Seed Starting Calendar for Minnesota

Q: When is the last frost in Minnesota?

It depends on the station. The earliest median last spring freeze in Minnesota is April 15 at La Crescent Dam 7; the latest is June 5 at Hibbing Chisholm Hibbing Airport. A median is a coin flip: at Duluth the last 32°F freeze comes after May 13 in half of years, and has passed by May 29 in 9 of 10 years (NOAA 1991 to 2020 normals).

Q: When can I plant tomatoes outside in Minnesota?

UNH Extension sets tomatoes out 1 to 2 weeks after the last frost, which at Duluth is May 20 to May 27 in 2027. Tomatoes are frost tender, so the date to watch is May 29, when 9 of 10 springs at Duluth have had their last 32°F night. Hardening off starts two weeks before setting out (May 6 to May 20).

Q: What months do I plant vegetables in Minnesota?

University of Minnesota Extension publishes planting months by region (Minnesota). For Minnesota, tomatoes go in during May. Seeds for transplants go in 4 to 10 weeks ahead of those months, depending on the crop.

Q: What does University of Minnesota Extension say about planting dates in Minnesota?

University of Minnesota Extension's Planting the vegetable garden puts it this way: "Wait until after the last frost (mid-to-late May) before transplanting tomatoes, eggplants, peppers, summer squash, basil and similar warm-season crops." The guide is linked below with the date it was read (September 21, 2026).

Q: How many weeks before the last frost do I start peppers and eggplant?

UNH Extension gives 8 to 10 weeks from seed to transplant for both, and sets peppers out 2 weeks after the last frost and eggplant 2 to 3 weeks after, so the sowing date is 6 to 8 weeks before the median last frost. At Duluth that is Mar 18 to Apr 1 for peppers.

Q: How long do seedlings need to harden off?

About two weeks. University of Missouri Extension: "Hardening should be started about two weeks before planting in the garden." University of Minnesota Extension adds that seedlings should go out on a cloudy day or in the late afternoon.

Median last frost from Apr 23 to May 27 across Minnesota

NOAA stations

174

Median last frost, Duluth

May 13

Passed in 9 of 10 years

May 29

Last frost

Last spring frost dates in Minnesota

Minneapolis reaches its median last frost around Apr 23, Duluth on Lake Superior around May 13, and International Falls on the Canadian border around May 29, five weeks behind the Twin Cities.

Three dates per station from the NOAA 1991 to 2020 normals. The median is the date half of springs run past. The last column is the date the last 32°F night has passed by in 9 years out of 10, the one to hold tender transplants for.

Station	Elevation	Early (1 in 10 years later than this)	Median last frost	Passed in 9 of 10 years	Median first fall frost
MinneapolisLower St Anthony Falls, USC00214884	754 ft	Apr 10	Apr 23	May 7	Oct 16
DuluthDuluth, USW00014913	1,428 ft	Apr 29	May 13	May 29	Oct 1
Park Rapids Municipal AirportPark Rapids Municipal Airport, USW00094967	1,434 ft	May 1	May 14	May 27	Sep 25
Grand MaraisGrand Marais, USW00094992	610 ft	May 3	May 22	Jun 18	Oct 9
International FallsIntl Falls Intl Airport, USW00014918	1,183 ft	May 13	May 29	Jun 16	Sep 13

Crop chart

When to start seeds in Minnesota, spring 2027

Counted back from the median last frost at Duluth, May 13. Pick another station to redraw the chart for it.

Start indoorsHarden offSet outSow outdoorsMedian last frostLast freeze passed in 9 of 10 years

Every crop, counted from a median last frost of May 13
Crop	Start indoors	Set out	Sow outdoors	Frost class
Tomato	Mar 25 to Apr 8	May 20 to May 27		Tender, very tender
Pepper	Mar 18 to Apr 1	May 27 to Jun 3		Tender, very tender
Eggplant	Mar 18 to Apr 1	May 27 to Jun 3		Tender, very tender
Basil	Apr 1 to Apr 15	May 27 to Jun 3		Tender
Celery	Feb 18 to Mar 4	May 13 to May 20		Tender
Cucumber	Apr 22 to Apr 29	May 20 to May 27	May 13 to May 20	Tender
Summer squash	Apr 29 to May 6	May 27 to Jun 3	May 13 to May 20	Tender
Winter squash	Apr 29 to May 6	May 27 to Jun 3	May 27 to Jun 3	Tender, very tender
Pumpkin	Apr 29 to May 6	May 27 to Jun 3	May 27 to Jun 3	Tender, very tender
Melon (cantaloupe)	Apr 29 to May 6	May 27 to Jun 3		Tender, very tender
Watermelon	Apr 22 to May 6	May 27 to Jun 3		Tender, very tender
Onion (from seed)	Feb 4 to Feb 18	Apr 15 to Apr 22		Hardy
Leek	Feb 4 to Feb 18	Apr 15 to Apr 22		Hardy
Parsley	Feb 11 to Feb 18	Apr 22 to Apr 29		Half-hardy
Broccoli	Mar 4 to Mar 18	Apr 15 to Apr 29		Hardy
Brussels sprouts	Mar 4 to Mar 18	Apr 15 to Apr 29		Hardy
Cabbage	Mar 4 to Mar 18	Apr 15 to Apr 22		Hardy
Cauliflower	Mar 18 to Apr 1	Apr 29 to May 6		Half-hardy
Kale	Mar 4 to Mar 18	Apr 15 to Apr 22		Hardy
Lettuce	Mar 11 to Mar 18	Apr 15 to Apr 22		Hardy
Swiss chard	Mar 18 to Apr 1	Apr 29 to May 6	Apr 15 to Apr 22	Half-hardy
Spinach	Feb 18 to Mar 4	Apr 1 to Apr 22	Apr 15 to Apr 29	Hardy
Peas			Apr 15 to Apr 29	Hardy
Radish			Apr 15 to Apr 29	Hardy
Carrot			Apr 29 to May 13	Half-hardy
Beet			Apr 29 to May 13	Half-hardy
Beans			May 13 to May 20	Tender
Sweet corn			May 13 to May 20	Tender

