Lima Beans Won’t Produce Seeds
I'm growing speckled pole limas in Gainesville, FL. They produced like crazy a couple years ago in a different part of town. They're inoculated with a garden combination mix in a strip of land where we dug out bahia grass and mixed in a little low-N horse manure.
I built a huge trellis for them, about 12 feet tall, and they swallowed the whole thing in a few weeks. They've been growing really well for months, look really healthy, but have yet to produce a single bean. We've been getting a lot of rain this summer. They look like they're enjoying it. The pods fall before they've grown much, and the few that stay on till they dry have stunted little beans in them.
I hear there's a boron deficiency in the area; could that be the cause? Cowpeas growing nearby are producing seeds if they escape the scythe long enough to flower (last year's cover crop came back. I'm letting them stay between the rows, but they keep trying to swallow my other crops, so I cut them back regularly. ).
It is possible that the soil has too much nitrogen, consider a soil test. Inquire about that at your local agricultural extension office, or at Department of Horticulture at the university.
If you are using saved seed, it could be possible that they got cross-pollinated last year with a low yielding legume of some sort. Just an idea...