When to Plant Onions in Zone 5
In USDA zone 5a, start seeds indoors around February 24, transplant or plant outdoors April 7 to July 26, and expect your first harvest around July 26. (5a shown here — see 5a and 5b dates separately below.)
Onions planting calendar for USDA Zone 5a
Average last spring frost
May 5
Average first fall frost
October 1
Start seeds indoors
Feb 24
Transplant outdoors
Apr 7
Projected first harvest
Jul 26
Most onions mature in about 90 to 110 days depending on the variety, needing roughly 149 frost-free days in zone 5a.
Onions planting calendar for USDA Zone 5b
Average last spring frost
April 30
Average first fall frost
October 5
Start seeds indoors
Feb 19
Transplant outdoors
Apr 2
Projected first harvest
Jul 21
Most onions mature in about 90 to 110 days depending on the variety, needing roughly 158 frost-free days in zone 5b.
Not sure whether you're in 5a or 5b? 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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