When to Plant Onions in North Dakota
North Dakota spans USDA hardiness 3b to 4b (zones 3b to 4b on this page). Plant onions by your local frost date, not the calendar — pick your zone below for exact start-indoors, transplant, and harvest dates.
Jump to: Zone 3b · Zone 4a · Zone 4b
Onions planting calendar for North Dakota, Zone 3b
Average last spring frost
May 20
Average first fall frost
September 15
Direct sow
Feb 25
Projected first harvest
Jun 15
Most onions mature in about 90 to 110 days depending on the variety. Full zone 3 guide (both 3a and 3b) →
Onions planting calendar for North Dakota, Zone 4a
Average last spring frost
May 15
Average first fall frost
September 20
Direct sow
Feb 20
Projected first harvest
Jun 10
Most onions mature in about 90 to 110 days depending on the variety. Full zone 4 guide (both 4a and 4b) →
Onions planting calendar for North Dakota, Zone 4b
Average last spring frost
May 10
Average first fall frost
September 25
Direct sow
Feb 15
Projected first harvest
Jun 5
Most onions mature in about 90 to 110 days depending on the variety. Full zone 4 guide (both 4a and 4b) →
Not sure which half-zone you're in? Set your ZIP in HomeSown for dates tuned to your exact location.
Varieties to grow
8 varieties of onions in the HomeSown library. Tap any for its full grow guide.
Common problems with onions
What to watch for, with identification and treatment for each
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