Fall in zone 5bPhoto: Dietmar Rabich, CC BY-SA 4.0, via Wikimedia Commons
Frost dates for ZIP 50072 (Earlham, IA)
Average last spring and first fall frost dates with 10%, 50% and 90% odds, from NOAA's 1991–2020 climate normals for the nearest weather station, Winterset 1S, IA (12 miles away).
- Average last spring frostApr 3050% chance of a 32°F freeze after this date
- Average first fall frostOct 350% chance of a 32°F freeze by this date
- Growing season (frost-free)157 daysmedian, 32°F threshold
- USDA hardiness zone5b-15 to -10°F avg. coldest night
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This week in your yard
As of Oct 18, 2026, from your frost dates, zone and soil temperature. Lawn timing · Vegetables · Pruning · Plants
Soil temperature now
2-inch depth
55°F 55°F or warmer
24-hour average · latest 55°F, as of Oct 18, 2:00 AM CDT
Estimate Not a measurement at this ZIP: distance-weighted average of Ames (43 mi), Des Moines 17 E (44 mi).
4-inch depth
57°F 55°F or warmer
24-hour average · latest 56°F, as of Oct 18, 2:00 AM CDT
Estimate Not a measurement at this ZIP: distance-weighted average of Ames (43 mi), Des Moines 17 E (44 mi).
Fall: Texas A&M AgriLife times fall pre-emergent (for winter weeds such as annual bluegrass) to soil cooling to about 70°F for several days. The 50–55°F band is the spring trigger. Always read and follow the product label.
7-day forecast and frost risk
The latest National Weather Service 7-day forecast and any Frost Advisory or Freeze Warning for 50072 load here. You can also open the NWS forecast for this ZIP.
Pre-emergent
Soil is 57°F at 4 inches (estimated soil temperature, not a station reading). Fall pre-emergent (annual bluegrass, winter weeds): window open as soil cools through the 70s and 60s.
Fertilizer window
Lawn region: North (cool-season). Timing only; always follow the product label.
- Kentucky bluegrass (cool-season): Early fall: Around Labor Day (late August–September); Late fall: Late October–November, before the ground freezes; Late spring: Optional around Memorial Day. Avoid: Early-spring and midsummer feeding (pushes top growth, favors crabgrass).
Plant now
No vegetable planting windows are open this week.
Prune now
No frost-timed pruning windows are open this week.
Spring-flowering shrubs are pruned right after their flowers fade, not by date. See the pruning guide.
Last spring frost odds
| Chance of a 32°F freeze after this date | Date |
|---|---|
| 90% (early: most years still freeze after this) | Apr 17 |
| 50% (the "average" last frost) | Apr 30 |
| 10% (cautious: only 1 year in 10 freezes later) | May 11 |
Most gardeners plant frost-tender crops (tomatoes, peppers, basil) after the 50% date, and closer to the 10% date for less risk.
First fall frost odds
| Chance the first 32°F freeze has happened by this date | Date |
|---|---|
| 10% (early: 1 year in 10 freezes this soon) | Sep 20 |
| 50% (the "average" first frost) | Oct 3 |
| 90% (late: most years have frozen by now) | Oct 20 |
Light frost, freeze and hard freeze
| Threshold | Last spring (50%) | First fall (50%) |
|---|---|---|
| 36°F (light frost possible on clear, calm nights) | May 9 | Sep 26 |
| 32°F (freeze) | Apr 30 | Oct 3 |
| 28°F (hard freeze) | Apr 20 | Oct 15 |
n/a means NOAA did not publish a date at that threshold for this station (usually because it rarely gets that cold).
