Frost Dates & Planting Calendar for Mendota Heights, MN
Plan your garden around Mendota Heights, MN's typical frost-free growing season, using NOAA climate normals and a 42-crop planting calendar built for this location.
Last Spring Frost
April 25
Safe May 9
Typical Apr 25
Risky Apr 9
First Fall Frost
October 12
Safe Oct 1
Typical Oct 12
Risky Oct 25
Growing Season
169 days
Typical last frost to typical first frost.
USDA Hardiness Zone
Zone 5a
A classic four-season climate with cold winters and a solid summer growing season.
Data: NOAA station ST PAUL 3SW, MN US, 5.4 km away.
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days until the typical last spring frost
Monthly Temperatures
Avg. high
Avg. temp
Avg. low
Planting Calendar
| Crop | Start indoors | Direct sow | Transplant | Fall planting | Maturity | Notes |
|---|---|---|---|---|---|---|
| Tomato | Feb 28 – Mar 14 | — | May 2 – May 9 | — | 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 14 – Feb 28 | — | May 2 – May 16 | — | 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 14 – Feb 28 | — | May 9 – May 16 | — | 65–85 days | Warm-season crop, similar timing to pepper; needs consistently warm soil (65F+) to transplant. |
| Cucumber | Mar 28 – Apr 4 | May 2 – May 9 | May 2 – May 9 | — | 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 4 – Apr 11 | May 2 – May 16 | May 2 – May 9 | — | 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 28 – Apr 4 | May 2 – May 16 | May 2 – May 9 | — | 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 2 – May 16 | — | — | 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 28 – Apr 4 | — | May 9 – May 16 | — | 70–90 days | Needs warm soil (65F+); start indoors 3-4 weeks before last frost, transplant 2-3 weeks after last frost. |
| Cantaloupe | Mar 28 – Apr 4 | — | May 9 – May 16 | — | 70–90 days | Same warm-soil requirements as watermelon; avoid disturbing roots when transplanting. |
| Corn | — | Apr 25 – May 9 | — | — | 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 25 – May 9 | — | — | 50–65 days | Direct sow at last frost to 2 weeks after, once soil has warmed; frost-tender, do not rush. |
| Pea | — | Mar 14 – Mar 28 | — | — | 55–70 days | Cold-hardy; direct sow 4-6 weeks before last frost as soon as soil can be worked. |
| Lettuce | — | Mar 28 – Apr 11 | — | Aug 17 – Aug 31 | 45–60 days | Cold-hardy; direct sow 2-4 weeks before last frost. Also transplantable from indoor starts. |
| Spinach | — | Mar 14 – Mar 28 | — | Aug 17 – Aug 31 | 40–50 days | Very cold-hardy; direct sow 4-6 weeks before last frost as soon as soil can be worked. |
| Kale | — | Mar 28 – Apr 11 | — | Aug 3 – Aug 17 | 50–65 days | Cold-hardy; direct sow 2-4 weeks before last frost or start indoors for earlier transplants. |
| Arugula | — | Mar 28 – Apr 11 | — | Aug 31 – Sep 7 | 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 4 – Apr 18 | — | — | 50–60 days | Fairly cold-hardy; direct sow 1-3 weeks before last frost. Tolerates light frost in fall too. |
| Broccoli | Mar 7 – Mar 21 | — | Apr 4 – Apr 11 | Aug 10 – Aug 17 | 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 7 – Mar 21 | — | Apr 11 – Apr 18 | Aug 3 – Aug 10 | 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 7 – Mar 21 | — | Mar 28 – Apr 11 | Aug 3 – Aug 17 | 60–100 days | Cold-hardy; start indoors 5-7 weeks before last frost, transplant 2-4 weeks before last frost. |
| Brussels Sprouts | Mar 7 – Mar 21 | — | Apr 4 – Apr 18 | — | 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 28 – Apr 11 | — | Jul 20 – Aug 3 | 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 28 – Apr 11 | — | Aug 3 – Aug 17 | 50–65 days | Direct sow 2-4 weeks before last frost; tolerates light frost. |
