Troubleshooting
Black Turtle Bean problems — and how to fix them
Black Turtle Bean (Phaseolus vulgaris 'Black Turtle') is generally forgiving once you match its basics, but a few issues come up again and again. Here is what each one looks like, why it happens, and the fix.
Anthracnose
Dark, sunken lesions on pods and seeds caused by Colletotrichum lindemuthianum. Use certified disease-free seed, rotate crops at least 3 years, and avoid working in the bean patch when foliage is wet.
Aphid infestations
Black bean aphids cluster on growing tips and undersides of leaves, causing curling and sooty mould. Knock off with a strong water jet; introduce ladybirds or apply insecticidal soap for heavy infestations.
Weevil damage in stored beans
Bean weevils (Acanthoscelides obtectus) infest stored dried beans. Freeze harvested beans at -18 °C for 48 hours to kill eggs, then store in airtight glass jars in a cool, dark location.
Prevent black turtle bean problems before they start
Most black turtle bean issues are care-mismatch, not bad luck. Dial in the basics:
Looking for black turtle bean in general rather than its problems? Read the full black turtle bean care guide — light, water, soil and feeding.
Black Turtle Bean problems — FAQ
Why is my black turtle bean anthracnose?
Dark, sunken lesions on pods and seeds caused by Colletotrichum lindemuthianum. Use certified disease-free seed, rotate crops at least 3 years, and avoid working in the bean patch when foliage is wet.
Why is my black turtle bean aphid infestations?
Black bean aphids cluster on growing tips and undersides of leaves, causing curling and sooty mould. Knock off with a strong water jet; introduce ladybirds or apply insecticidal soap for heavy infestations.
Why is my black turtle bean weevil damage in stored beans?
Bean weevils (Acanthoscelides obtectus) infest stored dried beans. Freeze harvested beans at -18 °C for 48 hours to kill eggs, then store in airtight glass jars in a cool, dark location.