Vegetable planting calendar for 50072
Dates count from your average last spring frost (Apr 30) and first fall frost (Oct 3). Half of years have a frost after the spring date, so give tender crops (tomatoes, peppers, squash) some slack.
| Crop | Start indoors | Spring planting | Fall planting |
|---|---|---|---|
| Tomato | Mar 5–19 | May 7–21 (transplant) | – |
| Pepper (sweet and hot) | Feb 19–Mar 5 | May 14–28 (transplant) | – |
| Eggplant | Feb 19–Mar 5 | May 14–28 (transplant) | – |
| Tomatillo | Mar 5–19 | May 7–21 (transplant) | – |
| Lettuce | Mar 5–19 | Apr 9–30 (transplant) Apr 2–May 14 (sow outdoors) | Aug 8–29 (transplant) Jul 25–Aug 22 (sowing) |
| Spinach | – | Mar 19–Apr 9 (sow outdoors) | Aug 8–29 (sowing) |
| Kale | Mar 5–19 | Apr 2–16 (transplant) Apr 2–16 (sow outdoors) | Jul 11–Aug 8 (transplant) Jun 27–Jul 25 (sowing) |
| Collards | Mar 5–19 | Apr 2–30 (transplant) Apr 2–30 (sow outdoors) | Jul 11–Aug 8 (transplant) Jun 27–Jul 25 (sowing) |
| Broccoli | Feb 19–Mar 5 | Apr 2–16 (transplant) | Jun 27–Jul 25 (transplant) |
| Cabbage | Feb 19–Mar 5 | Apr 2–16 (transplant) | Jun 27–Jul 25 (transplant) |
| Cauliflower | Feb 19–Mar 5 | Apr 16–30 (transplant) | Jun 27–Jul 25 (transplant) |
| Brussels sprouts | Feb 5–19 | Apr 2–16 (transplant) | Jun 13–Jul 4 (transplant) |
| Kohlrabi | Mar 5–19 | Apr 2–16 (transplant) Apr 2–16 (sow outdoors) | Jul 25–Aug 8 (sowing) |
| Bok choy / Asian greens | – | Apr 2–16 (sow outdoors) | Aug 8–22 (sowing) |
| Arugula | – | Apr 2–30 (sow outdoors) | Aug 8–Sep 5 (sowing) |
| Mustard greens | – | Apr 2–23 (sow outdoors) | Aug 8–22 (sowing) |
| Swiss chard | Mar 19–Apr 2 | Apr 16–May 7 (transplant) Apr 16–May 14 (sow outdoors) | Jul 25–Aug 8 (sowing) |
| Beet | – | Apr 2–30 (sow outdoors) | Jul 25–Aug 8 (sowing) |
| Carrot | – | Apr 9–May 7 (sow outdoors) | Jul 11–25 (sowing) |
| Radish | – | Mar 26–May 7 (sow outdoors) | Aug 22–Sep 5 (sowing) |
| Turnip | – | Apr 2–23 (sow outdoors) | Jul 25–Aug 8 (sowing) |
| Parsnip | – | Apr 9–30 (sow outdoors) | – |
| Pea (garden, snap, snow) | – | Mar 5–Apr 2 (sow outdoors) | Jul 11–25 (sowing) |
| Onion (bulbing) | Feb 5–19 | Mar 19–Apr 2 (transplant) | – |
| Green onion / scallion | – | Mar 19–Apr 16 (sow outdoors) | Jul 25–Aug 8 (sowing) |
| Leek | Feb 5–19 | Apr 2–16 (transplant) | – |
| Garlic | – | – | Aug 22–Sep 19 (sowing) |
| Shallot | – | Mar 19–Apr 2 (transplant) | Aug 22–Sep 19 (sowing) |
| Potato | – | Apr 2–16 (transplant) | Jun 13–27 (transplant) |
| Sweet potato | – | May 21–Jun 4 (transplant) | – |
| Sweet corn | – | May 7–21 (sow outdoors) | – |
| Bean, bush (snap) | – | May 7–21 (sow outdoors) | – |
| Bean, pole | – | May 7–21 (sow outdoors) | – |
| Lima bean | – | May 14–28 (sow outdoors) | – |
| Southern pea (cowpea, black-eyed pea) | – | May 21–Jun 11 (sow outdoors) | – |
| Cucumber | Apr 2–9 | May 7–21 (transplant) May 7–21 (sow outdoors) | – |
| Summer squash / zucchini | Apr 2–9 | May 7–21 (transplant) May 7–21 (sow outdoors) | – |
| Winter squash | Apr 2–9 | May 7–21 (transplant) May 7–21 (sow outdoors) | – |
| Pumpkin | – | May 7–21 (sow outdoors) | – |
| Watermelon | Apr 2–9 | May 14–28 (transplant) May 14–28 (sow outdoors) | – |
