Onion Spacing Guide
Spacing affects bulb size - here's how to get the onions you want
Quick Reference
Spacing = Size
With onions, spacing directly affects bulb size. Want big onions? Space them farther apart. Happy with medium onions? Plant closer and get more per square foot. It's a trade-off!
Spacing by Onion Type
Bulbing Onions
Yellow, red, and white storage onions.
Green Onions (Scallions)
Harvested young for the green tops and small white bulb.
Shallots
Plant one set, harvest a cluster of shallots.
Intensive Onion Planting
Onions are perfect for intensive planting - shallow roots don't compete much.
- Staggered rows - Offset plants for better space use
- Wide beds - Plant 4-6 rows per 4-foot bed
- Harvest early - Pull every other onion as green onions, let rest size up
- Interplant - Grow lettuce between onion rows (harvest before onions need space)
Container Growing
Bulbing Onions
- • Container depth: 8+ inches
- • Space 4-6 inches apart
- • 5-gallon pot: 4-5 onions
- • Use wide, shallow containers
Green Onions
- • Container depth: 4+ inches
- • Space 1-2 inches apart
- • Perfect for window boxes
- • Regrow from kitchen scraps!
Frequently Asked Questions
How far apart should onions be planted?
For full-sized bulbing onions, space 4-6 inches apart in rows 12-18 inches apart. Closer spacing (3-4 inches) produces smaller onions. Green onions can be planted 1-2 inches apart.
How many onions per square foot?
In square foot gardening: bulbing onions 9 per square foot (3x3 grid), green onions 16 per square foot. Closer spacing yields more but smaller bulbs.
How deep should onions be planted?
Plant onion sets 1 inch deep with the pointed end up. Transplants should be planted at the same depth they grew in the pot. Green onions barely need covering.
Does onion spacing affect bulb size?
Yes! Closer spacing = smaller bulbs. For large onions, space 6 inches apart. For medium onions, 4 inches. Plant closer if you prefer smaller onions or will harvest some early.