Almond Tree Diseases and Pests: Leaf Curl, Shot Hole and More

Most almond diseases strike in wet springs, during and after bloom, so they are worse in humid climates than in dry California summers. The usual pests are aphids, mites and nut-boring caterpillars. Good airflow, dormant sprays at the right time and orchard hygiene prevent most problems.

Diseases

• Peach leaf curl (Taphrina deformans): red, puckered, thickened spring leaves that drop. Spray copper or another approved fungicide in late autumn after leaf fall and again before bud swell.
• Shot hole: small purple spots that fall out, leaving holes in leaves; also spots on fruit. Copper or fungicide sprays in wet springs; avoid wetting leaves.
• Brown rot / blossom blight (Monilinia): flowers and shoots turn brown and die, with gum at the base. Fungicide at bloom in wet years; prune out blighted twigs.
• Red leaf blotch (Polystigma): yellow to red-orange blotches on leaves in summer, common in Mediterranean Europe.
• Hull rot: hulls rot and shoots die near harvest; linked to over-watering and excess nitrogen.
• Gummosis and cankers: amber gum from the trunk or branches, from fungal cankers, borers, sunburn or stress.
• Crown and root rot: in waterlogged soils.

Pests

• Aphids: curled young leaves in spring; usually controlled by ladybirds.
• Spider mites: speckled, bronzed leaves in hot, dusty summers.
• Peach twig borer: shoot tips wilt in spring; larvae bore into nuts.
• Navel orangeworm (California): larvae feed inside nuts; remove leftover "mummy" nuts in winter and harvest promptly.
• Almond wasp (Mediterranean, Middle East): larvae eat the kernel inside green nuts.
• Birds and squirrels: a major garden problem near harvest.

Prevention

• Plant in full sun with good airflow.
• Avoid sprinklers wetting the canopy.
• Remove mummy nuts and blighted twigs in winter.
• Apply dormant copper or approved sprays at leaf fall and before bloom.

More Almond Tree Guides

• How to Grow Almond Trees: The Complete Guide
• Why an almond tree isn't producing
• When and how to harvest almonds
• How to store almonds

Frequently Asked Questions

Why are my almond tree leaves curling and red?

Almost always peach leaf curl, a fungal disease of wet springs.

What causes holes in almond leaves?

Usually shot hole disease.

Why is my almond tree oozing sap?

Gumming can come from cankers, borers, sunburn or water stress; inspect the bark around the gum.