How to Grow Southport Red Globe Onion
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Southport Red Globe Onion
Allium cepa 'Southport Red Globe'
vegetableSouthport Red Globe is a classic long-day onion variety prized for its deep red color, excellent storage capacity, and uniform globe-shaped bulbs. This heirloom variety produces medium to large bulbs with thin, papery skin and firm, flavorful flesh ideal for cooking and storage. It was developed in Connecticut in the 1880s and remains a favorite among gardeners for its reliability and disease resistance.
When should you plant Southport Red Globe Onion in your zone?
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Example Southport Red Globe Onion timeline · Pittsburgh, PA (Zone 6b)
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Plant Southport Red Globe 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 Southport Red Globe Onion
Around Jul 26≈ 100 days after planting
Sample dates for Pittsburgh, PA. Sign up to get exact Southport Red Globe Onion dates for your own zip code.
Growing Conditions
Soil
Growing Zones
Find your zone →Zones 3-7 are ideal; thrives in northern climates where long daylight hours trigger bulb formation
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Seedling (from seed)
3-4 weeksThin grass-like leaves emerge; develop first true leaf and root system
Start indoors 6-8 weeks before last frost; keep soil consistently moist; provide bright light to prevent legginess; thin seedlings to prevent crowding
Transplant/Establishment
2-3 weeksYoung plants are hardened off and transplanted to garden; establish root system and begin leaf growth
Plant at true soil line; water gently after transplanting; provide consistent moisture; apply mulch to retain soil moisture; protect from wind damage
Vegetative Growth (Bulbing Phase)
6-10 weeksFoliage grows tall (12-18 inches); bulbs begin to swell underground as days lengthen; white fleshy scales form beneath soil
Maintain consistent watering (1-1.5 inches weekly); provide balanced nitrogen fertilizer mid-season; keep bed weed-free; monitor for pests; mulch around base (not touching stems)
Bulb Maturation
3-4 weeksFoliage begins to yellow and fall over; bulbs reach full size and outer scales papery; bulb skin darkens to deep red
Reduce watering significantly; do not break over foliage (it's not necessary and can damage bulbs); stop fertilizing; improve air circulation around plants; watch for disease in damp conditions
Harvest & Curing
2-4 weeks curingTops die back completely and dry; bulbs pulled and laid on soil to cure; outer skins harden and papery
Harvest when 50-75% of foliage has fallen over; cure in warm, dry, well-ventilated location for 2-4 weeks; do not wash until after curing; trim dried tops to 1 inch after curing is complete
Companion Planting
Plan your garden →Plant with:
Avoid planting near:
Common Pests
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Use row covers until plants are established; remove infested plants; practice crop rotation; apply spinosad if necessary
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Spray with water to dislodge; use insecticidal soap or neem oil; reflective mulches deter; remove heavily infested plants
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Use floating row covers; remove affected bulbs immediately; allow 3-4 year crop rotation; diatomaceous earth around base
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Practice crop rotation (4-5 years); use resistant varieties when possible; improve drainage; avoid overwatering; remove infected plants
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Ensure excellent drainage; cure bulbs thoroughly; store in cool (32-45°F), dry (60-70% humidity) conditions; remove affected bulbs immediately
Uses
Caramelizing and cooking
CulinarySouthport Red Globe onions are excellent for caramelizing due to their sweetness and firm texture. They hold their shape well when cooked and develop rich, complex flavors ideal for soups, stews, French onion soup, and roasted vegetable dishes. [source]
Fresh use and salads
CulinaryThe mild, slightly sweet flavor makes these onions pleasant raw in salads, salsas, and relishes when thinly sliced. The deep red color adds visual appeal to fresh dishes. [source]
Long-term storage
HouseholdSouthport Red Globe is famous for exceptional storage life (4-6+ months) when properly cured and kept in cool, dry conditions. This makes it ideal for home gardeners who want fresh onions throughout winter. [source]
Quercetin and antioxidants
MedicinalRed onions are rich in quercetin, a flavonoid with anti-inflammatory and antioxidant properties. Red-skinned varieties contain significantly more flavonoids than white varieties. [source]
Natural dye production
CraftThe deep red papery skins can be used to create natural dyes for textiles and paper crafts, producing warm rust and burgundy tones. [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 in late summer when 50-75% of foliage has naturally fallen over and dried; gently loosen soil and pull bulbs by hand; leave roots and dried tops intact for curing. Cure in warm (70-80°F), dry, well-ventilated space for 2-4 weeks before storing. Properly cured bulbs store 4-6 months (or longer) in cool, dry conditions.
Fun Facts
- 🌱 Southport Red Globe was developed in Southport, Connecticut in the 1880s and is named after that town; it's considered a true American heirloom variety that revolutionized onion growing in the Northeast.
- 🌱 This variety is a 'long-day' onion, requiring 14-16 hours of daylight to trigger bulbing, making it perfectly suited to northern regions and explaining why it fails to form proper bulbs in southern climates.
- 🌱 Properly cured Southport Red Globe onions can store for 6+ months without refrigeration, and some gardeners report keeping them viable for 8+ months under ideal conditions (32-45°F, 60-70% humidity), making it an excellent choice for food security and self-sufficiency.
Gardening Terms
New to gardening? Learn about terms used in this guide:
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