Apple Scab
Disease · Commonly affects: Apple trees, Crab apples, Pear trees, Ornamental pears, Quince, Medlar
Apple scab is a fungal disease of apples, pears and related ornamental trees. Damp spring weather encourages infection of fresh leaves and developing fruit, making it especially familiar in British gardens. It rarely kills a mature tree, but repeated attacks weaken it, spoil crops and make stored fruit more likely to deteriorate.
How to identify it
On young leaves, look for velvety olive-green patches that later turn brown or black and may become puckered. Similar blotches can form on leaf stalks and young shoots. Fruit develops dark, rough, corky scabs, often 2-20 mm wide, which may crack as it enlarges. On pears the marks are often darker and more defined. Symptoms are usually most obvious after wet spells in spring and early summer, particularly within dense, poorly aired canopies.
Damage
Badly affected leaves may yellow and fall early, reducing the tree's vigour. Fruit remains edible if lightly marked, but severe corky lesions distort growth, split the skin and reduce keeping quality. Repeated infection reduces cropping and allows the disease to build up in fallen leaves, making future wet springs more troublesome.
Prevention
Choose scab-resistant apple and pear varieties where possible, especially for a small garden with little room for spraying or intensive care. Rake up fallen leaves and spoiled fruit in autumn, then bin them or send them in green-waste collections. Prune in the dormant season to create an open canopy with good airflow. Water at soil level rather than wetting foliage, avoid overcrowding beneath trees and maintain steady nutrition without excessive nitrogen-rich feeding.
How to manage it
Pick fruit carefully as it ripens and remove badly scarred, split or rotting fruit promptly. During winter, clear remaining leaves and mummified fruit from beneath and within the tree. Prune out congested twigs and crossing branches to help foliage dry quickly after rain. In a young tree, remove heavily affected leaves only if enough healthy foliage remains. If scab is persistent, replace a severely susceptible tree with a resistant variety rather than relying on repeated treatments.
Apple Scab: frequently asked questions
How do I identify apple scab?
On young leaves, look for velvety olive-green patches that later turn brown or black and may become puckered.
How do I prevent apple scab?
Choose scab-resistant apple and pear varieties where possible, especially for a small garden with little room for spraying or intensive care.
How do I get rid of apple scab?
Pick fruit carefully as it ripens and remove badly scarred, split or rotting fruit promptly.
General guidance for UK home gardens and allotments, focused on prevention and non-chemical control. For a confirmed diagnosis, the RHS or a local garden centre can help. Page updated 19 Sep 2026.