When to Plant Kabocha Squash in Zone 3
In USDA zone 3a, start seeds indoors around May 9, transplant or plant outdoors June 13 to September 10. (3a shown here — see 3a and 3b dates separately below.)
Kabocha Squash planting calendar for USDA Zone 3a
Average last spring frost
May 30
Average first fall frost
September 10
Start seeds indoors
May 9
Transplant outdoors
Jun 13
Kabocha Squash needs about 95 days to mature — longer than zone 3atypically stays frost-free, so it likely won't reliably ripen there outdoors without a head start indoors or season extension.
Kabocha Squash planting calendar for USDA Zone 3b
Average last spring frost
May 20
Average first fall frost
September 15
Start seeds indoors
Apr 29
Transplant outdoors
Jun 3
Projected first harvest
Sep 6
Kabocha Squash is ready to harvest in about 95 days, needing roughly 118 frost-free days in zone 3b.
Not sure whether you're in 3a or 3b? Set your ZIP in HomeSown for dates tuned to your exact location.
Varieties to grow
1 variety of kabocha squash in the HomeSown library. Tap any for its full grow guide.
Common problems with kabocha squash
What to watch for, with identification and treatment for each
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