Winged Bean Seeds - Asparagus Pea - Manilla Bean - Phosphocarpus tetragnolobus

6, 7, 8, 9, 10, 11, 12

USDA Zones 6-12: Grows as a tender tropical perennial in frost-free zones (10-12) and as a very long-season warm annual in zones 6-9. It is extremely sensitive to frost and requires a long, hot growing season.

Best Performance (Zones 9-12): Thrives in these zones with long, hot, and humid summers. The extended frost-free season allows the plant to reach maturity and produce heavily in the fall when the days shorten.

Northern Zones (6-8): Very challenging. While the plant will grow vigorously, its "short-day" nature means it will not flower until late August or September. You must start seeds indoors 6-8 weeks early and be prepared to protect the plants from the first fall frost to get a harvest.

Hot Climate Zones (9-12): This is its ideal climate. Plant in spring after all frost danger has passed, and it will flourish through the heat, providing a large harvest in the fall.

Soil Temperature: Requires very warm soil to germinate. The minimum soil temperature is 70 degrees F, with optimal germination occurring at 75-85 degrees F. Seeds will rot in cool, damp soil.

Growing Season: Requires a very long frost-free period (120-150+ days). More importantly, it is a short-day plant, meaning it needs the shortening days of fall to trigger flowering. Harvest typically does not begin until 5-6 months after planting.

Learn more about USDA Hardiness Zones here

When to Plant (Indoors):

Mandatory for Zones 6-8: Start seeds indoors 6-8 weeks before your average last frost date.

Use 4-inch biodegradable pots to avoid disturbing the sensitive roots when transplanting.

When to Plant (Outdoors):

For Zones 9-12: Direct sow seeds 2-4 weeks after all danger of frost has passed.

Critical: Wait until the soil is thoroughly and consistently warm—at least 70 degrees F.

Where to Plant:

Sunlight: Full, hot sun (8+ hours per day).

Trellis (Essential): You must provide a very tall (8-15 feet) and strong trellis, fence, or arbor at the time of planting. This vine is heavy and vigorous and will quickly overwhelm a small support.

Soil: Plant in rich, fertile, well-drained soil.

How to Plant:

Seed Prep (Critical): The seeds have a very hard coat.

Scarify: Gently nick the hard seed coat with a nail file or small clippers. Be careful not to damage the "eye" of the seed.

Soak: After nicking, soak the seeds in warm water for 12-24 hours. They should swell in size.

Depth: Plant the pre-soaked seeds 1 inch deep.

Spacing: Space plants 12 inches apart at the base of your trellis.

Germination: Keep the soil very warm and evenly moist. Germination can take 10-21 days.

Growing and Care:

Watering: Water deeply and consistently, especially during the extreme heat of summer.

Fertilizing: As a legume, it fixes its own nitrogen. Avoid high-nitrogen fertilizers. Amending the soil with compost and a phosphorus-rich fertilizer (like bone meal) at planting time is beneficial.

Patience: The plant will vine vigorously all summer. Do not panic if you see no flowers. Flowering is triggered by the shortening days of fall.

Harvesting:

Pods: Begin checking for pods 60-80 days after flowering begins. Harvest pods when they are young, tender, and 3-5 inches long. They become woody if left too long. Check plants daily, as they grow quickly.

Leaves & Flowers: Tender young leaves and flowers can be harvested sparingly throughout the season.

Roots: The tuberous roots (which have a nutty flavor) can be harvested at the end of the season by digging up the plant after the first frost.