Out of my desire to save seeds from my vegetable garden, I have begun buying Open Pollinated (OP) Heirloom seeds. OP varieties generally grow true from home-saved seed, although some may cross-pollinate with a similar neighboring plant. (Peppers, or squash and pumpkins are notorious for cross-pollinating.) Saving seeds from any hybrids you grow could result in sterile seeds, or seeds that grow a strange offshoot from one of its parents, but not be the same as what you grew and liked. Another factor for me was that OP seeds are tried and true, some going back a century, others far longer, and most do not have fussy growing requirements.
This year I ordered the OP Kentucky Wonder pole bean (Phaseolus vulgaris) to try; it has a good reputation and is widely available. My seeds came from Victory Seeds but there are many good vendors. I chose this bean based on all the favorable comments, and the fact that it has been around since the Civil War. This bean reportedly was first known as ‘Texas Pole’, ‘Southern Prolific’ and ‘Old Homestead’ before being named ‘Kentucky Wonder’ in the late 1800’s. It is considered one of the 2 most popular pole beans, the other being Blue Lake.
“What made the 'Kentucky Wonder' a wonder was, in part, its size. The beans were extraordinarily long. Even specimens up to nine inches long were still tender, brittle, and free from fiber, three qualities of first-rate green beans. What also made this bean a wonder was its distinctive (and delicious) flavor.” 
Reports about the flavor were NOT wrong! I have never before tasted such a delicious green bean, and as much as I love my skinny French Haricot Verts , they do not begin to approach the flavor of the Kentucky Wonders. So far, I have only eaten this “Wonder” bean freshly cooked but I’m told the mature beans, after shelling or drying, are equally tasty. I just snapped a batch today to blanch and freeze; I have already canned 24 pints of them, and my 8 (only!) vines are still flowering and producing. Unlike bush beans, which produce their crop all at once, I understand these beans will flower and produce until frost as long as I keep them picked.
Most of the vendors say this bean grows 6-8’ tall. My cattle-panel trellis is 9’ tall and the beans exceed that height as much as 18”; I have to use a ladder to pick the top beans! They have not been fertilized either, just planted where I had tomatoes in straw bales last summer. The seeds can be direct sown, about 1-1/2” deep with rows 3’ feet apart. However, I started mine in flats because the ground was still cold, and gave half of the seedlings away. The vines grow very thick and sturdy so they need a strong trellis. Most teepee (tripod) type supports like I have for my other beans are not suitable. (In fact, they not suitable for my other variety either, but I’m learning.) Both pole bean types I’m growing produce most of their beans near the top. Teepees, even though they are so cool-looking in the garden, are not very useful for pole beans since there’s not much room at the top. Kentucky Wonders need ample sunshine on their leaves for a good crop, so they shouldn’t be crowded.
Bamboo Tripods/Teepees Beans on Teepees Beans climbing
The only pest problem I have with this bean is Japanese Beetles, but my cannellini beans and my raspberry plants have the same problem. Kentucky Wonders are pretty rust resistant; I have seen almost none on the long silvery-green pods that I have picked. I have (mentally) marked all the remaining pods growing lower than my shoulders as those to leave to mature and dry on the vine. I will have ample light brown bean seeds to trade with enough to grow in my garden next year. In the photos below, you can see some beans drying on the vines, and a few already shelled. The whiteish shelled beans have just been shelled; they shrink and darken as they dry. I will definitely be growing these "Wonders" again!
Lists of Some Merchants and Purveyors of Heirloom Seeds
Kentucky Wonder Green Beans Recipe
8 slices lean bacon, cut into 1/2-inch dice
1 cup scallion rounds, thinly sliced
2 pounds Kentucky Wonders, washed, the ends snapped, and the strings removed
2 tablespoons cold water
2 teaspoons salt
1/2 teaspoon black pepper, freshly ground
3 teaspoons red wine vinegar
3 tablespoons fresh thyme leaves, chopped finely
Fry the bacon in a large skillet, turning the pieces frequently until brown and crisp. Place bacon on a paper towel to drain. Sauté the scallions in the bacon fat, stirring occasionally. Cook scallions over medium heat for 3 to 4 minutes, until they are soft but not brown. Add the beans to the skillet, stirring them until they are well-coated with the bacon fat.
Add the water and cover the pan tightly. Cook over low heat for 5 minutes, then uncover the pan and continue to cook until the beans are tender but still slightly crisp, about 10 to 15 minutes. Stir occasionally. Sprinkle the beans with the salt and pepper, stir in the vinegar, and remove from the heat. Place beans in a serving dish, crumble the bacon and sprinkle the beans with the bacon pieces and chopped thyme.
Note: The above recipe is NOT the typical Southern recipe. As a southerner, I usually cook the beans in a pot of water (just enough to cover) with crispy salt pork or bacon, plus salt and freshly ground pepper to taste. Sometimes I add sautéed onions, and then cook until the beans are very tender. Yummy with fresh hot buttered cornbread!
For another article on green beans (and a great recipe), see Snap Beans: A Summer Garden Delight