MG Volunteer: “OSU Extension Master Gardener volunteer. How may I help you?”

Caller: My peach tree is not looking happy. It’s early March, and the new leaves are yellow to reddish and curled up - kind of distorted looking. Then some are dropping off.
MGV: When did these symptoms appear?
Caller: As soon as the leaf buds were opening.
MGV: Is the whole tree affected?
Caller: Yes, most of it, although some branches more than others. Gradually more leaves are turning dark brown and falling off.
MGV: Are the leaves the only part affected?
Caller: No, the blossoms and fruit and a few twigs are also distorted and some fruit have reddish growths on them.
MGV: Have you noticed any insects or mites on the tree?
Caller: No

Diagnosis:

Peach Leaf Curl: The cause is Taphrina deformans, a fungus. It causes severe leaf malformation and leaf drop. Many infected fruit drop early. Spores overwinter on bark, twigs, and old infected leaves and often appear as a dusty white coating. Infection occurs through bud scales in mid- to late winter just as buds begin to swell or on slow growing shoots and leaves during a cool and wet growing season. Maximum susceptibility is between bud break and petal fall. More information is available at this website.

Recommendations:

Cultural: Remove all fallen infected leaves. Plant a curl resistant tree such as: 'Autumn Rose,' 'August Etter,' 'Avalon,' 'Avalon Pride,' 'Charlotte,' 'Early Charlotte,' 'Early Crawford,' 'Frost,' 'Indian Free,' 'Kreibich,' 'Muir,' 'Nanaimo,' 'Oregon Curl Free' and 'Q-1-8.'

Chemical: Two fungicide applications are recommended for western Oregon: at 50% leaf fall (late October), and again at delayed dormant (usually in late February, before floral buds open). Refer to PNW for specific information.

(Thanks to the Benton County Master Gardeners for developing this scenario)