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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
Onion maggot, thrips, botrytis blight
Varieties
  • Stuttgarter - yellow
  • Ebenezer - yellow
  • Vidalia
  • Barletta - white, mild flavor, slightly flattened bulb, 65-70 days to maturity
  • Cipollotto da Mazzi - scallion type with long white stock
  • Super Star - sweet white, day-length neutral, All-America Selections winner

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