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how to grow onions from seed

How to Grow Onions from Seed

Growing onions from seed could not be easier! However, be sure to choose varieties suited to your location (you can read more above).
Latin Name Allium cepa
Days to Maturity Depends on Variety
Life Cycle Annual
When Depends on Variety
Light Full sun
FertilizationHeavy feeder
SpacingDepth: 1" Width: 4"


  • Seeds
  • 1020 flat(s)
  • Soilless mix
  • Scissors
  • Soil Amendments *


  • Choose a location with well-draining, fertile soil (pH 6.0–7.0) and full sun. Sandy loam soil is ideal. Prior to planting outside, prepare soil with amendments/compost based on soil needs.*
  • Direct sow: Sow in a 2" wide band, about 2 seeds/inch, 1/4–1/2" deep, in rows 10–12" apart. Thin to 3–4" apart.
  • Transplant: Start seeds indoors, 8–10 weeks before planting outside. In our climate (Zone 4), we start seeds between mid-February and late-March.
  • Transplant: Plant 1" deep, 3–4" apart, in rows 10–12" apart. Alternatively, plant in clumps of three, 1" deep, 10" apart, in rows 10–12" apart. Avoid planting too deep. In our climate (Zone 4), we typically plant out in early May.
  • Water in well at planting and continue to provide 1" water per week.


*We suggest amending your soil based on your individual soil’s unique needs. We usually apply fertilizer and compost prior to planting. If you’d like to see exactly how we fertilize our soil organically (and how you can too), grab our free guide by scrolling to the top of this blog post and sign up. It has lists and links to exact products. Did you find this information helpful? If so, I’d love it if you shared it with your pals.
Keyword Garden, Vegetables
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