85 Days to maturity. Vigna unguiculata var. sesquipedalis. Black Yard Long Asparagus Bean Vegetable Seeds. Non-GMO, annual, open-pollinated, pole bean seeds. Produces pods that can grow to be anywhere from one to three feet long. Often considered best between 10 and 20 inches long. Yard-long beans have a taste similar to that of a green bean. Popular ingredient in Asian stir fries and other vegetable dishes. Require support from a fence or pole so that their vines can grow up and provide the room necessary for the pods to grow to their full size. Black seeded.