How to Grow Torpedo Red

Torpedo Red

Allium cepa var. cepa

vegetable

Torpedo Red is a long-day, storage onion variety known for its distinctive elongated, torpedo-shaped bulbs with deep reddish-purple skin and red-tinged white interior flesh. This Italian heirloom cultivar is prized for its mild, sweet flavor and excellent keeping qualities, making it ideal for fresh eating and long-term storage.

When should you plant Torpedo Red in your zone?

Get a personalized planting timeline — when to start seeds, transplant, and harvest — based on your USDA zone and local frost dates. Free to start.

Get my Torpedo Red timeline →

Example Torpedo Red timeline · Pittsburgh, PA (Zone 6b)

  1. Plant Torpedo Red

    Around Apr 17

    Near Pittsburgh's average last spring frost.

  2. Tend & protect

    Late spring–summer

    Watering, feeding, and pest-watch reminders.

  3. Harvest Torpedo Red

    Around Jul 26

    ≈ 100 days after planting

Sample dates for Pittsburgh, PA. Sign up to get exact Torpedo Red dates for your own zip code.

Growing Conditions

☀️
Sun: Full sun, 6-8 hours daily (minimum); 8+ hours preferred for optimal bulb development
💧
Water: Consistent moisture (1-1.5 inches per week); keep soil evenly moist but not waterlogged during active growth; reduce watering as foliage yellows to encourage bulb storage compounds and curing
📏
Spacing: 4-6 inches between plants; 12-18 inches between rows inches
📅
Days to maturity: 100-120 days from transplant; 150-160 days from seed
🌱
Planting depth: Sets/seeds: 1 inch deep; transplants: plant at soil line, just covering the base

Soil

Type: Well-draining, fertile loamy soil rich in organic matter
pH: 6.0-7.0
Amendments:
Aged compost Balanced NPK fertilizer Phosphorus-rich amendments Avoid fresh manure (can cause splitting and disease)

Growing Zones

Find your zone →

Zones 4-8; thrives in cooler to moderate climates with adequate day length for bulb formation

3a 3b 4a 4b 5a 5b 6a 6b 7a 7b 8a 8b 9a

Sign up free to see if Torpedo Red grows in your zone — and get a personalized planting timeline.

Get my Torpedo Red timeline →

Growth Stages

1

Seedling

2-3 weeks

Thin green shoots emerge from soil; true leaves develop a waxy coating; plants are still establishing shallow root systems

Keep soil consistently moist; provide full sun; thin seedlings to proper spacing once 2-3 inches tall; avoid damaging roots when thinning

2

Vegetative Growth

6-8 weeks

Multiple green leaves develop in upright bundle; plants produce 4-8 leaves per bulb; foliage reaches 12-18 inches tall; underground bulb begins to enlarge

Maintain consistent watering (1-1.5 inches weekly); apply balanced fertilizer every 3-4 weeks; mulch lightly to retain moisture; monitor for pests; avoid excessive nitrogen which delays bulb formation

3

Bulbing

4-6 weeks

Foliage begins to yellow and soften; bulbs swell beneath soil surface; characteristic torpedo shape becomes visible if soil is gently brushed away; outer papery skin develops distinctive deep red-purple color

Gradually reduce watering as foliage yellows; allow soil to dry slightly; stop fertilizing; do not break over foliage early (this stresses bulbs); maintain weed control to avoid competition

4

Maturity & Harvest

2-3 weeks

Foliage falls over and dries completely; neck area tightens and hardens; papery skin becomes papery and protective; bulbs reach full torpedo shape with 2-3 inch length

Stop all watering once tops fall; harvest when 50-75% of foliage is brown and dried; cure bulbs in warm, well-ventilated area (70-80°F) for 2-3 weeks before storage

Companion Planting

Plan your garden →

Plant with:

Avoid planting near:

Beans Peas Asparagus Sage Other alliums (garlic, leek, shallot)

Common Pests

  • Use row covers over young plants; practice crop rotation; remove affected plants; apply neem oil or spinosad if infestation occurs; avoid planting near decomposing onions

  • Spray with strong water stream; use insecticidal soap or neem oil; remove infested foliage; maintain adequate spacing for air circulation

  • Increase humidity through irrigation; use miticide if severe; remove heavily infested leaves; spray with neem oil

  • Ensure good air circulation and avoid overhead watering; apply copper fungicide if spotted early; remove infected leaves; use resistant varieties if available

  • Practice crop rotation (3-4 year minimum); use disease-free sets; ensure well-draining soil; remove infected bulbs immediately; do not compost infected material

Uses

🍳

Fresh Eating & Mild Flavor

Culinary

Torpedo Red onions are notably mild and sweet with minimal pungency when raw, making them ideal for salads, sandwiches, and fresh salsas. Their tender texture and refined flavor also excel in light sautéing and grilling. [source]

🍳

Long-Term Storage & Cooking

Culinary

Excellent storage capabilities (4-6 months) and dense flesh make Torpedo Red ideal for year-round cooking in soups, stews, caramelized onion dishes, and roasting. The deep color adds visual appeal to cooked dishes. [source]

💊

Quercetin & Antioxidants

Medicinal

Red onions are rich in quercetin and anthocyanin antioxidants, compounds traditionally associated with anti-inflammatory and cardiovascular health benefits in herbal medicine. [source]

🏠

Natural Dye

Household

The deep red-purple papery skin has been used historically to produce reddish-brown dyes for textiles and can also be extracted for food coloring purposes. [source]

🦋

Pollinator Support

Wildlife

If left unharvested, Torpedo Red flowers attract bees and other pollinators, making it useful as an ornamental in native plant gardens and support systems. [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 50-75% of foliage has fallen over and turned brown-dry (typically late summer to early fall, 100-120 days after transplanting). Gently pull or dig bulbs, being careful not to bruise the papery skin. Cure in a warm (70-80°F), well-ventilated, shaded location for 2-3 weeks until necks are completely dry and papery. Trim dried foliage to 1 inch above bulb and store in cool (50-60°F), dry, dark conditions with good air circulation (hanging in mesh bags or onion braids is ideal). Properly cured Torpedo Red onions store 4-6 months or longer.

Fun Facts

  • 🌱 Torpedo Red is an Italian heirloom cultivar, named for its distinctive elongated torpedo or spindle shape that sets it apart from typical round onion varieties.
  • 🌱 The red pigmentation in Torpedo Red onions comes from anthocyanin compounds, the same class of antioxidants found in blueberries and red wine.
  • 🌱 Unlike many long-day onions, Torpedo Red can be braided or plaited while still fresh-cured for traditional 'onion ropes' or 'trenzas,' a storage method popular in Mediterranean countries.

Gardening Terms

New to gardening? Learn about terms used in this guide:

Join 30,000 gardeners planning their gardens with LizPlants.

Get your personalized Torpedo Red planting timeline

Tell us your zip code and we'll calculate exactly when to start Torpedo Red seeds, transplant seedlings, and harvest — based on your USDA zone and local frost dates. Includes calendar reminders and printable task lists. Free to start.

Get my Torpedo Red timeline →