Peach leaf curl

Taphrina deformans

Red, blistered, curled leaves on peaches and nectarines in spring, from a rain-splashed fungus. Shelter trees from winter rain and remove affected leaves as they appear.

Fungus Serious Rain splashAirborne spores Spreads to neighbors

What you'll see

Leaves emerge thickened, puckered and curled, with raised red or crimson blisters.
The swollen areas turn a dusty white as the fungus produces spores on the surface.
Affected leaves then brown and fall, often stripping the tree by early summer.
A second, usually clean, flush of leaves follows, which is why the tree does not die.
Repeated years leave the tree weak, with poor fruit set and shoots dying back.

Why it happens

A fungus that overwinters as spores in bud scales, in bark crevices and on the twigs. In late winter and early spring, rain splashes those spores into the swelling buds, and the fungus infects the leaf before it has even opened. Nothing you do after the leaves emerge will undo the infection already inside them.

Cool, wet weather between leaf fall and bud burst, especially prolonged rain in February and March at temperatures below about 16°C. Trees on open walls in a wet region are hit hardest; those under an overhang or under glass often escape entirely.

Treating it

Pick off affected leaves as soon as you see them, before the white bloom of spores forms, and bin them.
Sweep up and remove fallen leaves so they cannot return spores to the tree.
Feed and water the tree well and mulch it, so the second flush of leaves comes strongly.
Thin the fruit on a weakened tree so it can put its energy into recovering.
A copper-based fungicide applied at leaf fall and again just before bud burst gives some protection, but shelter works better.

Keeping it away

Rig a temporary polythene or clear corrugated shelter over wall-trained trees from January to May, open at the sides for pollinators.
Grow peaches and nectarines under glass, or in a pot that can be moved under cover for winter.
Choose more resistant cultivars, such as the Avalon Pride peach.
Keep the tree in good heart with mulch and a spring feed so it shrugs off a bad year.
Clear fallen leaves each autumn and prune to keep the crown open and quick-drying.

Who gets it

Peaches and nectarines above all, with almonds and occasionally apricots and ornamental almonds affected.