Frost Dates for Duluth, MN 55802
Duluth has 11 ZIP codes. The Duluth, MN frost page lists all of them with their dates.
Last spring frost May 15 · First fall frost September 30 · 138 frost-free days · USDA Zone 5a
ZIP 55802 has about 2,400 people, one of 11 ZIP codes in Duluth.
Moderate season: 138 frost-free days. Spring frost risk spans April 26–June 8 (43 days). Fall frost risk spans September 17–October 13 (26 days).
Frost probability for 55802
| Frost | 10% | 50% | 90% |
|---|---|---|---|
| Spring (last frost) | June 8 | May 15 | April 26 |
| Fall (first frost) | September 17 | September 30 | October 13 |
Dates come from NOAA 1971–2000 freeze probabilities at DULUTH HARBOR STN (1.8 km away); the 50% date is the median year.
Which crops fit a 138-day season in Duluth
In Duluth (138 frost-free days, a moderate season), 38 of 56 planner crops fit outright, 17 get two plantings, 1 crop is perennial.
| Crop | Start indoors | Plant out / sow | Days you have | Verdict | Last sow date |
|---|---|---|---|---|---|
| Tomato | Apr 10 | May 29–Jun 5 | 96 | fits: 80 days to maturity, 96 available after May 29. | May 31 |
| Pepper | Apr 3 | May 29–Jun 5 | 96 | fits: 75 days to maturity, 96 available after May 29. | Jun 5 |
| Lettuce | Mar 20 | Apr 17–Apr 24 | 173 | two-plantings: Plant Apr 17 and again by Aug 9; both mature before Oct 7. | Aug 9 |
| Carrots | — | Apr 24–May 1 | 180 | fits: 70 days to maturity, 180 available after Apr 24. | Jul 29 |
| Cucumber | Apr 24 | May 29–Jun 5 | 110 | fits: 60 days to maturity, 110 available after May 29. | Jul 4 |
| Beans | — | May 22–Jun 5 | 124 | fits: 60 days to maturity, 124 available after May 22. | Jul 11 |
| Peas | — | Mar 20–May 29 | 201 | fits: 65 days to maturity, 201 available after Mar 20. | Jul 20 |
| Zucchini | May 1 | May 29–Jun 5 | 110 | fits: 55 days to maturity, 110 available after May 29. | Jul 9 |
| Onion | Feb 20 | Apr 17–May 1 | 173 | fits: 100 days to maturity, 173 available after Apr 17. | — |
| Spinach | — | Mar 20–May 8 | 215 | two-plantings: Plant Mar 20 and again by Aug 28; both mature before Oct 21. | Aug 28 |
| Kale | Mar 6 | Apr 17–May 1 | 187 | two-plantings: Plant Apr 17 and again by Aug 13; both mature before Oct 21. | Aug 13 |
| Broccoli | Mar 20 | Apr 17–May 1 | 173 | fits: 80 days to maturity, 173 available after Apr 17. | Jul 5 |
| Cabbage | Mar 20 | Apr 17–May 1 | 187 | fits: 70 days to maturity, 187 available after Apr 17. | Jul 29 |
| Radish | — | Mar 20–Jun 12 | 201 | two-plantings: Plant Mar 20 and again by Aug 29; both mature before Oct 7. | Aug 29 |
| Beets | — | Mar 20–Jun 12 | 201 | two-plantings: Plant Mar 20 and again by Jul 30; both mature before Oct 7. | Jul 30 |
| Potatoes | — | May 1–May 8 | 159 | fits: 90 days to maturity, 159 available after May 1. | — |
| Garlic | — | Sep 30 | 243 | overwinter: Plant Sep 30 to Oct 21; harvest the following summer. | Oct 21 |
| Strawberry | — | Apr 10–Jun 5 | 194 | perennial: A perennial: plant Apr 10; it fruits from the following year and keeps producing for several years. | — |
| Corn | Apr 17 | May 22–May 29 | 110 | fits: 75 days to maturity, 110 available after May 22. | Jun 12 |
| Pumpkin | May 1 | May 29–May 29 | 103 | fits: 100 days to maturity, 103 available after May 29. | — |
| Cauliflower | Apr 3 | May 8–May 22 | 152 | fits: 75 days to maturity, 152 available after May 8. | Jul 10 |
| Swiss Chard | Mar 20 | May 1–May 1 | 159 | two-plantings: Plant May 1 and again by Jul 30; both mature before Oct 7. | Jul 30 |
| Arugula | — | Mar 20–Jun 12 | 215 | two-plantings: Plant Mar 20 and again by Aug 28; both mature before Oct 21. | Aug 28 |
| Brussel Sprouts | Mar 20 | Apr 17–May 1 | 187 | fits: 100 days to maturity, 187 available after Apr 17. | Jun 29 |
| Butternut Squash | May 1 | May 29–Jun 5 | 103 | fits: 100 days to maturity, 103 available after May 29. | — |
