Pros: Easy to grow. Pretty flowers, pods, and beans. Retains its shape after cooking.
Cons: Unremarkable, but also unobjectionable, flavor.
My first ever attempt at growing soup beans was practiced last year on the heirloom Cherokee Trail of Tears bean. This variety has been given a ticket for the Ark of Food by the Slow Food organization. Vegetables included in the Ark are recognized as of cultural and culinary significance, as well as being "endangered" vegetable specimen. These beans were carried by the Cherokee nation during the ethnic cleansing campaign carried out against them in 1838.
These black beans have a glossy, jet black skin and an elongated kidney bean shape. When freshly harvested, they are so shiny they look as though they've been coated with oil. I planted one packet's worth of these beans and was rewarded with about three pints of harvested crop. The small pink-purple flowers on the vine added some nice color to the vegetable garden, and the vines bloomed almost continuously over the summer and early fall months. Most but not all of the seed pods turned a gorgeous deep purple after an initial green coloration, and then dried down to a medium tan-brown on the stalk. While the bulk of the crop ripened and dried down by late summer, this was followed by another round of blooms and smaller pods. By that time, fall was coming on in earnest, and the pods were fewer and smaller. But if I lived in a warmer climate, I might have had a significant second crop.
I think I might also have seen a larger harvest if I had provided a longer vertical climb for these beans. I gave them only about three feet of trellis to climb in most places. But a few of the Cherokee Trail of Tears beans found my sunflowers, and up, up, up they went. This year I plan to give them a lot of length to climb, which I suspect will suit them better.
I found that presprouting the beans worked well for me last year. Once the little tail emerged, the sprouts were ready to go into the ground, though they were also a little fragile. I saw an excellent germination rate, possibly even 100%. The transplants did very nearly as well. If there were any pests on these beans, I sure didn't notice them, nor did they adversely affect the quality of the beans I gathered. I did companion plant most of my beans alongside my heirloom potatoes, as recommended by the book, Great Garden Companions. But I believe this pairing is recommended mostly to allow the nitrogen-fixing bean roots to benefit the potatoes.
We've enjoyed the Cherokee Trail of Tears beans over the winter months in burritos, bean soups, and chili. They have cooked up very easily and quickly, perhaps because they are very fresh by the standards of dried beans. I found that the beans retained their shape rather well and didn't spill very much starch into the cooking liquid. When I wanted a thicker texture, I just removed some of the beans from the liquid and mashed them with a fork. While it's nice to have a thick and starchy bean soup sometimes, I like a bean that retains its integrity, thus giving me better control over the consistency of the soup.
Taste-wise I can't say that the Cherokee Trail of Tears bean is remarkable. But then I've honestly not noticed a huge range of flavors inherent in soup beans, properly speaking. No doubt this has something to do with the propensity of beans to absorb the flavors of whatever flavorful ingredients they are cooked with. While I can tell the difference between a kidney bean and a chickpea. I doubt I could easily distinguish, by taste alone, between a navy bean and a pinto. Still, I am growing the Cherokee Trail of Tears again this year, and I have saved a few of the beans from last year to bolster the new packet I got this year.
As a trial run for a novice bean grower, the Trail of Tears bean did extremely well for me. I don't know if all soup beans are this easy to grow, but I would certainly recommend the variety to anyone in a similar position of interest coupled with inexperience.