Yardlong beans arose in Africa, and were domesticated in Asia. Their ability to thrive in sandy soils with low moisture made them an important crop in hot arid regions. They do not tolerate cold, so be sure and plant in warm soil – above 65 degrees. Plant 1 inch deep, and 4 to 5 inches apart. The vines grow up to 3 feet and do best on a trellis. Yardlong beans can reach 25 inches, but they taste better when harvested at 19 inches. Unlike green beans, the tender, stringless pods taste the best when sauteed, stir-fried, or deep-fried. Harvest in 70 to 80 days.