Zone 6a Frost Dates & Planting Calendar

USDA Zone 6a has average coldest-winter lows of −10°F to −5°F. Across the 486 cities we track in this zone, the typical last spring frost is around April 26 and the typical first fall frost around October 20.

Winter low −10°F to −5°F

Typical last frost April 26

Typical first frost October 20

Cities 486

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

Zone 6a Planting Calendar

Vegetables
Crop	Start indoors	Direct sow	Transplant	Fall planting	Maturity	Notes
Tomato	Mar 1 – Mar 15	—	May 3 – May 10	—	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 15 – Mar 1	—	May 3 – May 17	—	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 15 – Mar 1	—	May 10 – May 17	—	65–85 days	Warm-season crop, similar timing to pepper; needs consistently warm soil (65F+) to transplant.
Cucumber	Mar 29 – Apr 5	May 3 – May 10	May 3 – May 10	—	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 5 – Apr 12	May 3 – May 17	May 3 – May 10	—	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	Mar 29 – Apr 5	May 3 – May 17	May 3 – May 10	—	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 3 – May 17	—	—	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	Mar 29 – Apr 5	—	May 10 – May 17	—	70–90 days	Needs warm soil (65F+); start indoors 3-4 weeks before last frost, transplant 2-3 weeks after last frost.
Cantaloupe	Mar 29 – Apr 5	—	May 10 – May 17	—	70–90 days	Same warm-soil requirements as watermelon; avoid disturbing roots when transplanting.
Corn	—	Apr 26 – May 10	—	—	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 26 – May 10	—	—	50–65 days	Direct sow at last frost to 2 weeks after, once soil has warmed; frost-tender, do not rush.
Pea	—	Mar 15 – Mar 29	—	—	55–70 days	Cold-hardy; direct sow 4-6 weeks before last frost as soon as soil can be worked.
Lettuce	—	Mar 29 – Apr 12	—	Aug 25 – Sep 8	45–60 days	Cold-hardy; direct sow 2-4 weeks before last frost. Also transplantable from indoor starts.
Spinach	—	Mar 15 – Mar 29	—	Aug 25 – Sep 8	40–50 days	Very cold-hardy; direct sow 4-6 weeks before last frost as soon as soil can be worked.
Kale	—	Mar 29 – Apr 12	—	Aug 11 – Aug 25	50–65 days	Cold-hardy; direct sow 2-4 weeks before last frost or start indoors for earlier transplants.
Arugula	—	Mar 29 – Apr 12	—	Sep 8 – Sep 15	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 5 – Apr 19	—	—	50–60 days	Fairly cold-hardy; direct sow 1-3 weeks before last frost. Tolerates light frost in fall too.
Broccoli	Mar 8 – Mar 22	—	Apr 5 – Apr 12	Aug 18 – Aug 25	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 8 – Mar 22	—	Apr 12 – Apr 19	Aug 11 – Aug 18	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 8 – Mar 22	—	Mar 29 – Apr 12	Aug 11 – Aug 25	60–100 days	Cold-hardy; start indoors 5-7 weeks before last frost, transplant 2-4 weeks before last frost.
Brussels Sprouts	Mar 8 – Mar 22	—	Apr 5 – Apr 19	—	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	—	Mar 29 – Apr 12	—	Jul 28 – Aug 11	60–80 days	Direct sow only (does not transplant); sow 2-4 weeks before last frost, as soon as soil can be worked.
Beet	—	Mar 29 – Apr 12	—	Aug 11 – Aug 25	50–65 days	Direct sow 2-4 weeks before last frost; tolerates light frost.
Radish	—	Mar 22 – Apr 5	—	Sep 8 – Sep 22	22–30 days	Very fast and cold-hardy; direct sow 3-5 weeks before last frost, as soon as soil can be worked.
Turnip	—	Mar 29 – Apr 12	—	Aug 11 – Aug 25	40–60 days	Cold-hardy; direct sow 2-4 weeks before last frost.
Onion	Feb 15 – Mar 1	—	Mar 29 – Apr 12	—	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 22 – Oct 6	240–270 days	Fall-planted crop only; not planted in spring in most climates.
Potato	—	Mar 29 – Apr 12	—	—	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 10 – May 24	—	90–120 days	Set out slips 2-4 weeks after last frost once soil is thoroughly warm (65F+); very frost/cold sensitive.
Asparagus	—	—	Mar 29 – Apr 12	—	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 15 – Mar 22	—	May 3 – May 10	—	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 5 – Apr 19	—	Aug 25 – Sep 8	45–70 days	Cool-season, bolts in heat; direct sow 1-3 weeks before last frost, succession sow through spring.
Parsley	Mar 1 – Mar 15	—	Apr 12 – Apr 19	—	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 5 – Apr 19	—	—	40–60 days	Taprooted, does not transplant well; direct sow 1-3 weeks before last frost, succession sow through summer.
Oregano	Mar 1 – Mar 15	—	Apr 26 – May 3	—	80–90 days	Perennial herb; start indoors 6-8 weeks before last frost, transplant around/just after last frost date.
Thyme	Mar 1 – Mar 15	—	Apr 26 – May 3	—	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 3 – May 17	—	—	70–100 days	Direct sow 1-3 weeks after last frost once soil has warmed; taprooted, resents transplanting.
Zinnia	Mar 29 – Apr 5	May 3 – May 17	May 3 – May 10	—	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 15 – Mar 29	—	May 3 – May 10	—	45–60 days	Frost-tender; start indoors 4-6 weeks before last frost, transplant after all frost danger has passed.
Cosmos	Mar 29 – Apr 5	May 3 – May 17	May 3 – May 10	—	60–90 days	Easy from direct seed 1-3 weeks after last frost; can also start indoors 3-4 weeks early.
Nasturtium	—	May 3 – May 17	—	—	50–65 days	Frost-tender, resents root disturbance; direct sow 1-3 weeks after last frost once soil has warmed.
Dahlia	—	—	May 3 – May 17	—	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 6a

