How to Grow William Rex Potato
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William Rex Potato
Solanum tuberosum 'William Rex'
vegetableWilliam Rex is a high-yielding, mid-season potato variety with red skin and white flesh, known for excellent disease resistance and reliable production. It was developed in the United States and is popular for both home and commercial growers. The variety produces medium to large tubers suitable for boiling, mashing, and general culinary use.
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Example William Rex Potato timeline · Pittsburgh, PA (Zone 6b)
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Plant William Rex 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 William Rex Potato
Around Jul 16≈ 90 days after planting
Sample dates for Pittsburgh, PA. Sign up to get exact William Rex Potato dates for your own zip code.
Growing Conditions
Soil
Growing Zones
Find your zone →Thrives in zones 3-8; tolerates cooler climates well
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Seed Piece Sprouting
1-2 weeksSeed potato pieces develop sprouts or 'eyes' 1-2 weeks after planting in cool soil. Root development begins underground.
Ensure soil temperature is 45-60°F. Keep soil consistently moist but not waterlogged. Protect from frost.
Emergence & Early Growth
2-3 weeksShoots emerge through soil surface; plant develops first true leaves. Stolons form underground where tubers will develop.
Hill soil around emerging plants when they reach 6 inches tall. Begin first hilling. Monitor for early blight.
Vegetative Growth & Hilling
3-4 weeksPlant develops robust leafy foliage. Multiple stems grow from base. Underground stolons actively form and tubers begin to enlarge.
Hill plants 2-3 times total, adding 4 inches of soil around base each time. Apply consistent watering. Apply balanced fertilizer mid-season.
Flowering & Tuber Bulking
3-4 weeksWhite, red, or purple flowers appear. Plant reaches full size. Maximum tuber enlargement occurs during this stage.
Continue watering 1-2 inches per week. Begin watching for late blight, especially in humid conditions. Do not harvest yet.
Maturity & Harvest Ready
2-3 weeksFoliage yellows and begins to die back. Tuber skin sets and hardens. Stolons separate from mother plant.
Stop watering 2 weeks before harvest to allow skin to set. Wait until foliage is completely dead before harvesting to maximize yield and skin set.
Companion Planting
Plan your garden →Plant with:
Avoid planting near:
Common Pests
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Hand-pick eggs and larvae; use row covers on young plants; apply spinosad or neem oil; encourage beneficial insects
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Spray with water to dislodge; use insecticidal soap; introduce ladybugs; apply neem oil
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Hill plants well to prevent exposed tubers; use row covers; apply Bt; harvest and store properly
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Rotate crops; till soil in fall/spring; use beneficial nematodes; handpick if severe
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Plant disease-resistant varieties; improve air circulation; remove infected leaves; apply copper fungicide; avoid overhead watering
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Remove lower leaves as plant grows; improve drainage and air circulation; apply fungicide if needed; rotate crops
Uses
General Kitchen Cooking
CulinaryWilliam Rex potatoes are excellent all-purpose potatoes with good flavor and firm texture. They boil and mash well without breaking apart, making them ideal for home cooking, boiling, steaming, and mashing. [source]
Salads & Cold Dishes
CulinaryThe firm, waxy texture holds its shape well during cooking, making William Rex particularly good for potato salads, cold salads, and prepared dishes. [source]
Storage & Winter Use
CulinaryWilliam Rex potatoes store very well for 3-6 months in proper conditions, providing fresh homegrown nutrition throughout fall and winter. [source]
Home Food Security
HouseholdThis high-yielding, disease-resistant variety is ideal for home gardeners seeking food independence and reliable harvests year after year. [source]
Garden Biodiversity
WildlifePotato plants provide habitat for beneficial insects, and growing diverse potato varieties supports agricultural biodiversity and ecosystem health. [source]
Harvest Tips
William Rex typically matures in 90-110 days. Harvest when foliage has completely yellowed and died back for best skin set and storage. Dig carefully with a fork to avoid bruising tubers. Cure harvested potatoes in cool (50-60°F), humid (85-90% relative humidity), dark location for 1-2 weeks before storage to allow skin to fully harden. Store in cool (45-50°F), dark, humid conditions with good air circulation. Early or new potatoes can be harvested 2-3 weeks earlier if desired, but yield will be lower.
Fun Facts
- 🌱 William Rex potatoes were developed to have excellent disease resistance, particularly to common potato diseases, making them a favorite among home gardeners who want reliable harvests with minimal fungicide applications.
- 🌱 Potatoes are the world's fourth most important staple crop after rice, wheat, and corn, and varieties like William Rex were bred to maximize both yield and nutritional value for global food security.
- 🌱 The red skin of William Rex contains more anthocyanins and other antioxidants than white potato varieties, contributing to its nutritional profile and slightly earthy flavor.
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