Zone 5a Frost Dates & Planting Calendar

USDA Zone 5a has average coldest-winter lows of −20°F to −15°F. Across the 166 cities we track in this zone, the typical last spring frost is around April 30 and the typical first fall frost around October 8.

Winter low −20°F to −15°F

Typical last frost April 30

Typical first frost October 8

Cities 166

Hardiness zones describe winter cold, not frost timing (why that matters). For dates specific to your town, look up your ZIP code.

Zone 5a Planting Calendar

Vegetables
Crop	Start indoors	Direct sow	Transplant	Fall planting	Maturity	Notes
Tomato	Mar 5 – Mar 19	—	May 7 – May 14	—	60–85 days	Start indoors 6-8 weeks before last frost; transplant out 1-2 weeks after last frost once soil has warmed.
Pepper	Feb 19 – Mar 5	—	May 7 – May 21	—	60–90 days	Slow to germinate; start indoors 8-10 weeks before last frost. Transplant only once nights stay above 55F, 1-3 weeks after last frost.
Eggplant	Feb 19 – Mar 5	—	May 14 – May 21	—	65–85 days	Warm-season crop, similar timing to pepper; needs consistently warm soil (65F+) to transplant.
Cucumber	Apr 2 – Apr 9	May 7 – May 14	May 7 – May 14	—	50–65 days	Can be started indoors 3-4 weeks before transplanting, or direct-sown 1-2 weeks after last frost once soil is warm.
Zucchini	Apr 9 – Apr 16	May 7 – May 21	May 7 – May 14	—	45–55 days	Fast-growing squash; direct sow 1-3 weeks after last frost, or start indoors 2-3 weeks early for a head start.
Winter Squash	Apr 2 – Apr 9	May 7 – May 21	May 7 – May 14	—	80–110 days	Long season; direct sow after soil warms, or start indoors 3-4 weeks before last frost in short-season climates.
Pumpkin	—	May 7 – May 21	—	—	90–120 days	Direct sow 1-3 weeks after last frost; back-time from your first fall frost so the 90-120 day maturity window lands before it.
Watermelon	Apr 2 – Apr 9	—	May 14 – May 21	—	70–90 days	Needs warm soil (65F+); start indoors 3-4 weeks before last frost, transplant 2-3 weeks after last frost.
Cantaloupe	Apr 2 – Apr 9	—	May 14 – May 21	—	70–90 days	Same warm-soil requirements as watermelon; avoid disturbing roots when transplanting.
Corn	—	Apr 30 – May 14	—	—	60–100 days	Direct sow at last frost to 2 weeks after, once soil reaches 60F; does not transplant well. Succession sow every 2 weeks.
Green Bean	—	Apr 30 – May 14	—	—	50–65 days	Direct sow at last frost to 2 weeks after, once soil has warmed; frost-tender, do not rush.
Pea	—	Mar 19 – Apr 2	—	—	55–70 days	Cold-hardy; direct sow 4-6 weeks before last frost as soon as soil can be worked.
Lettuce	—	Apr 2 – Apr 16	—	Aug 13 – Aug 27	45–60 days	Cold-hardy; direct sow 2-4 weeks before last frost. Also transplantable from indoor starts.
Spinach	—	Mar 19 – Apr 2	—	Aug 13 – Aug 27	40–50 days	Very cold-hardy; direct sow 4-6 weeks before last frost as soon as soil can be worked.
Kale	—	Apr 2 – Apr 16	—	Jul 30 – Aug 13	50–65 days	Cold-hardy; direct sow 2-4 weeks before last frost or start indoors for earlier transplants.
Arugula	—	Apr 2 – Apr 16	—	Aug 27 – Sep 3	30–40 days	Fast-growing, cold-tolerant green; direct sow 2-4 weeks before last frost, succession sow every 2-3 weeks.
Swiss Chard	—	Apr 9 – Apr 23	—	—	50–60 days	Fairly cold-hardy; direct sow 1-3 weeks before last frost. Tolerates light frost in fall too.
Broccoli	Mar 12 – Mar 26	—	Apr 9 – Apr 16	Aug 6 – Aug 13	55–80 days	Start indoors 5-7 weeks before last frost; transplant out 2-3 weeks before last frost (hardens off to light frost).
Cauliflower	Mar 12 – Mar 26	—	Apr 16 – Apr 23	Jul 30 – Aug 6	55–85 days	Fussier than broccoli about temperature swings; start indoors 5-7 weeks before last frost, transplant 1-2 weeks before last frost.
Cabbage	Mar 12 – Mar 26	—	Apr 2 – Apr 16	Jul 30 – Aug 13	60–100 days	Cold-hardy; start indoors 5-7 weeks before last frost, transplant 2-4 weeks before last frost.
Brussels Sprouts	Mar 12 – Mar 26	—	Apr 9 – Apr 23	—	90–110 days	Long-season crop best timed to mature after a light fall frost for sweetest flavor; start indoors 5-7 weeks before last frost.
Carrot	—	Apr 2 – Apr 16	—	Jul 16 – Jul 30	60–80 days	Direct sow only (does not transplant); sow 2-4 weeks before last frost, as soon as soil can be worked.
Beet	—	Apr 2 – Apr 16	—	Jul 30 – Aug 13	50–65 days	Direct sow 2-4 weeks before last frost; tolerates light frost.
Radish	—	Mar 26 – Apr 9	—	Aug 27 – Sep 10	22–30 days	Very fast and cold-hardy; direct sow 3-5 weeks before last frost, as soon as soil can be worked.
Turnip	—	Apr 2 – Apr 16	—	Jul 30 – Aug 13	40–60 days	Cold-hardy; direct sow 2-4 weeks before last frost.
Onion	Feb 19 – Mar 5	—	Apr 2 – Apr 16	—	90–120 days	Start seeds indoors 8-10 weeks before last frost (or use sets/transplants); set out 2-4 weeks before last frost, very cold-tolerant as seedlings.
Garlic	—	—	—	Sep 10 – Sep 24	240–270 days	Fall-planted crop only; not planted in spring in most climates.
Potato	—	Apr 2 – Apr 16	—	—	70–120 days	Plant seed potatoes 2-4 weeks before last frost, as soon as soil can be worked and is above 45F; light frost on emerging foliage is usually tolerated.
Sweet Potato	—	—	May 14 – May 28	—	90–120 days	Set out slips 2-4 weeks after last frost once soil is thoroughly warm (65F+); very frost/cold sensitive.
Asparagus	—	—	Apr 2 – Apr 16	—	730–1095 days	Perennial; plant crowns 2-4 weeks before last frost as soon as soil can be worked. Takes 2-3 years to full production.

