How to Grow Red Candy Onion
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Red Candy Onion
Allium cepa var. aggregatum
vegetableRed Candy is a sweet, storage-type onion with deep red-burgundy skin and crisp, mild-flavored flesh. It's prized for its natural sweetness, tenderness, and excellent keeping quality. This Italian heirloom variety is perfect for fresh eating, grilling, and long-term storage.
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Example Red Candy Onion timeline · Pittsburgh, PA (Zone 6b)
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Plant Red Candy Onion
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 Red Candy Onion
Around Jul 26≈ 100 days after planting
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Growing Conditions
Soil
Growing Zones
Find your zone →Thrives in zones 4-9, can be grown in zone 3 with season extension
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Seedling/Transplant Establishment
2-3 weeksThin green shoots emerge and develop 2-3 true leaves; shallow root system establishing.
Keep soil consistently moist but not waterlogged. Begin fertilizing with diluted nitrogen-rich feed every 2 weeks. Protect from wind damage.
Vegetative Growth
4-6 weeksMultiple green shoots growing upright; foliage develops into hollow tubes; root system deepens.
Maintain consistent moisture and feed with balanced or nitrogen-rich fertilizer every 3 weeks. Mulch to retain moisture and suppress weeds. Monitor for pests.
Bulb Initiation & Swelling
4-6 weeksBases of foliage thicken and swell at soil surface; red coloring begins to develop on outer layers.
Switch to lower-nitrogen, higher-potassium fertilizer (5-10-10) to promote bulb development. Maintain even moisture. Gradually reduce watering as bulbs mature.
Maturation & Curing
2-3 weeksFoliage yellows and falls over; outer skin develops deep burgundy color and papery texture; bulb hardens.
Stop watering once tops fall over. Allow 1-2 weeks for curing in field (in dry weather) or pull and cure indoors. Handle carefully to avoid bruising.
Harvest & Storage
Harvest at maturity; stores 4-6 monthsBulbs fully mature with hard papery skin; necks closed and dry; ready for storage.
Harvest when 75-80% of tops have fallen over. Cure in cool, airy location (60-70°F, low humidity) for 2-3 weeks. Store in mesh bags in cool (40-50°F), dry conditions.
Common Pests
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Use row covers over young plants; practice crop rotation; apply beneficial nematodes or spinosad if damage appears
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Spray with insecticidal soap or neem oil; remove debris; maintain adequate spacing for air circulation
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Ensure good air circulation; avoid overhead watering; apply sulfur or copper fungicide if needed; remove infected foliage
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Practice 3-year crop rotation; plant disease-resistant sets; ensure excellent drainage; avoid overwatering at maturity
Uses
Fresh eating and mild preparations
CulinaryRed Candy's natural sweetness and tender texture make it exceptional for fresh use in salads, salsas, and raw preparations. Its mild flavor is ideal for those who find typical onions too sharp. [source]
Grilling and caramelization
CulinaryThe high sugar content caramelizes beautifully when grilled, roasted, or slow-cooked, developing rich, complex sweetness. Perfect for burgers, kebabs, and side dishes. [source]
Pickling and preservation
CulinaryRed Candy's firm texture and attractive color make it ideal for pickling, creating crispy, tangy condiments that retain their vibrant hue. [source]
Long-term storage
HouseholdBred for excellent storage quality, Red Candy bulbs keep 4-6 months in cool, dry conditions, providing fresh onions well into winter without refrigeration. [source]
Quercetin and antioxidant benefits
MedicinalLike all onions, red varieties are rich in quercetin, a flavonoid with anti-inflammatory and antioxidant properties commonly studied for health benefits. [source]
This is not medical advice. LizPlants is not a medical resource. Always consult a qualified healthcare professional before using plants medicinally.
Harvest Tips
Harvest when 75-80% of tops have fallen over and begun to dry (usually late July-August in northern zones). Gently lift bulbs with a fork, shake off soil, and cure in a warm (60-70°F), well-ventilated, dry location for 2-3 weeks. Store in mesh bags or braided strands in a cool (40-50°F), dry place for 4-6 months of storage.
Fun Facts
- 🌱 Red Candy is an Italian heirloom variety that has been cultivated for centuries in the Mediterranean region, particularly prized in Piedmont and Tuscany.
- 🌱 The red/purple coloring comes from anthocyanin pigments, the same compounds that make blueberries and red cabbage nutritious; these pigments increase in intensity with sunlight exposure.
- 🌱 Unlike many storage onions, Red Candy is naturally sweet due to its high sugar content (up to 12% in some conditions), making it one of the few onion varieties that tastes pleasant when eaten raw.
Gardening Terms
New to gardening? Learn about terms used in this guide:
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