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When to plant in Stillwater, MN

USDA Zone 4b

Everything below — frost dates, hardiness zone, and what to plant when in Stillwater, Minnesota — is derived from the closest NOAA station with complete climate normals.

Zone 4b is cold — in Stillwater, most perennials must be fully hardy, and your frost dates set a tight window for tender annual vegetables.

Station · STILLWATER 2SW · 2.2 km
Last spring frost
April 30
50% chance · 32°F
First fall frost
October 11
50% chance · 32°F
Growing season
164 days
frost-free
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Frost calendar for StillwaterA year-band showing 32°F frost risk from January to December for Stillwater: last spring frost around April 30, first fall frost around October 11, about 164 frost-free days between.
Shaded months carry frost risk; the clear span is the average frost-free season.

Frost probability

STILLWATER 2SW · 1991–2020

The date the last spring and first fall frost occur, by threshold and probability. A 90% date is later in spring — and earlier in fall — than a 10% date; the 50% · 32°F row is what most gardeners plan around. These are Stillwater’s own odds, recorded at STILLWATER 2SW.

Frost-probability curves for StillwaterProbability of the last spring frost and first fall frost by date at 32°F. The last spring frost is most likely around April 30 and the first fall frost around October 11, giving about 164 frost-free days.
Last spring frostFirst fall frostbold = 32°F · thin = 28°F / 36°F · dot = 50% date · band = 10–90% window
ThresholdSPRING 10%SPRING 50%SPRING 90%FALL 10%FALL 50%FALL 90%
36°FMay 23May 8Apr 26Sep 20Oct 2Oct 14
32°FMay 13Apr 30Apr 17Sep 28Oct 11Oct 23
28°FMay 2Apr 20Apr 6Oct 10Oct 23Nov 4

Download this table as CSV ↓ — every threshold and probability, plus this city’s planting-window dates.

What to plant now

TODAY · JULY 19
Fall sowopen now
Rutabaga
July 5July 19
Fall sowopen now
Broccoli
July 19August 2
Fall sowopen now
Cabbage
July 19August 2
Fall sowopen now
Carrot
July 19August 2
Fall sowopen now
Cauliflower
July 19August 2
Fall sowopen now
Napa Cabbage
July 19August 16
Fall sowin 14 days
Beet
August 2August 16
Fall sowin 14 days
Collards
August 2August 30
Fall sowin 14 days
Endive
August 2August 16
Fall sowin 14 days
Escarole
August 2August 16
Fall sowin 14 days
Fennel (Bulb)
August 2August 16
Fall sowin 14 days
Kale
August 2August 30
Fall sowin 14 days
Kohlrabi
August 2August 30
Fall sowin 14 days
Peas
August 2August 16
Fall sowin 14 days
Radicchio
August 2August 16
Fall sowin 14 days
Swiss Chard
August 2August 16
Fall sowin 14 days
Turnip
August 2August 30
Fall sowin 28 days
Arugula
August 16September 13
Fall sowin 28 days
Bok Choy
August 16August 30
Fall sowin 28 days
Chervil
August 16September 13
Fall sowin 28 days
Cilantro
August 16September 13
Fall sowin 28 days
Claytonia (Miner's Lettuce)
August 16September 13
Fall sowin 28 days
Corn Salad (Mâche)
August 16September 13
Fall sowin 28 days
Gai Lan (Chinese Broccoli)
August 16August 30
Fall sowin 28 days
Lettuce
August 16September 13
Fall sowin 28 days
Mizuna
August 16September 13
Fall sowin 28 days
Mustard Greens
August 16September 13
Fall sowin 28 days
Radish
August 16September 13
Fall sowin 28 days
Shungiku (Edible Chrysanthemum)
August 16August 30
Fall sowin 28 days
Spinach
August 16September 13
Fall sowin 28 days
Tatsoi
August 16September 13

Add these crops to your calendar (.ics) ↓

Full-year planting calendar

Start indoorsTransplantDirect sowFall sow

Each bar is the exact window to take a planting action in Stillwater, drawn to the day from the local frost dates. The dashed line is today.

Nearby weather stations

3 within 20 km · complete 32°F normals

When stations disagree by more than a few days, that spread is real microclimate variation — elevation, water, urban heat. Judge which station best matches your own yard.

STILLWATER 2SW
Primary
2 km · 274 m elevation
SPRING
Apr 30
FALL
Oct 11
STILLWATER 1 SE
3 km · 216 m elevation
SPRING
Apr 22
FALL
Oct 19
ST PAUL
20 km · 274 m elevation
SPRING
Apr 26
FALL
Oct 12

Stillwater planting FAQ

When is the last spring frost in Stillwater, MN?

Stillwater's average last spring frost falls near April 30 — the 50% mark at 32°F in the 1991–2020 normals. Hold tender transplants until the risk has passed, then plant out.

When is the first fall frost in Stillwater, MN?

The first fall frost in Stillwater typically arrives around October 11 (50% probability at 32°F). Harvest or protect frost-sensitive crops before then.

What hardiness zone is Stillwater in?

Stillwater is in USDA hardiness zone 4b. In zone 4b, winters are cold — pick cold-hardy varieties and protect tender crops.

How long is the growing season in Stillwater?

There are roughly 164 frost-free days in Stillwater (a moderate growing season), running from the average last frost around April 30 to the first fall frost near October 11.

When should I plant tomatoes in Stillwater?

In Stillwater, start tomato seeds indoors around March 5–March 19, then transplant seedlings outdoors around May 7 once the danger of frost has passed.

Planting reminders

Never miss a window in Stillwater

An email when it’s time to start seeds, transplant, and sow — timed to Stillwater’s frost dates. Double opt-in, one-click unsubscribe, no spam.

Nearby cities

8 within reach

Frost dates recorded at STILLWATER 2SW, 2 km from the city center · 1991–2020 NOAA climate normals · zone from the USDA/PRISM 2023 map. How we compute this.

Cite this page
BlissGarden. "When to Plant in Stillwater, MN — Frost Dates & Zone 4b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00218039. Retrieved from https://blissgarden.com/minnesota/stillwater.
When to Plant in Stillwater, MN — Frost Dates & Zone 4b — BlissGarden