How to Grow Black Jewel Potato
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Black Jewel Potato
Solanum tuberosum 'Black Jewel'
vegetableBlack Jewel is a mid-season potato variety prized for its striking deep purple-black skin and flesh with a waxy texture and excellent flavor. It produces oblong tubers with high antioxidant content and maintains color when cooked. This variety is popular among specialty growers and chefs for culinary appeal and nutritional value.
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Example Black Jewel Potato timeline · Pittsburgh, PA (Zone 6b)
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Plant Black Jewel Potato
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 Black Jewel Potato
Around Jul 1≈ 75 days after planting
Sample dates for Pittsburgh, PA. Sign up to get exact Black Jewel Potato dates for your own zip code.
Growing Conditions
Soil
Growing Zones
Find your zone →Thrives in zones 3-8; prefers cool-season growing conditions
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Seed Piece Sprouting
2-3 weeksSeed potatoes develop sprouts and root systems underground; soil begins to crack as shoots emerge.
Ensure soil is 45°F or warmer before planting. Keep soil consistently moist. Provide well-draining soil to prevent rot. Plant certified seed pieces.
Vegetative Growth
3-4 weeksStems and foliage emerge above ground and rapidly develop compound leaves. Plants establish bushy growth with multiple shoots.
Begin hilling soil around stems when plants are 6-8 inches tall to prevent sunlight exposure of tubers. Hill every 2-3 weeks. Monitor for pests. Maintain consistent water.
Flowering
2-3 weeksPlants produce clusters of small flowers ranging from white to light purple. Flowering indicates tuber formation underground.
Continue hilling to ensure developing tubers stay covered. Maintain regular watering schedule. Fertilize with balanced NPK or potassium-rich formula to support tuber development.
Tuber Bulking
3-4 weeksUnderground, tubers expand rapidly and develop full color intensity, including the characteristic deep purple-black skin and flesh.
Keep soil moist but avoid waterlogging; reduce frequency if rainfall is adequate. Stop excessive nitrogen fertilizing to prevent lush foliage at expense of tubers. Monitor soil temperature.
Maturity & Harvest
At harvest readinessFoliage begins to yellow and die back naturally; skin sets and becomes firm. Tubers reach full size with developed, thick skin for storage.
Stop watering 2 weeks before harvest to allow skins to set fully. Cut down dead foliage before digging. Harvest carefully to avoid bruising and damage to tubers.
Companion Planting
Plan your garden →Plant with:
Avoid planting near:
Common Pests
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Hand-pick and destroy. Use row covers on young plants. Apply neem oil, spinosad, or pyrethrin sprays. Rotate crops yearly.
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Use reflective mulches. Apply insecticidal soap or neem oil. Maintain resistant varieties when possible. Use yellow sticky traps.
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Avoid planting in recently sod-turned soil. Crop rotation. Beneficial nematodes in soil. Check seed pieces for damage before planting.
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Use resistant varieties when available. Ensure excellent air circulation and drainage. Remove infected foliage immediately. Apply copper fungicide or sulfur preventively in wet conditions.
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Maintain soil pH below 6.8. Improve drainage. Use disease-free seed stock. Avoid fresh manure; use aged compost instead.
Uses
Colorful Potato Dishes
CulinaryBlack Jewel potatoes retain their dramatic purple-black color when cooked, making them visually striking in mashed potatoes, roasts, and salads. Their waxy texture holds shape well in boiling and cooking methods, making them ideal for potato salad and side dishes. [source]
Antioxidant-Rich Food
MedicinalBlack Jewel potatoes are exceptionally high in anthocyanins and other polyphenolic compounds that support cardiovascular health and reduce inflammation. The deep purple color indicates elevated antioxidant content compared to standard white or russet potatoes. [source]
Specialty Cooking & Presentation
CulinaryChefs favor Black Jewel for upscale plating and gourmet presentations where the striking color enhances dish aesthetics. The natural pigmentation adds visual interest to traditional potato preparations without artificial dyes. [source]
Seed Stock Propagation
HouseholdBlack Jewel can be saved and replanted by preserving healthy seed potatoes from your harvest. Store disease-free tubers in optimal conditions and plant them the following season for self-sufficiency. [source]
Garden Biodiversity
WildlifeGrowing Black Jewel potatoes as a garden crop supports beneficial insects that pollinate flowers and soil organisms that improve soil health. The flowering stage provides early-season nectar sources. [source]
This is not medical advice. LizPlants is not a medical resource. Always consult a qualified healthcare professional before using plants medicinally.
Harvest Tips
Black Jewel reaches maturity 75-90 days after planting. Harvest after foliage dies back naturally or 2-3 weeks after last hilling. Carefully dig tubers with a garden fork, working outward from the stem to avoid bruising. Store in cool (50-60°F), dark, humid conditions for up to 4-5 months. Cure in a cool, dark location for 1-2 weeks before storage to toughen skins.
Fun Facts
- 🌱 Black Jewel potatoes were developed through traditional potato breeding at the University of Maine and were released in 1983, becoming a cornerstone variety for specialty potato growers.
- 🌱 The deep purple-black pigmentation comes from anthocyanins, the same powerful antioxidants found in blueberries and blackberries, making them one of the most nutrient-dense potato varieties.
- 🌱 Unlike many ornamental purple potatoes that can have less flavor, Black Jewel maintains excellent taste and texture, striking a balance between visual appeal and culinary merit.
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