| Eggplant | Mar 27 | May 29–Jun 5 | 96 | fits: 70 days to maturity, 96 available after May 29. | Jun 10 |
| Okra | Apr 17 | May 22–May 29 | 117 | fits: 55 days to maturity, 117 available after May 22. | Jul 9 |
| Basil | Apr 10 | Jun 5–Jun 5 | 103 | fits: 60 days to maturity, 103 available after Jun 5. | Jul 4 |
| Cilantro | — | Apr 17–May 8 | 173 | two-plantings: Plant Apr 17 and again by Aug 4; both mature before Oct 7. | Aug 4 |
| Parsley | Mar 6 | May 22–May 29 | 138 | fits: 70 days to maturity, 138 available after May 22. | Jul 15 |
| Celery | Mar 6 | May 22–Jun 5 | 138 | fits: 120 days to maturity, 138 available after May 22. | May 26 |
| Scallions | Mar 6 | Apr 17–May 1 | 187 | two-plantings: Plant Apr 17 and again by Aug 8; both mature before Oct 21. | Aug 8 |
| Turnip | — | Apr 17–May 1 | 187 | two-plantings: Plant Apr 17 and again by Aug 18; both mature before Oct 21. | Aug 18 |
| Kohlrabi | — | Apr 3–Apr 17 | 201 | two-plantings: Plant Apr 3 and again by Aug 13; both mature before Oct 21. | Aug 13 |
| Bok Choy | Apr 17 | May 8–May 15 | 152 | two-plantings: Plant May 8 and again by Aug 9; both mature before Oct 7. | Aug 9 |
| Collards | Mar 6 | Apr 17–May 1 | 187 | two-plantings: Plant Apr 17 and again by Aug 8; both mature before Oct 21. | Aug 8 |
| Cantaloupe | May 1 | May 29–Jun 5 | 96 | fits: 85 days to maturity, 96 available after May 29. | — |
| Chives | Feb 20 | May 22–May 29 | 152 | fits: 90 days to maturity, 152 available after May 22. | — |
| Dill | — | Mar 20–Jun 12 | 201 | two-plantings: Plant Mar 20 and again by Jul 30; both mature before Oct 7. | Jul 30 |
| Oregano | Mar 6 | May 22–May 29 | 152 | fits: 80 days to maturity, 152 available after May 22. | — |
| Rosemary | Feb 20 | May 22–May 29 | 138 | fits: 80 days to maturity, 138 available after May 22. | — |
| Sage | Mar 20 | May 22–May 29 | 152 | fits: 75 days to maturity, 152 available after May 22. | — |
| Thyme | Mar 6 | May 22–May 29 | 152 | fits: 90 days to maturity, 152 available after May 22. | — |
| Calendula | Apr 3 | May 1–May 15 | 159 | two-plantings: Plant May 1 and again by Aug 4; both mature before Oct 7. | Aug 4 |
| Cosmos | Apr 17 | May 15–May 29 | 124 | fits: 60 days to maturity, 124 available after May 15. | Jul 4 |
| Lavender | Feb 20 | May 15–May 29 | 159 | fits: 90 days to maturity, 159 available after May 15. | — |
| Marigolds | Apr 3 | May 15–May 22 | 124 | two-plantings: Plant May 15 and again by Jul 14; both mature before Sep 16. | Jul 14 |
| Melons | May 1 | May 29–Jun 5 | 96 | fits: 85 days to maturity, 96 available after May 29. | — |
| Mint | — | May 15–May 29 | 159 | fits: 90 days to maturity, 159 available after May 15. | — |
| Nasturtiums | Apr 17 | May 15–May 22 | 124 | two-plantings: Plant May 15 and again by Jul 9; both mature before Sep 16. | Jul 9 |
| Pole Beans | — | May 22–Jun 5 | 117 | fits: 65 days to maturity, 117 available after May 22. | Jun 29 |
| Spaghetti Squash | May 1 | May 29–Jun 5 | 103 | fits: 90 days to maturity, 103 available after May 29. | — |
| Sunflowers | — | May 15–May 29 | 124 | fits: 70 days to maturity, 124 available after May 15. | Jun 24 |
| Tomatillos | Mar 20 | May 22–May 29 | 103 | fits: 75 days to maturity, 103 available after May 22. | Jun 5 |
| Watermelon | May 1 | May 22–May 29 | 103 | fits: 80 days to maturity, 103 available after May 22. | May 31 |
| Yellow Squash | May 1 | May 29–Jun 5 | 110 | fits: 55 days to maturity, 110 available after May 29. | Jul 9 |
| Zinnias | Apr 17 | May 15–May 29 | 124 | fits: 60 days to maturity, 124 available after May 15. | Jul 4 |
Month by month in Duluth
| Month | What to do |
|---|---|
| January | Plan your garden layout and order seeds. Research varieties suited to your frost dates. |
| February | Start indoors: Chives (Feb 20), Lavender (Feb 20), Onion (Feb 20), Rosemary (Feb 20). |
