Plant Potatoes in Zone 5b
Seed-starting, transplant & harvest dates for USDA Zone 5b
Zone 5b averages 166 frost-free days, running from a last spring frost around April 25 to a first fall frost around October 8. Potatoes needs roughly 90 days from planting out to first harvest, so it uses about 54 percent of that window. Potatoes is a half-hardy crop, which is what decides where in the window it belongs.
Potatoes handles cold soil, so there is no reason to wait for the frost date. Direct sow around Apr 11, roughly 2 weeks before the Zone 5b 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 potatoes for a fall harvest in Zone 5b
Yes. Sow potatoes by July 6 in Zone 5b. That is 94 days before the average first frost, which covers the 90 days to maturity plus about two weeks for the slower growth that comes with shortening days, minus the roughly 10 days potatoes keeps going once light frost arrives.
A fall potato crop works in zone 8 and warmer, planted in late summer from certified seed pieces that have broken dormancy.
Fall dates are counted backward from the Zone 5b average first frost, not forward from a sowing date. See the fall planting calendar by zone for the full method.
Spring vs fall potatoes in Zone 5b
| Planting | Sow or start | In the ground | Harvest |
|---|---|---|---|
| Spring | Apr 11 | Apr 11 | Jul 10 |
| Fall | by Jul 6 | Jul 6 | Oct 4 |
Potatoes in nearby zones
Further reading on potatoes
- Last frost date and what to plant before it
Why potatoes can go out before your last frost, and how far before.
- Best raised garden beds for beginners
Loose, deep soil is most of what root crops need.
- Row covers vs frost blankets
Which cover buys potatoes the extra degrees on a frosty night.
Other crops in Zone 5b
Frequently asked questions
When should I start potatoes in Zone 5b?
Direct sow outdoors around Apr 11.
Can I direct sow potatoes in Zone 5b?
Yes, direct sow around Apr 11.
Can I plant potatoes in the fall in Zone 5b?
Yes. Sow potatoes by July 6 in Zone 5b. That is 94 days before the average first frost, which covers the 90 days to maturity plus about two weeks for the slower growth that comes with shortening days, minus the roughly 10 days potatoes keeps going once light frost arrives.
Will potatoes survive frost in Zone 5b?
Potatoes is a half-hardy crop and keeps going roughly 10 days past the first light frost in Zone 5b. A row cover or a straw mulch buys more.