These bush green beans have been champs, continually producing even though they look like they should die (and it's mid-August in Zone 5, having had some massively warm spells).
However they have looked like this for a long time now, but they keep flowering and producing - we've gotten about 20 pounds of beans from ~20 linear feet of them.
Is this something that is common to beans? Or is this just them trying to die due to heat? I understand beans aren't exactly all-summer producers normally.
There are lots of questions for you to answer to be able to pin point your problems. What I am seeing is fungus amongus. That means too much water and too much water too late in the day. You've also got a mulch that will harbor moisture and insects.
What have you done for fertilizer? I am glad you've gotten produce but I know these plants could have done better. Do you have a magnifying glass? Please look beneath the leaves for tiny insects. Are any of the leaves showing holes? Is this bed indoors? Greenhouse? Or are they in the out of doors garden? Has it been raining a lot? What was grown in this soil last year? What species of bean exactly? When did they start looking like this?
It could be spider mites(could be), leaf blight(might not be), anthracnose(possibly), bean rust(unlikely), mosaic virus(unlikely again) all of these have similar appearances- I would out of them go for anthracnose (fungus)- due to damp warm conditions and I would recommend removing all affected plants as and when possible- there is no cure for this and with extra care (remove all dead leaves) next season shouldn't reappear- keeping ones site tidy is probably the best way to avoid this occurring again.
