Shot hole

What you see

Small reddish-purple spots on the leaves whose centres dry, die and fall out, leaving the leaf riddled with clean round holes as though hit with birdshot. Buds and twigs can develop dark sunken cankers that ooze gum.

Conditions

Wet, mild winters and springs with prolonged leaf wetness - very much a coastal Portuguese pattern. Spores overwinter in infected buds and twig lesions.

Treatment

Prune out cankered and gummy twigs in dry weather. Copper at leaf fall and again at bud swell is the standard, effective timing. Mid-season spraying does little.

Prevention

Improve airflow through the canopy. Avoid overhead irrigation. Clear fallen leaves. Keep the tree unstressed - drought-stressed almonds and apricots suffer worst.

Months: November, December, January, February, March, April

Plants

Peach, Nectarine, Almond, Apricot, Plum, Cherry

Remedies

Bordeaux mixture (copper)

The thing people get wrong

The holes look dramatic and gardeners spray in June when they finally notice them - by which time the infection is months old and the season is lost either way. This is a winter disease treated in winter: copper at leaf fall and again as the buds swell. Spraying a holed leaf in summer is treating a scar.