Herbs
Crop	Start indoors	Direct sow	Transplant	Fall planting	Maturity	Notes
Basil	Mar 19 – Mar 26	—	May 7 – May 14	—	50–70 days	Very frost/cold sensitive; start indoors 5-6 weeks before last frost, transplant only after all danger of frost (1-2 weeks after) and nights stay warm.
Cilantro	—	Apr 9 – Apr 23	—	Aug 13 – Aug 27	45–70 days	Cool-season, bolts in heat; direct sow 1-3 weeks before last frost, succession sow through spring.
Parsley	Mar 5 – Mar 19	—	Apr 16 – Apr 23	—	70–90 days	Slow to germinate; start indoors 6-8 weeks before last frost, transplant 1-2 weeks before last frost (biennial, cold-tolerant).
Dill	—	Apr 9 – Apr 23	—	—	40–60 days	Taprooted, does not transplant well; direct sow 1-3 weeks before last frost, succession sow through summer.
Oregano	Mar 5 – Mar 19	—	Apr 30 – May 7	—	80–90 days	Perennial herb; start indoors 6-8 weeks before last frost, transplant around/just after last frost date.
Thyme	Mar 5 – Mar 19	—	Apr 30 – May 7	—	85–95 days	Perennial herb, slow from seed; start indoors 6-8 weeks before last frost, transplant around/after last frost.

