I'm doing garden planning for next year and as part of that I'm trying to figure out why I've been getting black spots (with small divots) on the bean pods. There are enough of the black spots that the beans are pretty useless. I don't give my string beans very much attention, but I think that if I harvested them promptly or when they are smaller, it wouldn't be so bad. When I look at pictures on Google images, the damage looks a lot like the pictures of anthracnose. I use raised beds (shoveled up, with no side boards), lots of organic matter mixed with the high clay soil, and generally everything in my garden grows very vigorously. Anthracnose is evidently carried over in seed, but I do not save string bean seed. I do save dry bean seed, but have not noticed this problem in my dry beans. Do you have any ideas?

Thank you, Tim