How Long Do Asparagus Bean Vines Get?

About Asparagus Beans

• Related to Southern peas or cowpeas, asparagus or yard-long beans grown on long vines require sturdy support. While the beans do grow to a yard long, they are usually eaten when 10 to 12 inches and as thick as a pencil. The immature, tender pods can be snapped and cooked like green beans. If allowed to grow to full size, the beans inside should be shelled and cooked like cowpeas.

Vine Length

• Asparagus beans, a type of vining bean or pole bean, climb by means of twining tendrils that wrap around small supports such as stakes, wires or string. By summer's end the vines will be 8 to 12 feet long, so give them a tall trellis or pole to climb. The support should be at least 6 feet to adequately support the vine. Insert poles at intervals down the row and run wire or string between the poles or, alternatively, erect tripods made out of rough poles and plant beans at the bottom of each pole.

Asparagus Bean Culture

• Grow asparagus beans in full sun and rich garden soil suitable for regular green beans and other vegetables. Plant the seeds an inch deep and 8 to 12 inches apart. Space rows 2 to 4 feet apart. Install a trellis or other support when you plant the seeds, since once the beans sprout, they grow quickly. Beans need at least an inch of water a week, so supplemental watering is necessary during unusually dry, hot or windy weather. Water early in the day to allow the leaves to dry quickly, reducing the likelihood of disease. Ten- to 12-inch bean pods are ready to be harvested in 50 to 80 days, depending on your climate. Pick the beans often to prolong the harvest, which lasts for several weeks.

Season's End

• Asparagus beans grow on vines that reach 8 to 12 feet long by season's end. The beans themselves grow 10 to 36 inches long but are most tender at 10 to 12 inches long, according to the Texas A&M AgriLife Extension.