Brought to you by garden.gg Brought to you by garden.gg USDA zone 3 is a cold continental climate with long, harsh winters (annual minimums of -40 to -30°F) and a short, intense growing season of roughly 90-115 frost-free days. Warm spells arrive late and frost returns early, so heat-loving crops require indoor starting and season-extension to mature.
Zone 3 takes in Duluth and International Falls, Caribou in northern Maine, the northern plains of North Dakota and Montana, and high-elevation valleys in the Wyoming and Colorado Rockies. Winter lows hit -40°F and the 105-day season leaves no slack: a tomato transplanted a week late may never ripen. The compensation is 16-hour June days that push peas, brassicas, and root crops hard.
States & regions in Zone 3: Northern Minnesota (Duluth, International Falls), Northern North Dakota & Montana (Bismarck, Glasgow), Northern Wisconsin, Interior/northern Maine (Caribou), Northern New Hampshire & Vermont mountains, High-elevation Wyoming & Colorado Rockies, Upper Michigan (interior)
With just 120 frost-free days, zone 3 gardeners can't afford to guess. Every week matters when you're racing against September frost. That's why tracking your planting dates, frost alerts, and harvest windows isn't optional — it's survival.
Pro tip: Start seeds indoors in March to get a head start. Use season extenders like cold frames and row covers to squeeze out extra weeks on both ends.
Start tracking your zone 3 garden — free
The right crops and methods for each season, based on zone 3's climate and frost timing.
Spring in zone 3 is short and unpredictable, with hard frosts possible into early June. Cold-tolerant greens, roots, and brassicas go in as soon as soil can be worked (mid-to-late April), while warm-season crops are started indoors under lights and held until after the last frost.
Late Feb - Mar
Long-day varieties only; start 10-12 weeks before last frost, transplant mid-May.
Late Feb - Mar
Slow to size up; needs the longest possible season.
Mar
Start 10-12 weeks early; transplant after frost danger passes.
Mar
Long-season root; start indoors with celery.
Mar - Early Apr
Start 8-10 weeks before last frost; choose early, short-season varieties.
Mar - Early Apr
Needs bottom heat; pick the earliest cultivars for zone 3.
Late Mar - Apr
Start 6-8 weeks early; favor early determinate/short-season types (e.g. 55-65 day).
Late Mar - Apr
Start with tomatoes; plant at least two for pollination.
Late Mar - Apr
Treat like tomatillo; reliable in short seasons once established.
Late Mar - Apr
Start indoors, transplant early May; tolerates light frost.
Late Mar - Apr
Start indoors; keep growth steady to avoid buttoning.
Late Mar - Apr
Hardy transplant; set out early-to-mid May.
Late Mar - Apr
Long-season; start early so sprouts size up before hard fall frost.
Apr
Can also be direct-sown; transplants give an earlier crop.
Apr
Transplant after frost to reduce bolting risk.
Apr
Very frost-tender; hold indoors until soil and nights warm (June).
Mar - Apr
Slow to germinate; start early or direct-sow late April.
Mar - Apr
Cold-hardy; transplant early and it shrugs off light frost.
Late Apr - Early May
Sow as soon as soil is workable; tolerates frost.
Late Apr - Early May
Very cold-tolerant; one of the earliest sowings.
Late Apr - Early May
Likes cool weather; sow early before heat.
Late Apr - May
Sow early; bolts fast once days lengthen and warm.
Late Apr - May
Succession-sow every 2 weeks; very frost-tolerant.
Late Apr - May
Fast cool-season green; bolts in summer heat.
Late Apr - May
Quick, cold-hardy; sow as soon as soil works.
Late Apr - May
Matures in 3-4 weeks; ideal early crop.
Early - Mid May
Sow once soil reaches ~45°F; keep seedbed moist.
Early - Mid May
Cold-tolerant; greens and roots both usable.
Late Apr - May
Fast cool-season root; sow early.
