How to Grow Bombay Red Onion
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Bombay Red Onion
Allium cepa
vegetableBombay Red is a deep red, globe-shaped onion variety prized for its rich color, mild flavor, and excellent storage capability. Originally developed in India, it has become popular worldwide for both fresh market and long-term storage applications. The variety produces large, firm bulbs with papery red skin and reddish layers throughout.
When should you plant Bombay Red Onion in your zone?
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Example Bombay Red Onion timeline · Pittsburgh, PA (Zone 6b)
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Plant Bombay Red 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 Bombay Red Onion
Around Jul 26≈ 100 days after planting
Sample dates for Pittsburgh, PA. Sign up to get exact Bombay Red Onion dates for your own zip code.
Growing Conditions
Soil
Growing Zones
Find your zone →Thrives in zones 3-9; best in zones 5-8
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Get my Bombay Red Onion timeline →Growth Stages
Seedling (from seed)
3-4 weeksThin, grass-like shoots emerge from soil; tiny white roots develop. Very delicate at this stage.
Keep soil consistently moist but not waterlogged. Provide bright light. Thin seedlings to prevent overcrowding. If starting indoors, maintain 70-75°F for germination.
Establishment
4-6 weeksYoung plants develop 2-3 true leaves and establish stronger root systems. Transplants are ready when 4-6 inches tall with pencil-thick stems.
Harden off transplants gradually if grown indoors. Apply light nitrogen fertilizer every 2 weeks. Keep consistent soil moisture. Mulch lightly to retain moisture.
Vegetative/Bulb Initiation
6-8 weeksFoliage grows tall and green; underground bulb formation begins. Plants develop 4-6 visible leaves; subtle bulge appears at soil surface.
Maintain consistent watering and weekly nitrogen feeding. Ensure 10+ hours of daylight—day length triggers bulb formation. Keep soil weed-free. Remove any flower scapes if they appear.
Bulb Development & Maturation
4-6 weeksVisible bulbs swell rapidly underground; outer papery red skin develops. Foliage remains green but begins to thicken near the base.
Gradually reduce watering as bulbs mature. Stop fertilizing when bulbs reach tennis-ball size. Do not hill soil over bulbs—they need light exposure for color development. Ensure good air circulation to prevent rot.
Harvest & Curing
2-3 weeks curingTops yellow and fall over naturally; outer skins papery and loose. Bulbs are fully mature and ready for harvest.
Stop watering 2 weeks before harvest. Once 50-75% of tops have fallen over, gently loosen soil and pull bulbs. Cure in warm, dry, well-ventilated space (65-75°F) for 2-3 weeks before storing.
Companion Planting
Plan your garden →Plant with:
Avoid planting near:
Common Pests
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Use row covers during early growth. Apply diatomaceous earth. Rotate crops yearly. Remove and destroy affected plants immediately.
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Spray with neem oil or insecticidal soap. Maintain consistent irrigation. Remove weeds that harbor thrips.
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Ensure well-draining soil. Avoid overwatering. Use disease-resistant sets. Do not plant in infested soil for 4+ years.
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Improve air circulation. Avoid overhead watering. Remove infected leaves. Apply sulfur or copper fungicide if needed.
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Ensure good air circulation and avoid overhead irrigation. Apply copper fungicide. Plant in well-draining soil.
Uses
Fresh salads and slicing
CulinaryBombay Red onions have a mild, sweet flavor when raw, making them ideal for fresh salads, sandwiches, and crudités. They are often preferred over yellow onions for applications where a less harsh bite is desired. [source]
Cooking and caramelizing
CulinaryTheir firm texture holds up well to roasting, grilling, and caramelizing. The natural sugars develop rich, complex flavors when slow-cooked. [source]
Pickling and preservation
CulinaryThe dense structure and mild flavor make Bombay Reds excellent for pickling, chutneys, and relishes. They retain their vibrant color during preservation. [source]
Quercetin and antioxidants
MedicinalRed onions are particularly rich in quercetin and anthocyanins, which have anti-inflammatory and antioxidant properties. Traditional medicine uses have included immune support and cardiovascular health. [source]
Long-term storage
HouseholdBombay Red's excellent keeping quality (5-8 months in proper conditions) makes it ideal for home gardeners seeking reliable winter onion supplies without continuous planting. [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 yellowed and fallen over naturally, typically 100-120 days after transplanting. Gently loosen soil and pull bulbs by hand. Cure in a warm (65-75°F), dry, well-ventilated location for 2-3 weeks until outer skins are completely papery. Once cured, trim tops to 1-2 inches and store in cool (35-40°F), dry conditions with good air circulation. Properly stored Bombay Red onions keep 5-8 months.
Fun Facts
- 🌱 Despite its name, Bombay Red was actually developed in the United States, not India, though it draws inspiration from Indian heirloom onion varieties.
- 🌱 Red onions owe their color to anthocyanins—the same antioxidant pigments found in blueberries and red wine—which are enhanced in acidic soils.
- 🌱 A single mature Bombay Red onion can weigh 4-8 ounces and contains over 100 layers of papery leaves, each serving as a protective barrier for storage.
Gardening Terms
New to gardening? Learn about terms used in this guide:
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