| March | Start indoors: Celery (Mar 6), Collards (Mar 6), Kale (Mar 6), Oregano (Mar 6), Parsley (Mar 6), Scallions (Mar 6), +9 more. Direct sow from: Arugula (Mar 20), Beets (Mar 20), Dill (Mar 20), Peas (Mar 20), Radish (Mar 20), Spinach (Mar 20). |
| April | Start indoors: Calendula (Apr 3), Cauliflower (Apr 3), Marigolds (Apr 3), Pepper (Apr 3), Basil (Apr 10), Tomato (Apr 10), +7 more. Direct sow from: Kohlrabi (Apr 3), Cilantro (Apr 17), Turnip (Apr 17), Carrots (Apr 24). Transplant from: Broccoli (Apr 17), Brussel Sprouts (Apr 17), Cabbage (Apr 17), Collards (Apr 17), Kale (Apr 17), Lettuce (Apr 17), +2 more. Plant: Strawberry (Apr 10). |
| May | Start indoors: Butternut Squash (May 1), Cantaloupe (May 1), Melons (May 1), Pumpkin (May 1), Spaghetti Squash (May 1), Watermelon (May 1), +2 more. Direct sow from: Potatoes (May 1), Sunflowers (May 15), Beans (May 22), Pole Beans (May 22). Transplant from: Calendula (May 1), Swiss Chard (May 1), Bok Choy (May 8), Cauliflower (May 8), Cosmos (May 15), Lavender (May 15), +26 more. Last frost around May 15. Last sowing dates: Celery (May 26), Tomato (May 31), Watermelon (May 31). |
| June | Transplant from: Basil (Jun 5). Last sowing dates: Pepper (Jun 5), Tomatillos (Jun 5), Eggplant (Jun 10), Corn (Jun 12), Sunflowers (Jun 24), Brussel Sprouts (Jun 29), +1 more. |
| July | Last sowing dates: Basil (Jul 4), Cosmos (Jul 4), Cucumber (Jul 4), Zinnias (Jul 4), Broccoli (Jul 5), Nasturtiums (Jul 9), +13 more. |
| August | Last sowing dates: Calendula (Aug 4), Cilantro (Aug 4), Collards (Aug 8), Scallions (Aug 8), Bok Choy (Aug 9), Lettuce (Aug 9), +6 more. |
| September | Direct sow from: Garlic (Sep 30). First frost around September 30. |
| October | Last sowing dates: Garlic (Oct 21). |
| November | Clean up spent plants. Add compost to beds. Rest, review, and plan next year's garden. |
| December | Clean up spent plants. Add compost to beds. Rest, review, and plan next year's garden. |
Frequently Asked Questions
What is the last frost date for Duluth, MN (ZIP 55802)?
The median last spring frost date for Duluth, MN (ZIP code 55802) is around May 15. This is the 50th-percentile date — meaning half of all years see frost end before this date. Use the 10% and 90% dates to understand the full range of risk in your area. One year in ten frost ends before April 26; one in ten it runs past June 8.
What is the first fall frost date in Duluth, MN?
The median first fall frost date for Duluth, MN is around September 30. Plan to harvest or protect frost-sensitive crops like tomatoes and peppers at least a week before this date to avoid losses. The first frost arrives around September 17 in the earliest one-in-ten years, so cover tomatoes and peppers from then.
How long is the growing season in Duluth, MN?
The frost-free growing season in Duluth is about 138 days. This window — from your last spring frost to your first fall frost — is when warm-season vegetables thrive. Cold-hardy crops like kale, spinach, and peas can extend your season by weeks on either side. In Duluth (138 frost-free days, a moderate season), 38 of 56 planner crops fit outright, 17 get two plantings, 1 crop is perennial.
What USDA hardiness zone is Duluth, MN?
Duluth, MN is in USDA hardiness zone 5a (2023 USDA Plant Hardiness Zone Map). Zones come from the average coldest winter temperature, so they tell you which perennials survive the winter; the frost dates on this page tell you when to plant.
When should I start tomatoes indoors in Duluth, MN?
Start tomatoes indoors Apr 10 and plant out May 29 in Duluth. The planner uses the local median last frost and this crop's indoor-start and transplant offsets.
How many plantings of lettuce fit in Duluth?
Two: plant Apr 17 and again by Aug 9; both mature before Oct 7.
When do I plant garlic in Duluth?
Sep 30 to Oct 21; it overwinters and is ready the following summer.
Nearby and related
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