Early - Mid May
Slow germinator; needs full season, sweetens after frost.
Late Apr - May
Extremely cold-hardy; direct-sow or transplant.
Early May
Sow after worst frosts; productive all season.
Early - Mid May
Plant seed potatoes 2-3 weeks before last frost; hill against late frost.
Late Apr - May
Plant sets in early spring for summer harvest.
Late Apr - May
Quick and cold-tolerant; succession-sow.
Late Apr - May
Cool-season; bolts in heat, so sow early and succession.
May
Direct-sow after frost; self-seeds readily.
Late Apr - May
Hardy annual; tolerates cool soil and light frost.
Late Apr - May
Sow early in cool soil; provide support.
Summer is the prime warm-season window, but it is brief and nights stay cool. After the last frost (late May/early June) set out all heat-lovers and keep succession-sowing fast greens and roots; aim to have warm crops well-established by mid-June to beat the early-September frost.
Early - Mid Jun
Transplant only after frost risk passes; use Wall O' Water or row cover early.
Early - Mid Jun
Wait for warm nights (>50°F); black mulch boosts soil heat.
Mid Jun
Most heat-demanding nightshade; cloche or low tunnel helps.
Early - Mid Jun
Plant in pairs for fruit set.
Early - Mid Jun
Sprawling; give room and harvest fallen husks.
Mid Jun
Cold-sensitive; do not set out until nights stay above 50°F.
Early Jun
Direct-sow in warm soil; very productive in short seasons.
Early Jun
Fast-maturing; sow after frost on warm soil.
Early Jun
Choose early types (e.g. acorn, buttercup); may also start indoors in May to gain time.
Early Jun
Pick short-season varieties; start indoors late May for larger types.
Early Jun
Short-season pie pumpkins ripen reliably; cure before storage.
Early - Mid Jun
Warm soil only; row cover speeds early growth.
Early Jun
Choose early/short-season hybrids; sow in blocks for pollination.
Early - Mid Jun
Frost-tender; sow once soil warms; quick to harvest.
Early - Mid Jun
Sow on warm soil with a trellis.
Early - Mid Jun
Pick early-maturing edamame varieties for zone 3.
Early - Mid Jun
Handles cool nights better than common beans; ornamental too.
Mid Jun
Marginal; start indoors May, transplant onto black plastic + tunnel.
Mid Jun
Only short-season icebox types under plastic/tunnel will ripen.
Early - Mid Jun
Heat-loving green; sow after soil warms.
Late May - Jun
Direct-sow; choose shorter-season varieties for seed.
Early - Mid Jun
Frost-tender; start indoors or transplant after last frost.
Early - Mid Jun
Plant after frost; good pest companion.
Early Jun
Easy from direct seed once frost has passed.
Early Jun
Direct-sow after frost; edible flowers and leaves.
Early Jun
Direct-sow; attracts pollinators, self-seeds.
Jun - Jul
Succession-sow heat-tolerant types in part shade through summer.
Jun
Second sowing for fall storage.
Jun
Main storage sowing; harvest after fall frosts for sweetness.
Fall arrives fast, with the first frost typically around mid-September. The season belongs to cold-hardy greens and roots that sweeten in cool weather, plus garlic planting; protect tender survivors with row cover and harvest storage crops before hard freezes.
Late Sep - Oct
Plant cloves 4-6 weeks before ground freezes; mulch heavily for winter.
Late Jul - Aug
Fall sowing; very frost-hardy and can overwinter under mulch.
Late Jul - Aug
Cool-weather flush; cover during early frosts to extend.
Aug
Fast fall green; flavor improves in cool weather.
Aug
Cold-hardy mustard for fall salads.
Aug
Very cold-tolerant rosette green for fall.
Aug
Fall sowing avoids spring bolting; protect from early frost.
Aug
Quick fall crop; sweeter after light frost.
Aug - Early Sep
Fast fall crop; tolerates frost.
