How to Grow Yard Long Bean Purple Queen
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Yard Long Bean Purple Queen
Vigna unguiculata subsp. sesquipedalis
vegetablePurple Queen is a vigorous, pole-type variety of yard long bean (asparagus bean) that produces abundant 12-16 inch dark purple pods with excellent flavor. This heat-loving Asian vegetable grows on climbing vines and thrives in warm seasons, offering continuous harvests throughout summer and fall. The pods turn green when cooked and have a tender texture ideal for stir-fries and Asian cuisine.
When should you plant Yard Long Bean Purple Queen in your zone?
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Example Yard Long Bean Purple Queen timeline · Pittsburgh, PA (Zone 6b)
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Plant Yard Long Bean Purple Queen
Around Apr 17Near Pittsburgh's average last spring frost.
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Tend & protect
Late spring–summerWatering, feeding, and pest-watch reminders.
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Harvest Yard Long Bean Purple Queen
Around Jun 21≈ 65 days after planting
Sample dates for Pittsburgh, PA. Sign up to get exact Yard Long Bean Purple Queen dates for your own zip code.
Growing Conditions
Soil
Growing Zones
Find your zone →Thrives in zones 9-11; can be grown as warm-season annual in zones 3-8 after last frost
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Seedling
10-14 daysSprouting occurs within 7-10 days. Cotyledons emerge, followed by the first true leaves. Plants remain low and compact.
Keep soil consistently moist but not waterlogged. Provide bright light (indoors, use grow lights 14 hours daily). Maintain warmth (70-80°F). Thin to strongest seedling if direct sowing multiple seeds per spot.
Vegetative Growth
3-4 weeksVigorous vine growth with compound leaves. Tendrils develop and plant begins climbing. No flowers yet. Purple-tinged stems become visible on Purple Queen variety.
Provide sturdy trellis, stake, or support structure early. Water regularly as vines expand significantly. Fertilize every 2-3 weeks with balanced fertilizer or side-dress with compost. Ensure full sun exposure. Remove any damaged or diseased leaves.
Flowering
2-3 weeks (overlaps with fruiting)Small purple-tinged white or light purple flowers appear in clusters along the vine. Flowers are delicate and appear progressively as the vine continues growing.
Maintain consistent moisture—critical for fruit set. Reduce nitrogen slightly to favor flowering over excessive foliage. Continue supporting vine growth. Do not disturb flowering areas. Monitor for pests which are attracted to flowering plants.
Pod Development & Fruiting
6-8 weeks (continuous until frost)Dark purple pods elongate rapidly, reaching 12-16 inches in length. Pods are smooth and slender with tender texture. Multiple pods develop in succession along the vine. Pods will turn green when cooked.
Harvest pods every 2-3 days when 10-14 inches long for peak tenderness and to encourage more flowering. Maintain consistent watering—irregular watering causes pod drop and reduced yields. Support heavy-laden vines. Continue fertilizing every 3 weeks.
Maturity & Harvest
Until frost (8-12 weeks in ideal conditions)Plant produces abundantly with consistent daily harvests possible. Mature pods should be tender and snap easily. As season progresses, pods may become slightly tougher if left too long on vine.
Regular harvesting extends season and increases total yield significantly. Harvest in early morning when pods are fully turgid. Leave some pods to mature and dry for seed saving if desired (requires 4-5 additional weeks). Remove any yellowing foliage. Continue watering until first frost.
Companion Planting
Plan your garden →Plant with:
Avoid planting near:
Common Pests
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Spray with neem oil or insecticidal soap every 7 days. Increase humidity by misting. Remove heavily infested leaves. Encourage natural predators like ladybugs.
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Hand-pick beetles and yellow egg clusters daily. Use row covers on young plants. Spray with spinosad or neem oil if infestation is severe. Remove and destroy affected foliage.
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Use yellow sticky traps to monitor and control. Spray with insecticidal soap or neem oil. Encourage parasitic wasps. Remove heavily infested leaves.
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Spray with water to dislodge. Use insecticidal soap or neem oil. Release ladybugs for biological control. Avoid excessive nitrogen fertilizer which promotes aphid susceptibility.
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Ensure good air circulation and avoid overhead watering. Spray with sulfur dust or potassium bicarbonate fungicide every 7-10 days. Remove affected leaves. Space plants properly.
Uses
Stir-Fries & Asian Cuisine
CulinaryPurple Queen pods are ideal for stir-fries, curries, and Asian noodle dishes. The tender texture and subtle flavor work beautifully with garlic, ginger, soy sauce, and sesame oil. The purple color fades to green when cooked but adds visual appeal to fresh preparations. [source]
Fresh & Steamed Preparation
CulinaryPods can be steamed or boiled for 5-7 minutes as a simple side dish, similar to green beans. They are lower in calories and higher in protein than common green beans, making them nutritious for any meal. [source]
Nutritional & Protein Content
MedicinalYard long beans are excellent sources of plant-based protein, dietary fiber, and essential minerals including iron, magnesium, and potassium. They contain beneficial polyphenols and antioxidants that support overall health. [source]
Seed Preservation & Heirloom Growing
HouseholdPurple Queen pods can be allowed to mature and dry on the vine for seed saving. The resulting seeds are viable and can be replanted the following season, making this an economical and sustainable gardening practice. [source]
Pollinator Support & Garden Biodiversity
WildlifeThe delicate flowers attract bees and other pollinators, supporting garden ecosystem health and biodiversity. Growing yard long beans encourages natural pollinator populations which benefit the entire garden. [source]
This is not medical advice. LizPlants is not a medical resource. Always consult a qualified healthcare professional before using plants medicinally.
Harvest Tips
Begin harvesting when pods reach 10-14 inches long and are still tender; this is typically 55-65 days after planting. Harvest every 2-3 days by gently snapping or cutting pods at the stem. Early morning harvest yields the crispest, most tender pods. Regular harvesting encourages continuous flowering and production—leaving mature pods on the vine will reduce overall yield. Pods can be stored in the refrigerator for up to 5-7 days in a plastic bag. For seed saving, allow 3-4 pods to fully mature on the vine (approximately 4-5 additional weeks), turning brown and papery. Pod productivity continues until the first frost.
Fun Facts
- 🌱 Yard long beans are called 'asparagus beans' in some regions because of their delicate, slightly asparagus-like flavor and tender texture when young.
- 🌱 Despite the name, these beans typically reach 12-16 inches rather than a full yard (36 inches), though some exceptional varieties can approach yard-length under ideal conditions.
- 🌱 Purple Queen and other dark-podded varieties contain anthocyanins, powerful antioxidant compounds also found in blueberries, which give the pods their distinctive purple color.
Gardening Terms
New to gardening? Learn about terms used in this guide:
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