How do I treat anthracnose?

Pick fruit as soon as it ripens rather than leaving it on the plant. Remove and bin affected fruit — do not compost.

Will anthracnose spread to my other plants?

Yes. Anthracnose spreads, so deal with affected material promptly and keep it out of the compost.

Anthracnose

Q: What causes anthracnose?

Anthracnose is fungal disease. Anthracnose is mostly a fruit-rotting disease in the vegetable garden and a leaf disease on trees. On tomatoes it shows up on ripe fruit as sunken circles, usually on fruit that has been left on the plant too long in wet weather. On shade trees it causes early leaf drop in wet springs and matters far less than it looks.

Treatable

Fungal disease · spreads to other plants

Anthracnose is mostly a fruit-rotting disease in the vegetable garden and a leaf disease on trees. On tomatoes it shows up on ripe fruit as sunken circles, usually on fruit that has been left on the plant too long in wet weather. On shade trees it causes early leaf drop in wet springs and matters far less than it looks.

What it looks like

On fruit, circular sunken spots that darken and develop concentric rings of tiny black dots, often with a pinkish spore ooze in wet weather. On leaves, irregular brown blotches that frequently follow the veins.

How to confirm it

Sunken circular lesions on ripe fruit that deepen over days.
Pinkish or salmon-coloured spore masses in the centre in humid conditions.
On trees, brown blotches following the leaf veins, with early leaf drop in wet springs.
Attacks ripe fruit much more than green.

What to do

1Pick fruit as soon as it ripens rather than leaving it on the plant.
2Remove and bin affected fruit — do not compost.
3On trees, rake and remove fallen leaves. No spraying is warranted for a mature tree.

What it gets confused with

One observation settles each of these.

Blossom end rot →

Blossom end rot is always at the flower end and appears on green fruit. Anthracnose can be anywhere and prefers ripe fruit.

Early blight fruit rot →

Early blight fruit lesions form at the stem end where the calyx attaches.

Preventing it next time

Mulch and stake so fruit never touches soil.
Harvest promptly and avoid working among wet plants.
Rotate away from the same family for two years.

Plants affected

Tomato Beans Cucumber Maple & Shade Trees Apple & Pear

Check these two things first

Push a finger into the soil, two knuckles deep. Wet soil plus a wilting plant means too much water, not too little — and it is the commonest reason a plant is dying. Dry soil plus crisp leaves means the opposite. The leaves look nearly identical either way, so the soil is what tells you.
Turn a damaged leaf over. Half of all diagnoses live on the underside: fuzz means downy mildew, fine webbing means spider mites, clusters of insects mean aphids. Nothing on the top of a leaf is as informative.

Most garden problems are cosmetic and resolve without treatment. Reach for a spray last, not first.

Not sure it is anthracnose? Run the diagnostic key →