Six square pots of dark compost seen from above, each holding a single seedling with two narrow seed leaves — Tomato seedlings at the seed leaf stage, one to a pot. The University of Minnesota Extension holds off on fertilizer until a seedling has several sets of true leaves, then feeds at quarter strength once a week. “Tomato Seedlings (49768696597)” by Amanda Slater from Coventry, West Midlands, UK, CC BY-SA 2.0

Extension guide

What University of Minnesota Extension advises

University of Minnesota Extension publishes the planting guide Minnesota gardeners work from, Planting the vegetable garden.

“Wait until after the last frost (mid-to-late May) before transplanting tomatoes, eggplants, peppers, summer squash, basil and similar warm-season crops.”

University of Minnesota Extension, Planting the vegetable garden, quoted exactly.

“In Minnesota, annual flowers and heat-loving vegetables such as tomato, pepper and eggplant are usually started in early spring.”

University of Minnesota Extension, Starting seeds indoors, quoted exactly.

“Early April | 5-6 weeks | Flowers: amaranthus, aster, baby's breath, bachelor buttons, balsam, calendula, celosia, cornflower, four o'clock, marigold (French and gem), morning glory, nasturtium, ornamental basil, ornamental kale, portulaca, strawflower Vegetables: tomatoes”

University of Minnesota Extension, on tomato, quoted exactly.

“Cabbage and broccoli intended for fall crops may be started indoors in June or July.”

University of Minnesota Extension, on cabbage, quoted exactly.

“You can seed cucumbers, pumpkins and watermelons earlier by placing hot caps over the soil one week before planting.”

University of Minnesota Extension, on cucumber, quoted exactly.

“If soil temperatures are between 40 and 50 degrees F, you can direct-seed peas, spinach, lettuce, and radish.”

University of Minnesota Extension, on peas, quoted exactly.

Planting months

University of Minnesota Extension planting months for Minnesota

The extension also publishes planting months by region. Each filled cell is a month the guide gives for planting that crop.

Minnesota

Crop	Apr	May	Jun	Jul	Aug
cabbage	Apr		Jun
broccoli	Apr		Jun
brussels sprouts	Apr		Jun
cauliflower	Apr		Jun
onion	Apr
parsley	Apr
spinach	Apr				Aug
peas	Apr	May
radish	Apr	May			Aug
carrots	Apr	May	Jun
beets	Apr	May	Jun
kale	Apr	May	Jun	Jul
swiss chard		May
cucumbers		May	Jun
celery		May
muskmelon		May
pumpkin		May
tomatoes		May
watermelon		May
sweet corn		May	Jun
snap beans		May	Jun	Jul
eggplant			Jun
pepper			Jun

Planting months from University of Minnesota Extension, Planting the vegetable garden, read 2026-09-21. Tomatoes in Minnesota: May.

A gardener kneeling beside a raised bed setting a young tomato plant into dark soil, an empty nursery pot beside her — Setting out a tomato in June at a community garden. Tender crops go out after the last frost, and after a week or two of hardening off outdoors. “Volunteer planting heirloom tomato (4704185147)”, Pacific Southwest Region 5, Public domain

Seed starting questions for Minnesota

When should I start seeds indoors in Minnesota?

Count back from the median last frost where you garden. At Duluth (Duluth) that date is May 13, so for spring 2027 onions start indoors Feb 4 to Feb 18, peppers Mar 18 to Apr 1 and tomatoes Mar 25 to Apr 8. Across Minnesota's 174 NOAA stations the median last frost runs from Apr 23 to May 27 for the middle 90 percent, so a garden near Hibbing Chisholm Hibbing Airport starts later than one near La Crescent Dam 7.

When is the last frost in Minnesota?

When can I plant tomatoes outside in Minnesota?

What months do I plant vegetables in Minnesota?

What does University of Minnesota Extension say about planting dates in Minnesota?

How many weeks before the last frost do I start peppers and eggplant?

How long do seedlings need to harden off?

Why do seed starting dates differ across Minnesota?

Frost dates from NOAA NCEI U.S. Climate Normals 1991-2020, annual/seasonal, by station (v1.0.1). Planting guidance from University of Minnesota Extension, quoted exactly. Seed starting weeks from UNH Cooperative Extension. Compiled 2026-09-21.

First frost in MinnesotaThe other end of the season: when fall frost ends the tender crops.Soil temperatureBeans, corn and squash sown direct wait on warm soil as well as the last frost.Minnesota lawn care calendarSpring seeding, feeding and mowing dates on the same climate.Fall planting calendarGarlic, cool season crops and a second sowing window in the fall.Frost dates by ZIPFirst and last frost odds for any address.