How to Grow Purple King Bean
Wikimedia Commons
Purple King Bean
Phaseolus vulgaris
vegetablePurple King is a bush bean variety prized for its distinctive deep purple pods and excellent flavor. These compact plants produce abundant yields of tender, flavorful beans that turn green when cooked. This is a popular heirloom variety known for both productivity and ornamental appeal in the garden.
When should you plant Purple King Bean in your zone?
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Example Purple King Bean timeline · Pittsburgh, PA (Zone 6b)
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Plant Purple King Bean
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 Purple King Bean
Around Jun 6≈ 50 days after planting
Sample dates for Pittsburgh, PA. Sign up to get exact Purple King Bean dates for your own zip code.
Growing Conditions
Soil
Growing Zones
Find your zone →Thrives in zones 3-9; prefers warm soil and air temperatures
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Germination & Seedling
7-14 daysSeeds sprout in 7-10 days; cotyledons emerge followed by true leaves; plants are low and compact
Ensure consistent soil moisture without waterlogging; maintain soil temperature above 60°F for optimal germination; thin seedlings if needed
Vegetative Growth
2-3 weeksBushy plants develop dense foliage with typical bean leaf structure; plants remain compact (12-18 inches tall); no flowering yet
Monitor for early pest problems; maintain consistent watering; avoid excess nitrogen which promotes foliage over pods; provide full sun exposure
Flowering
1-2 weeksSmall white or light pink flowers appear in clusters; distinctive purple-tinged foliage becomes more visible; plants reach full size
Increase watering as water demands peak; apply consistent fertilization; avoid disturbing plants; ensure adequate spacing for air circulation
Pod Development
2-3 weeksVibrant deep purple pods develop rapidly from flower sites; pods grow 5-6 inches long and remain tender; multiple flushes of pods appear
Maintain consistent moisture for tender pod development; continue regular harvesting to encourage more production; watch for spider mites and aphids
Harvest & Production
3-4 weeksPods reach full length and tender stage; deep purple color is most vibrant; plants continue producing new flowers and pods for several weeks
Pick pods every 2-3 days when young and tender (snap stage); handle plants gently to avoid breaking branches; continue regular watering and harvesting
Companion Planting
Plan your garden →Plant with:
Avoid planting near:
Common Pests
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Hand-pick beetles and orange egg clusters; use row covers on young plants; apply neem oil or spinosad if needed; encourage beneficial insects
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Spray with strong water stream to dislodge; increase humidity; use miticides or neem oil; ensure adequate watering to reduce stress
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Spray with insecticidal soap; use strong water spray; encourage ladybugs and lacewings; apply neem oil for heavy infestations
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Use row covers on seedlings; hand-pick beetles; apply kaolin clay; plant trap crops; use spinosad if necessary
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Water at soil level only; ensure good air circulation; remove infected leaves; apply sulfur spray; avoid overhead watering
Uses
Fresh snap beans
CulinaryTender purple pods are excellent steamed, sautéed, roasted, or eaten raw; they turn green when cooked but retain excellent flavor and texture. Versatile addition to stir-fries, salads, and side dishes. [source]
Dried beans for storage
CulinaryMature dry beans from Purple King can be harvested and stored for use in soups, stews, and baked bean dishes throughout the year. Provides reliable protein-rich pantry staple. [source]
Ornamental garden accent
HouseholdThe striking deep purple pods and purple-tinged foliage make Purple King an attractive edible ornamental for decorative vegetable gardens. Complements flower beds while providing food production. [source]
Immature pod texture
CulinaryYoung Purple King pods have a tender, crisp texture superior to many green snap bean varieties, making them particularly prized for fresh consumption. The purple color also provides visual interest on the plate. [source]
Pollinator support
WildlifeBean flowers attract bees and other beneficial pollinators, supporting garden ecosystem health and contributing to broader food production. The flowers are delicate and appealing to beneficial insects. [source]
Harvest Tips
Begin harvesting when pods are 5-6 inches long and tender (snap stage), before seeds enlarge; pods should snap cleanly when bent; harvest every 2-3 days to encourage continuous production; morning harvest after dew dries is best; mature pods turn dark purple and become fibrous; for dry beans, allow pods to dry on plant, then harvest when pods are brown and brittle
Fun Facts
- 🌱 Purple King beans turn green when cooked due to the breakdown of anthocyanin pigments (the purple color compound) at higher temperatures, making them visually striking raw but conventionally colored when prepared.
- 🌱 Beans are nitrogen-fixing legumes that form symbiotic relationships with soil bacteria, naturally enriching garden soil with nitrogen and reducing the need for synthetic fertilizers.
- 🌱 Purple King is an heirloom variety that has been grown for generations, with seeds saved and replanted annually by gardeners appreciating its exceptional flavor and reliable productivity.
Gardening Terms
New to gardening? Learn about terms used in this guide:
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