Late Jul - Aug
Roots and greens both improve after frost.
Aug - Sep
Extremely cold-hardy; can overwinter under snow.
Aug - Sep
Cold-hardy salad green; overwinters in cold frame.
Winter is not an outdoor growing season in zone 3 — the ground freezes solid and snow cover lasts for months. Work moves indoors: planning the next garden, ordering seed, starting long-season transplants under lights late in the period, and protecting overwintering garlic and perennials under mulch and snow.
Late Feb
Begin long-day onion seedlings indoors under lights for a May transplant.
Late Feb
Start indoors with onions; needs the longest lead time.
Late Feb
Slow grower; sow indoors at winter's end.
Start-indoors, direct-sow, transplant, and harvest windows for every crop in zone 3.
| Plant | Start Indoors | Direct Sow | Transplant | Harvest | Notes |
|---|---|---|---|---|---|
| Amaranth (Leaf) | — | Early - Mid Jun | — | — | Heat-loving green; sow after soil warms. |
| Arugula | — | Late Apr - May | — | — | Fast fall green; flavor improves in cool weather. |
| Beet | — | Jun | — | Sep - Oct | Cold-tolerant; greens and roots both usable. |
| Bok Choy / Pak Choi | — | Aug | — | — | Fall sowing avoids spring bolting; protect from early frost. |
| Broccoli | Late Mar - Apr | — | — | — | Start indoors, transplant early May; tolerates light frost. |
| Brussels Sprouts | Late Mar - Apr | — | — | Sep - Oct | Long-season; start early so sprouts size up before hard fall frost. |
| Bush Bean | — | Early - Mid Jun | — | — | Frost-tender; sow once soil warms; quick to harvest. |
| Cabbage | Late Mar - Apr | — | — | Sep - Oct | Hardy transplant; set out early-to-mid May. |
| Carrot | — | Jun | — | Sep - Oct | Sow once soil reaches ~45°F; keep seedbed moist. |
| Cauliflower | Late Mar - Apr | — | — | — | Start indoors; keep growth steady to avoid buttoning. |
| Celeriac | Mar | — | — | — | Long-season root; start indoors with celery. |
| Celery | Mar | — | — | — | Start 10-12 weeks early; transplant after frost danger passes. |
| Claytonia (Miner's Lettuce) | — | Aug - Sep | — | — | Cold-hardy salad green; overwinters in cold frame. |
| Collards | — | — | — | Sep - Oct | — |
| Corn (Sweet) | — | Early Jun | — | — | Choose early/short-season hybrids; sow in blocks for pollination. |
| Cucumber | — | Early - Mid Jun | — | — | Warm soil only; row cover speeds early growth. |
| Edamame (Soybean) | — | Early - Mid Jun | — | — | Pick early-maturing edamame varieties for zone 3. |
| Eggplant | Mar - Early Apr | — | Mid Jun | — | Most heat-demanding nightshade; cloche or low tunnel helps. |
| Fava Bean | — | Late Apr - Early May | — | — | Likes cool weather; sow early before heat. |
| Garden Pea | — | Late Apr - Early May | — | — | Sow as soon as soil is workable; tolerates frost. |
| Garlic | — | — | Late Sep - Oct | — | Plant cloves 4-6 weeks before ground freezes; mulch heavily for winter. |
| Husk-less / Pie Pumpkin | — | Early Jun | — | — | Short-season pie pumpkins ripen reliably; cure before storage. |
| Kale | — | Late Apr - May | — | Sep - Oct | Extremely cold-hardy; direct-sow or transplant. |
| Kohlrabi | Apr | — | — | — | Can also be direct-sown; transplants give an earlier crop. |
| Leek | Late Feb - Mar | — | — | Sep - Oct | Slow to size up; needs the longest possible season. |
| Lettuce | — | Late Jul - Aug | — | — | Cool-weather flush; cover during early frosts to extend. |
| Mizuna | — | Aug | — | — | Cold-hardy mustard for fall salads. |
| Mustard Greens | — | Late Apr - May | — | — | Quick fall crop; sweeter after light frost. |