| Radish | — | Mar 21 – Apr 4 | — | Aug 31 – Sep 14 | 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 28 – Apr 11 | — | Aug 3 – Aug 17 | 40–60 days | Cold-hardy; direct sow 2-4 weeks before last frost. |
| Onion | Feb 14 – Feb 28 | — | Mar 28 – Apr 11 | — | 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 14 – Sep 28 | 240–270 days | Fall-planted crop only; not planted in spring in most climates. |
| Potato | — | Mar 28 – Apr 11 | — | — | 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 9 – May 23 | — | 90–120 days | Set out slips 2-4 weeks after last frost once soil is thoroughly warm (65F+); very frost/cold sensitive. |
| Asparagus | — | — | Mar 28 – Apr 11 | — | 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. |
| Crop | Start indoors | Direct sow | Transplant | Fall planting | Maturity | Notes |
|---|---|---|---|---|---|---|
| Basil | Mar 14 – Mar 21 | — | May 2 – May 9 | — | 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 4 – Apr 18 | — | Aug 17 – Aug 31 | 45–70 days | Cool-season, bolts in heat; direct sow 1-3 weeks before last frost, succession sow through spring. |
| Parsley | Feb 28 – Mar 14 | — | Apr 11 – Apr 18 | — | 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 4 – Apr 18 | — | — | 40–60 days | Taprooted, does not transplant well; direct sow 1-3 weeks before last frost, succession sow through summer. |
| Oregano | Feb 28 – Mar 14 | — | Apr 25 – May 2 | — | 80–90 days | Perennial herb; start indoors 6-8 weeks before last frost, transplant around/just after last frost date. |
| Thyme | Feb 28 – Mar 14 | — | Apr 25 – May 2 | — | 85–95 days | Perennial herb, slow from seed; start indoors 6-8 weeks before last frost, transplant around/after last frost. |
| Crop | Start indoors | Direct sow | Transplant | Fall planting | Maturity | Notes |
|---|---|---|---|---|---|---|
| Sunflower | — | May 2 – May 16 | — | — | 70–100 days | Direct sow 1-3 weeks after last frost once soil has warmed; taprooted, resents transplanting. |
| Zinnia | Mar 28 – Apr 4 | May 2 – May 16 | May 2 – May 9 | — | 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 14 – Mar 28 | — | May 2 – May 9 | — | 45–60 days | Frost-tender; start indoors 4-6 weeks before last frost, transplant after all frost danger has passed. |
| Cosmos | Mar 28 – Apr 4 | May 2 – May 16 | May 2 – May 9 | — | 60–90 days | Easy from direct seed 1-3 weeks after last frost; can also start indoors 3-4 weeks early. |
| Nasturtium | — | May 2 – May 16 | — | — | 50–65 days | Frost-tender, resents root disturbance; direct sow 1-3 weeks after last frost once soil has warmed. |
| Dahlia | — | — | May 2 – May 16 | — | 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.
Frequently Asked Questions
When is the last frost in Mendota Heights, MN?
Based on 1991–2020 NOAA climate normals for the ST PAUL 3SW, MN US station, the last spring frost in Mendota Heights typically falls around April 25. A cautious gardener might wait until May 9 (only a 10% chance of a later frost), while April 9 marks an earlier, higher-risk planting date.
When is the first frost in Mendota Heights, MN in fall?
The first fall frost in Mendota Heights typically arrives around October 12. To stay safe, assume frost could start as early as October 1; in milder years it can hold off until October 25.
How long is the growing season in Mendota Heights, MN?
Mendota Heights's average frost-free growing season is about 169 days, running from the typical last spring frost (April 25) to the typical first fall frost (October 12).
What USDA hardiness zone is Mendota Heights, MN in?
Mendota Heights, MN is in USDA plant hardiness zone 5a, per the USDA's 2023 Plant Hardiness Zone Map. A classic four-season climate with cold winters and a solid summer growing season.