My area gets heavy summer rains, peak summer temps into the 90s F and occasionally 100s F, and high humidity during the growing season and I still get excellent bush dry bean harvests every year.
First thing I do is hill the plants/rows as the plants size up to help keep them upright. This only helps for around a month or so until the plants get too big and weighty, but the point is to keep them properly trained and growing upright for the next step.
When plants start to flop over meaning the soil hilling is no longer working then the second thing I do is sandwich or trap the plants in the rows with horizontal strips of
wood screwed to stakes. Does not need to be heavy duty, my homemade horizontal runners are 1/2" x 1 1/2" x 12' long ripped from 2" x 8"s or whatever I have around. I stake every five feet. The horizontals are usually located 10"-12" above soil surface. This keeps the plants and pods off the ground for the remainder of the growing season. Wish I had a photo of this but I don't. I do all this set up work by myself, not that hard to do and does not take much time, but a helper would make it easier.
Third and perhaps most important thing I do is harvest pods as they mature and dry down on the plants, usually every 4-5 days or certainly just before the next rain event. If I do not do this, thinking I can just harvest all at once at the end of the season, many of my beans will be moldy or rotten and I will suffer a high loss rate due to
mice and
voles.
Doing these three things consistently assure me a successful harvest. My average annual harvest is around 3-5 gallons of cleaned bush dry beans. I grow other dry bean types as well to hedge my bets (semi vining, half runner, standard pole, tall pole).
I also grow my own
landrace bush dry beans, which have been locally acclimated and are inherently more vigorous and disease resistant.
Photo shows my
landrace bush dry beans that went into my food supply: