Plant Carrots in Zone 3b
Seed-starting, transplant & harvest dates for USDA Zone 3b
Zone 3b averages 128 frost-free days, running from a last spring frost around May 13 to a first fall frost around September 18. Carrots needs roughly 70 days from planting out to first harvest, so it uses about 55 percent of that window. Carrots is a hardy crop, which is what decides where in the window it belongs.
Carrots handles cold soil, so there is no reason to wait for the frost date. Direct sow around Apr 29, roughly 2 weeks before the Zone 3b last frost, as soon as the ground is workable. Sowing at the last frost instead costs you the coolest and best part of the season.
Planting carrots for a fall harvest in Zone 3b
Yes. Sow carrots by July 24 in Zone 3b. That is 56 days before the average first frost, which covers the 70 days to maturity plus about two weeks for the slower growth that comes with shortening days, minus the roughly 28 days carrots keeps going once light frost arrives.
Carrots convert starch to sugar in cold soil, so fall carrots taste noticeably sweeter. Under a straw mulch they hold in the ground well past the first hard freeze.
Fall dates are counted backward from the Zone 3b average first frost, not forward from a sowing date. See the fall planting calendar by zone for the full method.
Spring vs fall carrots in Zone 3b
| Planting | Sow or start | In the ground | Harvest |
|---|---|---|---|
| Spring | Apr 29 | Apr 29 | Jul 8 |
| Fall | by Jul 24 | Jul 24 | Oct 2 |
Carrots in nearby zones
Further reading on carrots
- Can you plant carrots in September?
The September cutoff for a fall carrot crop, zone by zone.
- Cold frame gardening by zone
How a cold frame keeps carrots producing into winter, and when to sow it.
- Last frost date and what to plant before it
Why carrots can go out before your last frost, and how far before.
Other crops in Zone 3b
Frequently asked questions
When should I start carrots in Zone 3b?
Direct sow outdoors around Apr 29.
Can I direct sow carrots in Zone 3b?
Yes, direct sow around Apr 29.
Can I plant carrots in the fall in Zone 3b?
Yes. Sow carrots by July 24 in Zone 3b. That is 56 days before the average first frost, which covers the 70 days to maturity plus about two weeks for the slower growth that comes with shortening days, minus the roughly 28 days carrots keeps going once light frost arrives.
Will carrots survive frost in Zone 3b?
Carrots is a hardy crop and keeps going roughly 28 days past the first light frost in Zone 3b. A row cover or a straw mulch buys more.