| Napa Cabbage | Apr | — | — | — | Transplant after frost to reduce bolting risk. |
| Onion (Bulb) | Late Feb - Mar | — | — | Sep | Long-day varieties only; start 10-12 weeks before last frost, transplant mid-May. |
| Pac/Corn Salad (Mâche) | — | Aug - Sep | — | Dec - Feb | Extremely cold-hardy; can overwinter under snow. |
| Parsnip | — | Early - Mid May | — | — | Slow germinator; needs full season, sweetens after frost. |
| Pepper (Bell & Hot) | Mar - Early Apr | — | Early - Mid Jun | — | Wait for warm nights (>50°F); black mulch boosts soil heat. |
| Pole Bean | — | Early - Mid Jun | — | — | Sow on warm soil with a trellis. |
| Pole/Runner Bean (Scarlet) | — | Early - Mid Jun | — | — | Handles cool nights better than common beans; ornamental too. |
| Potato | — | — | Early - Mid May | Sep | Plant seed potatoes 2-3 weeks before last frost; hill against late frost. |
| Pumpkin | — | Early Jun | — | — | Pick short-season varieties; start indoors late May for larger types. |
| Radish | — | Late Apr - May | — | — | Fast fall crop; tolerates frost. |
| Rutabaga | — | — | — | Sep - Oct | — |
| Scallion / Green Onion | — | Late Apr - May | — | — | Quick and cold-tolerant; succession-sow. |
| Shallot | — | — | Late Apr - May | — | Plant sets in early spring for summer harvest. |
| Snap / Snow Pea | — | Late Apr - Early May | — | — | Very cold-tolerant; one of the earliest sowings. |
| Spinach | — | Late Jul - Aug | — | — | Fall sowing; very frost-hardy and can overwinter under mulch. |
| Summer Squash | — | Early Jun | — | — | Fast-maturing; sow after frost on warm soil. |
| Swiss Chard | — | Early May | — | — | Sow after worst frosts; productive all season. |
| Tatsoi | — | Aug | — | — | Very cold-tolerant rosette green for fall. |
| Tomatillo | Late Mar - Apr | — | Early - Mid Jun | — | Plant in pairs for fruit set. |
| Tomato | Late Mar - Apr | — | Early - Mid Jun | — | Transplant only after frost risk passes; use Wall O' Water or row cover early. |
| Turnip | — | Late Jul - Aug | — | — | Roots and greens both improve after frost. |
| Winter Squash | — | Early Jun | — | — | Choose early types (e.g. acorn, buttercup); may also start indoors in May to gain time. |
| Zucchini | — | Early Jun | — | — | Direct-sow in warm soil; very productive in short seasons. |
| Plant | Start Indoors | Direct Sow | Transplant | Harvest | Notes |
|---|---|---|---|---|---|
| Basil | Apr | — | Mid Jun | — | Cold-sensitive; do not set out until nights stay above 50°F. |
| Cilantro / Coriander | — | Late Apr - May | — | — | Cool-season; bolts in heat, so sow early and succession. |
| Dill | — | May | — | — | Direct-sow after frost; self-seeds readily. |
| Parsley | Mar - Apr | — | — | — | Slow to germinate; start early or direct-sow late April. |
| Plant | Start Indoors | Direct Sow | Transplant | Harvest | Notes |
|---|---|---|---|---|---|
| Ground Cherry | Late Mar - Apr | — | Early - Mid Jun | — | Sprawling; give room and harvest fallen husks. |
| Muskmelon / Cantaloupe | — | — | Mid Jun | — | Marginal; start indoors May, transplant onto black plastic + tunnel. |
| Watermelon | — | — | Mid Jun | — | Only short-season icebox types under plastic/tunnel will ripen. |
| Plant | Start Indoors | Direct Sow | Transplant | Harvest | Notes |
|---|---|---|---|---|---|
| Borage | — | Early Jun | — | — | Direct-sow; attracts pollinators, self-seeds. |
| Calendula | — | Late Apr - May | — | — | Hardy annual; tolerates cool soil and light frost. |
| Cosmos | — | Early Jun | — | — | Easy from direct seed once frost has passed. |
| Marigold | — | — | Early - Mid Jun | — | Plant after frost; good pest companion. |
