Posted by oakandsage on July 05, 2013 at 19:40

I have been assuming that the beans growing in my garden (that are finally taking off and seem healthy, Y A Y) are yard long beans because they match the picture on the package, and I want yard long beans. But recently (partly because the immature pods are getting thicker but not getting longer, at least not yet) it occurred to me that I planted black-eyed peas as an afterthought and I'm not sure what they look like.

I looked them up and they looked just the same. I spent some time trying to find an identifying difference other than the mature fruit. But the leaves look the same, the flowers look the same, the immature fruit look the same! It seems the flowers can be yellow or purple for both. I started wondering if they're related.

Then I noticed the scientific name.

Yard long beans are Vigna unguiculata sesquipedalis. Black-eyed peas are Vigna unguiculata unguiculata. They're the same species, different subspecies.

In contrast, most snap and dry beans are Phaseolus vulgaris. (Runner beans are Phaseolus coccineus. Limas are Phaseolus lunatus. Fava beans are Vicia faba, and of course soy is Glycine max.)

So that answers that. I guess the bad news is I won't know which I'm growing until the pods are closer to mature, but the good news is if they're black-eyed peas, I can use the immature pods in any recipe that calls for yard-long beans, and get the mature crop too if I don't go too crazy with the young pods. I guess that means that the black-eyes would be more versatile so maybe I should be hoping that's what I have! Or some of each, that would be good too.

I guess it also means if some of each did come up, I'd better not save seeds, unless I want to grow something weird.

Whether black-eyed peas or yard-long beans, I hope these do well because brief research shows that V. unguiculata (referred to as a group as cowpeas) is a great crop. Cowpeas love hot weather, and do well in part shade. Next year I want to grow some 3 sisters plantings at the top of the hill where the corn will provide evening shade for the tomatoes without blocking the morning sun; if I can't get my hands on some rattlesnake beans for the purpose, cowpeas would probably be a good alternative. And of course I always need plants to grow on the shade trellises, though I'd prefer something that was further along by this time of year. They're nitrogen-fixing of course, and not only are the pods a versatile food resource with lots of use in asian cuisine, but the young leaves are useful as a cooked green - very nutritious and high in protein. No wonder the earwigs went crazy on them during the spring!

As a side note - Although I inoculate all my legumes before planting, it seems that the Vignas that are doing well are the ones that I planted in potting soil and are receiving regular feeding (because they're growing with melons and I have to feed the melons). So that's weird.