The limas will not cross except with other limas... and then, only if the other limas are flowering at the same time. If the Fordhooks flowered well after the BJBBs, then you have "time isolation" of the BJBB. Estimate the total days between the first blossoms of the two varieties, subtract about a week or two for a safety zone, and that's how long you should be able to harvest pure seed.

Two possible wrinkles: if you harvested the first pods that ripened, then that reduces the time that you can harvest pure seed. If in doubt, err on the side of caution, and harvest only the first dry seed. Based upon your description, it sounds like you may already have some pure seed.

The other possible problem is crossing from your neighbors. Limas are high-quality nectar sources, and bees can cross them from fairly long distances. I say this from experience. In my rural plot, the nearest garden is 1/4 mile away; and in my saved seed, only two things have ever crossed from the outside - squash and limas. If you think that you might have neighbors nearby growing butterbeans, then some crossing is possible. You can reduce the chances by saving seed from only the center plants in the row, or if in multiple rows, from the center row only.

You probably won't want to save seed from the Fordhook, since crosses are likely... but given that the dark color of the BJBBs is probably dominant, you might get some interesting results if you do.

You should be OK Cindy, or have something better?

Thank you Zeedman! This is just what I needed to hear - I figure I have another week or so of dry seed to harvest.

Yes, the limas just started to flower last Thursday or Friday, but I have been waiting on the BJBBs to be ready for several weeks now. I was surprised to find some dried seeds in pods in the inside of the cattle panel arch on Saturday. So we harvested a bunch of pods, still learning when they are "done". I have several dozen completely dried beans, some that are about half dry - sitting on paper towels, and the rest were fresh and eaten. There's more out there to be picked - guess what I'll do tomorrow. :-)

No one nearby is growing lima type beans. The only real gardener (1/3 mile) grows just green beans, tomatoes, squash, and peppers.

Another question - if I want to bag flowers with tulle - will the BJBBs pollinate themselves? Or do I need a paintbrush to play bee first?

Thank you Wertach! I'm excited to save seed in an organized fashion this year. So far I've only saved some peppers and tomatoes and various flower and herb seeds.

Cindy, I think you already have your answer. Your BJBB seed should all be pure.

Luther

Can I tell by the appearance of the BJBB seed whether it is a cross? Or do I need to grow out the seed and check the plant and seed produced? Apologise for what may be a dumb question - all my searching here has not found an answer.