Flowers
Crop	Start indoors	Direct sow	Transplant	Fall planting	Maturity	Notes
Sunflower	—	May 7 – May 21	—	—	70–100 days	Direct sow 1-3 weeks after last frost once soil has warmed; taprooted, resents transplanting.
Zinnia	Apr 2 – Apr 9	May 7 – May 21	May 7 – May 14	—	60–70 days	Frost-tender; direct sow 1-3 weeks after last frost, or start indoors 3-4 weeks early for earlier blooms.
Marigold	Mar 19 – Apr 2	—	May 7 – May 14	—	45–60 days	Frost-tender; start indoors 4-6 weeks before last frost, transplant after all frost danger has passed.
Cosmos	Apr 2 – Apr 9	May 7 – May 21	May 7 – May 14	—	60–90 days	Easy from direct seed 1-3 weeks after last frost; can also start indoors 3-4 weeks early.
Nasturtium	—	May 7 – May 21	—	—	50–65 days	Frost-tender, resents root disturbance; direct sow 1-3 weeks after last frost once soil has warmed.
Dahlia	—	—	May 7 – May 21	—	90–120 days	Plant tubers 1-3 weeks after last frost once soil is warm (60F+); very frost-sensitive.

Date ranges are estimates based on university extension guidelines and this city's NOAA frost normals — not a guarantee. Scroll to see all columns on narrow screens.

Cities in Zone 5a

City	Last frost	First frost
Saint Paul, MN	Apr 24	Oct 16
Madison, WI	May 1	Oct 9
Sioux Falls, SD	May 1	Oct 6
Billings, MT	May 10	Oct 1
Greeley, CO	May 2	Oct 8
Bloomington, MN	Apr 23	Oct 18
Duluth, MN	May 14	Oct 12
Sioux City, IA	Apr 29	Oct 7
Brooklyn Park, MN	Apr 30	Oct 8
Plymouth, MN	Apr 29	Oct 12
Waterloo, IA	Apr 27	Oct 10
Maple Grove, MN	Apr 30	Oct 8
Woodbury, MN	Apr 26	Oct 12
Eagan, MN	Apr 23	Oct 18
Eden Prairie, MN	Apr 23	Oct 14
West Coon Rapids, MN	Apr 30	Oct 8
Coon Rapids, MN	Apr 30	Oct 8
Blaine, MN	May 5	Oct 2
Burnsville, MN	Apr 23	Oct 18
Casper, WY	May 10	Sep 29
Dubuque, IA	Apr 19	Oct 21
La Crosse, WI	Apr 27	Oct 13
Minnetonka, MN	Apr 30	Oct 9
Apple Valley, MN	Apr 27	Oct 10
North La Crosse, WI	Apr 23	Oct 17
Edina, MN	Apr 23	Oct 18
Minnetonka Mills, MN	Apr 29	Oct 12
Saint Louis Park, MN	Apr 29	Oct 12
Bozeman, MT	May 26	Sep 22
Cedar Falls, IA	Apr 27	Oct 10
Mankato, MN	Apr 30	Oct 9
Maplewood, MN	Apr 26	Oct 12
Shakopee, MN	Apr 23	Oct 14
Marion, IA	Apr 28	Oct 12
Richfield, MN	Apr 23	Oct 18
Cottage Grove, MN	Apr 23	Oct 19
Roseville, MN	Apr 28	Oct 8
Inver Grove Heights, MN	Apr 24	Oct 16
Butte, MT	Jun 13	Sep 5
Gillette, WY	May 15	Oct 1

States with Zone 5a cities

Minnesota (60)
Wisconsin (20)
Iowa (14)
Wyoming (13)
South Dakota (11)
Montana (11)
Vermont (9)
Alaska (8)
New York (7)
Maine (3)
Nebraska (3)
Idaho (2)
Michigan (2)
Colorado (1)
Illinois (1)
New Hampshire (1)

Frequently Asked Questions

What is the temperature range for Zone 5a?

Zone 5a is defined by an average annual extreme minimum winter temperature of −20°F to −15°F (USDA 2023 Plant Hardiness Zone Map).

When is the last frost in Zone 5a?

Typically around April 30, though it varies by location. Hardiness zones measure winter cold, not frost timing, so two places in the same zone can have last frosts weeks apart — check your city's page for local dates.

When is the first frost in Zone 5a?

Typically around October 8 across the cities we track in Zone 5a.

Neighboring zones: Zone 4b · Zone 5b · All zones