| Cantaloupe / muskmelon | Apr 2–9 | May 14–28 (transplant) May 14–28 (sow outdoors) | – |
| Okra | Mar 19–Apr 2 | May 14–28 (transplant) May 14–28 (sow outdoors) | – |
| Celery | Feb 5–19 | May 7–14 (transplant) | – |
| Basil | Mar 19–Apr 2 | May 7–21 (transplant) May 7–21 (sow outdoors) | – |
| Cilantro | – | Apr 16–May 14 (sow outdoors) | Aug 8–22 (sowing) |
| Parsley | Feb 19–Mar 5 | Apr 16–30 (transplant) Apr 9–30 (sow outdoors) | – |
| Dill | – | Apr 30–May 14 (sow outdoors) | Aug 8–22 (sowing) |
| Sunflower | – | Apr 30–May 14 (sow outdoors) | – |
| Asparagus (crowns) | – | Apr 2–16 (transplant) | – |
| Rhubarb (crowns) | – | Apr 2–16 (transplant) | – |
| Strawberry (plants) | – | Apr 2–16 (transplant) | Jul 25–Aug 22 (transplant) |
Typical ranges from university extension planting calendars, adjusted to your frost dates. Probabilities, not guarantees. Fall windows that would overlap spring planting are left out, as are fall crops of frost-tender plants where the frost-free season is under 210 days.
Where these numbers come from
Station: Winterset 1S, IA (NOAA GHCN-Daily ID USC00139132), elevation 1,100 ft, 12.1 miles from the ZIP's center point. NOAA completeness flag: R (representative, 10+ years).
Nearby stations
| Station | Distance | Last frost (50%) | First frost (50%) |
|---|---|---|---|
| Greenfield, IA | 21 mi | Apr 25 | Oct 12 |
| Guthrie Ctr, IA | 24 mi | May 2 | Oct 3 |
| Des Moines Intl AP, IA | 25 mi | Apr 18 | Oct 20 |
The average last-frost dates of these stations span 15 days, a rough guide to local variation. See data sources & methods.
Frost questions for 50072
When is the last frost in 50072?
The average (50% chance) last spring freeze of 32°F for ZIP 50072 is April 30. For a more cautious planting date, use May 11, when only 1 year in 10 still sees a later freeze.
When is the first frost in 50072?
The average first fall freeze is October 3. In 1 year in 10 it comes by September 20.
What hardiness zone is 50072?
ZIP 50072 is in USDA zone 5b (-15 to -10°F average coldest winter night), per the 2023 USDA Plant Hardiness Zone Map ZIP listing.
What is the soil temperature in 50072 right now?
This page shows the latest 2-inch and 4-inch soil temperature from the nearest public soil station (USDA SCAN, NOAA USCRN or TexMesonet), or a labeled estimate when no station is close, against the 50–55°F spring pre-emergent band.
Nearby ZIP codes
50069 De Soto 50070 Dexter 50261 Van Meter 50003 Adel 50273 Winterset 50233 Redfield 50250 Stuart 50038
Other ZIP codes in Madison County
50033 50061 50070 50149 50155 50218 50222 50240 50257 50261 50273 All Madison County frost dates · Iowa frost dates
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Weekly yard timing, plus frost and soil-temperature alerts for your ZIP code.
- Freeze alerts
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Free. One weekly email plus alerts when your ZIP has a frost or a soil-temperature change worth acting on. After you submit, Kit (our email provider) sends a confirmation email: check your email and click the link to confirm. You aren't subscribed until you do. We collect only your email address and ZIP, sent to Kit to deliver The Dial. Unsubscribe anytime.