| Nasturtium | — | Early Jun | — | — | Direct-sow after frost; edible flowers and leaves. |
| Snapdragon | Mar - Apr | — | — | — | Cold-hardy; transplant early and it shrugs off light frost. |
| Sunflower | — | Late May - Jun | — | — | Direct-sow; choose shorter-season varieties for seed. |
| Sweet Pea | — | Late Apr - May | — | — | Sow early in cool soil; provide support. |
| Zinnia | — | — | Early - Mid Jun | — | Frost-tender; start indoors or transplant after last frost. |
The average first fall frost in zone 3 is Sep 12. To find the last safe planting date for any fall crop, count back from that date by its days to maturity plus a 14-day fall factor — growth slows as days shorten and soil cools. Applied to zone 3's frost date, that gives these plant-by dates:
Plant by Jul 30
30 days to maturity + 14-day fall factor
Plant by Jul 20
40 days to maturity + 14-day fall factor
Plant by Jul 15
45 days to maturity + 14-day fall factor
Plant by Jul 10
50 days to maturity + 14-day fall factor
Count-back dates for every zone are in the fall vegetable planting guide by zone. For what to sow and transplant right now, see what to plant in September.
USDA divides every hardiness zone into two half-zones based on average annual minimum temperature: zone 3a is the cooler half and zone 3b the warmer, 5°F apart. Seed packets and nursery tags usually quote the full zone, but the half-zone is what decides your edge cases — the borderline perennial that survives in 3b and dies in 3a, or the extra week of fall growing 3b buys you.
The dates on this page are zone 3 averages. If you're in zone 3a, treat your last spring frost as about a week later and your first fall frost as about a week earlier than the dates above. In zone 3b, you get roughly a week of grace on each end. Your own microclimate — slope, shelter, pavement, elevation — can swing dates as much as the half-zone does, which is why tracking your garden's actual frost dates beats any table within a season or two.
Track your plants from seed to harvest, get frost alerts, and earn XP for every gardening milestone. Free forever.
Sign Up FreeIn zone 3, spring planting includes Onion (Bulb), Leek, Celery, Celeriac, Pepper (Bell & Hot), Eggplant, Tomato, Tomatillo, and more. See the spring section above for each crop's timing.
The average last spring frost date for USDA zone 3 is May 25. The first fall frost typically arrives around Sep 12, giving a growing season of approximately 105 days.
The average first fall frost in USDA zone 3 arrives around Sep 12. That is an average, not a guarantee — the actual first frost varies by up to 2 weeks either way, so watch your local forecast from a few weeks before that date and have row covers ready for tender crops still in the ground.
In zone 3, start crops like Onion (Bulb) indoors around Late Feb - Mar. Check the seasonal sections above for each crop's indoor-sowing window.
Fall planting in zone 3 includes Garlic, Spinach, Lettuce, Arugula, Mizuna, Tatsoi, Bok Choy / Pak Choi, Mustard Greens, and more.
Zone 3 has an average growing season of 105 days, from the last spring frost around May 25 to the first fall frost around Sep 12.
USDA splits every zone into two half-zones 5°F apart: zone 3a is the cooler half and zone 3b the warmer. The planting dates on this page are zone 3 averages — if you're in 3a, shift spring plantings about a week later and fall plantings about a week earlier; in 3b, shift about a week the other way.
Month-specific guides for zone 3, hand-tuned to current frost dates and crop windows.
Learn more: When to plant vegetables by zone