Contents
- 1 How to Grow Onions Indoors (Greens & Bulbs in Pots)
- 1.1 Why Grow Onions Indoors?
- 1.2 Best Conditions for Growing Onions Indoors
- 1.3 Planting Onions Indoors
- 1.4 Caring for Indoor Onions
- 1.5 Harvesting Onions Indoors
- 1.6 Best Onion Varieties for Indoor Growing
- 1.7 Common Problems When Growing Onions Indoors
- 1.8 FAQs About Growing Onions Indoors
- 1.9 Related Articles
- 1.10 Final Thoughts on Growing Onions Indoors
How to Grow Onions Indoors (Greens & Bulbs in Pots)
Onions are one of the most versatile kitchen staples, and the good news is you don’t need a garden to grow them. With the right setup, you can grow onions indoors for both fresh green shoots (like scallions) and small bulbs. This beginner-friendly guide will walk you through everything you need to know to grow onions successfully inside pots or containers.
Why Grow Onions Indoors?
Growing onions indoors offers several advantages:
Year-round harvests: Always have fresh onion greens ready for cooking.
Space-saving: Perfect for apartments and small homes.
Beginner-friendly: Low maintenance and fast-growing.
Dual harvests: Enjoy both green tops and small bulbs.
Best Conditions for Growing Onions Indoors
To thrive indoors, onions need the right light, soil, and container setup.
Light: 10–12 hours of bright light daily. A sunny windowsill or grow light works best.
Temperature: 15–22°C (60–72°F). Avoid extreme heat.
Soil: Loose, well-draining potting mix enriched with compost.
Container: At least 6–8 inches deep for greens, and 10–12 inches for bulbs.
You can find this Deep Container for Vegetables on Amazon.
Planting Onions Indoors
There are three easy ways to start growing onions inside:
From sets: Small onion bulbs (sets) are the fastest way to grow bulbs. Plant them 1–2 inches deep, spaced 3–4 inches apart.
From seed: Sow seeds ¼ inch deep. They take longer but are cost-effective.
From scraps: Place the base of a store-bought onion in water or soil to regrow greens.
Caring for Indoor Onions
Once planted, onions require simple but consistent care:
Watering: Keep soil moist but not soggy. Overwatering can cause rot.
Fertilizer: Feed with a balanced liquid fertilizer every 2–3 weeks.
Thinning: Thin seedlings so each has enough room to grow.
Air circulation: Place near a window or fan to reduce fungal issues.
Check price for Indoor LED Grow Light on Amazon to keep onions strong in low-light homes.
Harvesting Onions Indoors
You can harvest onions in two different ways:
Green tops (scallions): Snip the greens once they reach 6–8 inches tall. They regrow quickly.
Bulbs: Harvest when the tops begin to yellow and fall over, usually 90–120 days depending on the variety.
Best Onion Varieties for Indoor Growing
Some onion types perform better in containers than others. Good choices include:
‘Evergreen Bunching’ – Fast-growing, perfect for green shoots.
‘Red Baron’ – Small, flavorful red bulbs.
‘White Lisbon’ – Classic spring onion for continuous harvests.
‘Crystal Wax’ – Mild white bulbs, ideal for pots.
Common Problems When Growing Onions Indoors
Yellowing leaves: Often caused by overwatering or lack of nutrients.
Weak bulbs: Not enough sunlight or overcrowding.
Pests (like aphids): Rare indoors but can appear — use a mild soap spray if needed.
For further growing advice, check the Royal Horticultural Society’s onion guide.
FAQs About Growing Onions Indoors
1. Can I grow onions indoors all year?
Yes — as long as you provide enough light and keep temperatures steady.
2. How long do onions take to grow indoors?
Greens can be harvested in 3–4 weeks, while bulbs take 3–4 months.
3. Do onions need deep pots to grow bulbs?
Yes, at least 10–12 inches deep for full bulb development.
Related Articles
Final Thoughts on Growing Onions Indoors
Growing onions indoors is one of the easiest ways to enjoy fresh flavors from your own home. With the right pot, soil, and light, you can harvest both onion greens and bulbs year-round. Start planting onions today, and you’ll always have this kitchen essential within arm’s reach.
