Plant library · Vegetables
Vigna unguiculata subsp. sesquipedalis
Yardlong bean is a heat-loving annual pole bean grown for its long summer pods. Its 10-foot vines turn a narrow planting strip into a vertical crop, while the foliage and pods occupy roughly 18 inches of width at maturity. Give it a tall trellis from the outset and reserve the sunny side for easy picking. Harvest begins around 75 days from planting and can continue from summer into early fall.
Place yardlong bean along a fence, trellis, or sturdy vertical frame at the back or edge of a vegetable bed rather than in the middle of a low planting. Set the support before sowing so young vines can be guided upward without disturbing their roots. A row beside a path works well when the trellis faces the access side, keeping developing pods within reach instead of hanging into neighboring crops. Keep its tall canopy from shading shorter sun-loving vegetables.
Plant 6 inches apart, center to center, to make a continuous climbing row. Although each plant matures only about 18 inches wide, the vines need their own vertical lanes on the support; avoid crowding them against another trellised crop. Allow a clear picking strip beside the row, especially where the support meets a bed edge, so vines and hanging pods do not spill across a path.
Use a full-sun position that warms quickly in summer, ideally with shelter from cool exposure. Keep soil evenly moist as plants flower and set pods, but arrange the bed so excess water drains away; waterlogged ground and flooding can damage the crop. Warm soil is important for germination, so this vine belongs in the summer portion of the vegetable plan rather than an early, cold-season opening.[1][2]
This crop occupies its trellis for one growing season, so treat the support as a summer-to-early-fall feature in the plan. Its flowers appear in summer, followed by pods through early fall. Remove the finished vines when the harvest ends to reopen the vertical space for the next crop or for winter access and bed preparation.
Do not site yardlong bean where frost is likely to catch newly planted vines or where standing water collects after rain. If pods are allowed to mature and drop seed, volunteer seedlings may appear in later plantings. Keep the trellis contained within the bed footprint, since a scrambling annual can become difficult to manage when it reaches across adjacent crops or circulation space.[1]
Editorial content updated 2026-07-20.