They sell bean transplants?!?

I'm sorry, but garden centers are doing a great disservice to new gardeners by selling transplants of easy-sprouting but hard to transplant vegetables such as squash, melons, cucumbers, and, I guess, beans too.

All of these plants will sprout and grow enthusiastically when direct seeded -- assuming the ground is warm enough. None of them appreciate having their roots disturbed. :-(

I suspect that transplant shock weakened your plants so that the are succumbing to pests and diseases that stronger plants might have fought off.

Another possibility is that in your zone beans may not survive the summer heat. Here in zone 7 in NC beans should be planted in May and in late July with the expectation that the bush varieties at least will not survive the blistering heat of June and July.

Usually zones 10 and 9 in southern California have very cool springs and early summers, it does not get warm here until August usually. Right now it is really cool, almost cold (I live here too and we have been running the heater at home). Damage could not be from heat. I do agree with the previous poster on germination though, you are much better off buying seed for Kentucky wonder pole beans and planting directly. I have had good success with KW here too, so they will do fine for you. Also, once the seedlings recover from transplant shock they might produce well for you, good luck!

I sometimes plant a few beans close together to transplant into spaces where they didn't come up. I use a trowell and get lots of roots but they still take a week or more shock before starting to grow again. I do that with squash and okra too. If I get a good stand I just thin the few to good spacing.