Though advertised as a bush bean (Southern Exposure Seed Exchange), they'll vine when given the chance, and produce a bit more heavily. I grow them around the border of my garden, with sticks and bamboo stakes. The trick, I think, to harvesting them is to leave them until the individual peas are clearly defined and the hulls go every so slightly yellow--the peas are still green, and they slide out of the hull without a problem.
At the end of the season, I pick the last round to dry and use next year, and mow them down as green manure.
Here's the dish I made tonight, based roughly on a recipe from Ronni Lundy's excellent southern cuisine cookbook, From Butterbeans to Blackberries:
In a large kettle, cook two cups cowpeas until tender--about five minutes in heavily salted boiling water ought to do it. If you have a couple handfuls of young cowpeas (shell and all), pole beans, or yard-long beans handy, toss them in during the last minute or two.Eat at room temperature with a big plate of cornbread and a glass of bourbon. (I'm from Kentucky...)
Scoop the beans out with a slotted spoon, and toss in a half a pound of elbow macaroni. Cook until al dente, drain, and toss with a tablespoon of olive oil. Set all of this aside to cool.
Meanwhile, chop finely one large scallion and one rib of celery. (You could also use a sweet Italian pepper here, but not a green bell pepper, which even animals won't eat...)
Roast a large green tomato over an open flame on the end of a fork (as Luny puts it, like a marshmallow over a campfire), or broil/grill it until it's softened a bit and the skin is all black. (Failing either of these, a cast iron skillet over medium heat works, too.) When the tomato has cooled, peel it, but don't worry if there's still some charred skin. Chuck it in a blender, along with 1/4 cup olive oil, 1/2 cup plain yogurt (I prefer full fat), one medium garlic clove, and a heft amount of salt (at least a two teaspoons, but you go with your own preferences). Blend at high speed until very smooth.
Mix the yogurt dressing, the scallion and celery, and elbow mac and cowpeas together in a large bowl, and combine well. Taste, and add salt and pepper as needed. If things aren't zippy enough, consider a shot of red wine vinegar.
Really satisfying and easy vegetarian cooking. But I imagine it would complement some barbecued ribs, too.