Frost Dates & Planting Calendar for Ankeny, IA
Plan your garden around Ankeny, IA's typical frost-free growing season, using NOAA climate normals and a 42-crop planting calendar built for this location.
Last Spring Frost
April 23
Safe May 6
Typical Apr 23
Risky Apr 8
First Fall Frost
October 15
Safe Sep 30
Typical Oct 15
Risky Oct 28
Growing Season
173 days
Typical last frost to typical first frost.
USDA Hardiness Zone
Zone 5b
A classic four-season climate with cold winters and a solid summer growing season.
Data: NOAA station ANKENY, IA US, 3.7 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 26 – Mar 12 | — | Apr 30 – May 7 | — | 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 12 – Feb 26 | — | Apr 30 – May 14 | — | 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 12 – Feb 26 | — | May 7 – May 14 | — | 65–85 days | Warm-season crop, similar timing to pepper; needs consistently warm soil (65F+) to transplant. |
| Cucumber | Mar 26 – Apr 2 | Apr 30 – May 7 | Apr 30 – May 7 | — | 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 2 – Apr 9 | Apr 30 – May 14 | Apr 30 – May 7 | — | 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 26 – Apr 2 | Apr 30 – May 14 | Apr 30 – May 7 | — | 80–110 days | Long season; direct sow after soil warms, or start indoors 3-4 weeks before last frost in short-season climates. |
| Pumpkin | — | Apr 30 – May 14 | — | — | 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 26 – Apr 2 | — | May 7 – May 14 | — | 70–90 days | Needs warm soil (65F+); start indoors 3-4 weeks before last frost, transplant 2-3 weeks after last frost. |
| Cantaloupe | Mar 26 – Apr 2 | — | May 7 – May 14 | — | 70–90 days | Same warm-soil requirements as watermelon; avoid disturbing roots when transplanting. |
| Corn | — | Apr 23 – May 7 | — | — | 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 23 – May 7 | — | — | 50–65 days | Direct sow at last frost to 2 weeks after, once soil has warmed; frost-tender, do not rush. |
| Pea | — | Mar 12 – Mar 26 | — | — | 55–70 days | Cold-hardy; direct sow 4-6 weeks before last frost as soon as soil can be worked. |
| Lettuce | — | Mar 26 – Apr 9 | — | Aug 20 – Sep 3 | 45–60 days | Cold-hardy; direct sow 2-4 weeks before last frost. Also transplantable from indoor starts. |
| Spinach | — | Mar 12 – Mar 26 | — | Aug 20 – Sep 3 | 40–50 days | Very cold-hardy; direct sow 4-6 weeks before last frost as soon as soil can be worked. |
| Kale | — | Mar 26 – Apr 9 | — | Aug 6 – Aug 20 | 50–65 days | Cold-hardy; direct sow 2-4 weeks before last frost or start indoors for earlier transplants. |
| Arugula | — | Mar 26 – Apr 9 | — | Sep 3 – Sep 10 | 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 2 – Apr 16 | — | — | 50–60 days | Fairly cold-hardy; direct sow 1-3 weeks before last frost. Tolerates light frost in fall too. |
| Broccoli | Mar 5 – Mar 19 | — | Apr 2 – Apr 9 | Aug 13 – Aug 20 | 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 5 – Mar 19 | — | Apr 9 – Apr 16 | Aug 6 – Aug 13 | 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 5 – Mar 19 | — | Mar 26 – Apr 9 | Aug 6 – Aug 20 | 60–100 days | Cold-hardy; start indoors 5-7 weeks before last frost, transplant 2-4 weeks before last frost. |
| Brussels Sprouts | Mar 5 – Mar 19 | — | Apr 2 – Apr 16 | — | 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 26 – Apr 9 | — | Jul 23 – Aug 6 | 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 26 – Apr 9 | — | Aug 6 – Aug 20 | 50–65 days | Direct sow 2-4 weeks before last frost; tolerates light frost. |
| Radish | — | Mar 19 – Apr 2 | — | Sep 3 – Sep 17 | 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 26 – Apr 9 | — | Aug 6 – Aug 20 | 40–60 days | Cold-hardy; direct sow 2-4 weeks before last frost. |
| Onion | Feb 12 – Feb 26 | — | Mar 26 – Apr 9 | — | 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 17 – Oct 1 | 240–270 days | Fall-planted crop only; not planted in spring in most climates. |
| Potato | — | Mar 26 – Apr 9 | — | — | 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 7 – May 21 | — | 90–120 days | Set out slips 2-4 weeks after last frost once soil is thoroughly warm (65F+); very frost/cold sensitive. |
| Asparagus | — | — | Mar 26 – Apr 9 | — | 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 12 – Mar 19 | — | Apr 30 – May 7 | — | 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 2 – Apr 16 | — | Aug 20 – Sep 3 | 45–70 days | Cool-season, bolts in heat; direct sow 1-3 weeks before last frost, succession sow through spring. |
| Parsley | Feb 26 – Mar 12 | — | Apr 9 – Apr 16 | — | 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 2 – Apr 16 | — | — | 40–60 days | Taprooted, does not transplant well; direct sow 1-3 weeks before last frost, succession sow through summer. |
| Oregano | Feb 26 – Mar 12 | — | Apr 23 – Apr 30 | — | 80–90 days | Perennial herb; start indoors 6-8 weeks before last frost, transplant around/just after last frost date. |
| Thyme | Feb 26 – Mar 12 | — | Apr 23 – Apr 30 | — | 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 | — | Apr 30 – May 14 | — | — | 70–100 days | Direct sow 1-3 weeks after last frost once soil has warmed; taprooted, resents transplanting. |
| Zinnia | Mar 26 – Apr 2 | Apr 30 – May 14 | Apr 30 – May 7 | — | 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 12 – Mar 26 | — | Apr 30 – May 7 | — | 45–60 days | Frost-tender; start indoors 4-6 weeks before last frost, transplant after all frost danger has passed. |
| Cosmos | Mar 26 – Apr 2 | Apr 30 – May 14 | Apr 30 – May 7 | — | 60–90 days | Easy from direct seed 1-3 weeks after last frost; can also start indoors 3-4 weeks early. |
| Nasturtium | — | Apr 30 – May 14 | — | — | 50–65 days | Frost-tender, resents root disturbance; direct sow 1-3 weeks after last frost once soil has warmed. |
| Dahlia | — | — | Apr 30 – May 14 | — | 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 Ankeny, IA?
Based on 1991–2020 NOAA climate normals for the ANKENY, IA US station, the last spring frost in Ankeny typically falls around April 23. A cautious gardener might wait until May 6 (only a 10% chance of a later frost), while April 8 marks an earlier, higher-risk planting date.
When is the first frost in Ankeny, IA in fall?
The first fall frost in Ankeny typically arrives around October 15. To stay safe, assume frost could start as early as September 30; in milder years it can hold off until October 28.
How long is the growing season in Ankeny, IA?
Ankeny's average frost-free growing season is about 173 days, running from the typical last spring frost (April 23) to the typical first fall frost (October 15).
What USDA hardiness zone is Ankeny, IA in?
Ankeny, IA is in USDA plant hardiness zone 5b, per the USDA's 2023 Plant Hardiness Zone Map. A classic four-season climate with cold winters and a solid summer growing season.