Onion

Botanical Name

Allium cepa var. cepa

Hardiness

Annual

Height

1 to 3 feet

Width

6 to 12 inches

Flowers

Mid summer: usually doesn't flower unless stressed or grown from sets that are too large

Fruit

Yellow, white, or red

Light

Full sun

Soil

Moist, well-drained, rich

Planting & Care

Can be direct seeded in the garden if grown for harvesting as scallions
Begin sowing when the soil temperature reaches 50°F. Plant seeds ¹/₄ deep and space ¹/₂ apart. Thin to ¹/₂ to 1 inch spacing.
Can be started from seed indoors 8 to 10 weeks before last frost date. Sow seeds ¹/₄ deep and ¹/₂ apart. Harden off and set out in the garden 2 to 4 weeks before last frost date.
Space transplants 4 inches apart for large bulbs, 2 inches for small bulbs and ¹/₂ to 1 inch if harvesting as scallions. Space rows 12 to 18 inches apart.
Transplant sets (young bulbs about ¹/₂ inch in diameter) 1 inch deep 2 to 4 weeks before last frost date. Space sets 4 inches apart for large bulbs, 2 inches for small bulbs and ¹/₂ to 1 inch if harvesting as scallions.
To develop long white stems on scallions, hill the soil around the onions when they grow to 4 inches tall
Onions require consistent moisture and good weed control
Mulch to suppress weeds and retain soil moisture

Problems