Why Are There Brown or Dark Spots on My Pea Pods?

Dark brown or purple-brown spots appearing on pea pods are most commonly caused by ascochyta blight — a complex of three fungal species (Ascochyta pisi, Mycosphaerella pinodes, and Phoma medicaginis var. pinodella) that attack pea leaves, stems, and pods during wet spring weather. The spots can range from small, well-defined dark marks to large, spreading lesions that cover significant areas of the pod. A secondary question whenever pod spots appear is whether the peas inside are still edible — in most cases with limited external spotting, they are.

Identifying ascochyta blight

Ascochyta spots on pods are typically circular to oval, dark brown to purple-brown, with a slightly sunken surface and sometimes a paler or tan centre. In severe infections, spots coalesce to cover large areas of the pod surface and the pod may wrinkle and distort. The same disease causes similar spots on leaves (brown with darker margins) and dark, girdling lesions at the base of the stem that can cause collapse of young plants. Wet, cool spring weather with heavy rainfall promotes ascochyta infection, and the spores are seed-borne as well as soil-borne.

Are spotted pods edible?

Yes, in most cases. The fungus attacks the pod wall but does not typically penetrate into well-formed peas unless the infection is very severe and the pods have been diseased from an early stage. Open a spotted pod — healthy, plump, green peas inside are perfectly safe to eat and will taste normal. Discard any individual peas that show discolouration or soft patches, but the rest of the pod's contents are fine. Very severely infected pods where peas inside are also discoloured or shrivelled should be discarded whole and the plants removed.

Prevention for next season

Ascochyta blight overwinters in infected plant debris left in the soil and is also carried on saved seed. Removing and composting (or burning) all pea plant material at the end of the season reduces the soil inoculum load significantly. Buying fresh seed from a reputable supplier rather than saving seed from affected plants breaks the seed-borne cycle. Rotating peas to a different area on a minimum three-year cycle prevents build-up. Choose ascochyta-resistant varieties where available — these are noted in seed catalogues and perform significantly better in wet seasons.