City	Last frost	First frost
Denver, CO	Apr 30	Oct 12
Milwaukee, WI	Apr 26	Oct 22
Omaha, NE	Apr 18	Oct 21
Colorado Springs, CO	May 3	Oct 8
Aurora, CO	May 4	Oct 8
Lincoln, NE	Apr 24	Oct 13
Fort Wayne, IN	Apr 24	Oct 21
Rochester, NY	Apr 24	Oct 25
Worcester, MA	Apr 23	Oct 21
Grand Rapids, MI	May 6	Oct 10
Lakewood, CO	May 3	Oct 7
Joliet, IL	Apr 19	Oct 25
Syracuse, NY	Apr 29	Oct 19
Thornton, CO	May 2	Oct 11
Columbia, MO	Apr 5	Oct 31
Ann Arbor, MI	May 5	Oct 10
Westminster, CO	May 2	Oct 11
Arvada, CO	May 5	Oct 5
Peoria, IL	Apr 16	Oct 23
Springfield, IL	Apr 15	Oct 22
North Peoria, IL	Apr 16	Oct 23
Lansing, MI	May 1	Oct 13
Manchester, NH	Apr 30	Oct 11
Centennial, CO	May 5	Oct 8
Pueblo, CO	Apr 30	Oct 9
Boulder, CO	May 6	Oct 5
South Bend, IN	Apr 23	Oct 23
Albany, NY	Apr 27	Oct 15
Kenosha, WI	Apr 19	Oct 26
Flint, MI	May 6	Oct 10
Highlands Ranch, CO	May 5	Oct 8
West Albany, NY	Apr 27	Oct 15
Carmel, IN	Apr 21	Oct 21
Waukegan, IL	Apr 30	Oct 19
Nashua, NH	Apr 30	Oct 12
Canton, MI	Apr 24	Oct 24
Champaign, IL	Apr 15	Oct 24
Cicero, IL	Apr 11	Oct 31
Farmington Hills, MI	May 1	Oct 17
Bloomington, IL	Apr 21	Oct 20

States with Zone 6a cities

Illinois (134)
Indiana (65)
Michigan (57)
Ohio (51)
Colorado (38)
New York (30)
Massachusetts (24)
New Hampshire (17)
Wisconsin (14)
Pennsylvania (11)
Missouri (10)
Utah (10)
Nebraska (8)
Maine (6)
Connecticut (4)
Iowa (3)
Kansas (2)
Arizona (1)
New Mexico (1)

Frequently Asked Questions

What is the temperature range for Zone 6a?

Zone 6a is defined by an average annual extreme minimum winter temperature of −10°F to −5°F (USDA 2023 Plant Hardiness Zone Map).

When is the last frost in Zone 6a?

Typically around April 26, 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 6a?

Typically around October 20 across the cities we track in Zone 6a.

Neighboring zones: Zone 5b · Zone 6b · All zones