventilated trees stay wet longer and are hit harder.
source
Sourced guidancehigh confidence
- Royal Horticultural Society: Apple and pear scab
- Cornell Fruit Resources — Cornell University, College of Agriculture and Life Sciences: Apple scab — disease cycle
Checked 2026-08-13
Usually seen: April, May, June, July
Preventing it
Ordered by how much difference each measure actually makes, not by how often it is repeated.
- Choose a scab-resistant cultivar when planting. This is by far the most effective measure available and it can only be taken once, at purchase.
source
Sourced guidancehigh confidence
- Royal Horticultural Society: Scab-resistant apple cultivars
Checked 2026-08-13
- Clear and remove fallen leaves in autumn. The fungus overwinters on them, so removing them removes next spring's spore source.
source
Sourced guidancehigh confidence
- Cornell Fruit Resources — Cornell University, College of Agriculture and Life Sciences: Apple scab — sanitation
Checked 2026-08-13
- Prune to keep the centre of the tree open so foliage dries quickly after rain.
source
Sourced guidancehigh confidence
- Royal Horticultural Society: Apple pruning — established trees
Checked 2026-08-13
Dealing with it once it is there
- Remove badly affected shoots in winter, where scab has produced blistered cracked bark on young growth.
source
Horticultural consensusmoderate confidence
- Royal Horticultural Society: Apple and pear scab
Checked 2026-08-13
- Scabbed fruit is edible. Cut the marks out and use it — a scabby crop is a cosmetic disappointment, not a loss, and treating it as one avoids reaching for sprays that would not have worked anyway.
source
GrowingHQ editorial positionmoderate confidence
A judgement about proportion rather than a claim about the fungus. Stated because the appearance of scab prompts more intervention than its actual cost justifies.
- GrowingHQ editorial synthesis — GrowingHQ
Checked 2026-08-13
Widely repeated, and not supported
Recorded so GrowingHQ can address them. These are not alternative approaches — they are things the evidence does not back.
“Scab can be cleared up by spraying once it appears on the fruit.”
By the time scabs are visible on fruit the infection happened weeks earlier, during spring rain. Everything that changes the outcome — cultivar choice, leaf clearance, airflow — happens before symptoms appear.
Horticultural consensusCommonly said, not supportedmoderate confidence
- Royal Horticultural Society: Apple and pear scab
Checked 2026-08-13
What it affects
On sprays and treatments
GrowingHQ does not tell anyone what to apply, at what rate, or how often. Pesticide approvals differ by country, change without notice, and the product label is legally binding — it is also the document you are holding. What is described here is cultural and physical control, which is what a home grower can act on without a label in front of them.
Plant-specific guides
Where this is one of several causes that look alike on a particular plant, GrowingHQ publishes the differential rather than the general answer.