Garden Scheme
Plan your garden to scale — free, with 700+ plants Open the planner

Plant library  ·  Vegetables

Yardlong Bean

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.

Sunlight Full Sun
Water Moderate
Planning spacing 0.5 ft
Typical mature size 10 ft tall, 1.5 ft wide
Typical bloom Summer

Yardlong Bean spacing and mature footprint

Space Yardlong Bean 6 inches apart, measured center to center (15 cm).

The mature spread is about 18 inches (45 cm), so plants set at that distance grow together into a closed canopy over the bed.

Treat 6 inches as a planning baseline — cultivar and local growing conditions shift the final footprint.

Compare with the full vegetable spacing chart

Three plants set 0.5 ft apart, center to center; shaded circles show the 1.5 ft mature spread.

Placement and use

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.

Spacing and mature footprint

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.

Sun, water, and soil

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]

Seasonal notes

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.

Planning caveats

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]

Growing facts

Botanical name
Vigna unguiculata subsp. sesquipedalis
Type
Vegetable
Category
Vegetables
Lifecycle
annual
Sunlight
Full Sun
Water
Moderate
Planning spacing
0.5 ft
Typical mature size
10 ft tall, 1.5 ft wide
Typical days to maturity
About 75
Typical bloom season
Summer
Typical harvest season
Summer - early fall
Plan a garden with yardlong bean

References

  1. Long Bean - Vigna unguiculata — North Carolina Extension Gardener Plant Toolbox
  2. Vigna unguiculata subsp. sesquipedalis 'Green Noodle' — Royal Horticultural Society