Larchwood, IA frost dates
How Larchwood compares
- In 8 years out of 10, the last spring frost in Larchwood falls between April 19 and May 15, a 26-day window. The first fall frost falls between September 19 and October 16.
- The median last frost is 4 days later than the Iowa median of Apr 28.
- Its 153-day growing season is longer than 6% of the 934 Iowa places with a regular frost season (state median 165 days).
- The last frost is typical for zone 5a, where the median is May 3.
- The weather station records an average of 160 nights a year at or below 32°F.
- Compared with Sioux Falls, SD, 31 km away, the last frost here is 6 days later than there and the growing season is 17 days shorter.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 19 |
| 50% (median) | May 2 |
| 10% (safe for tender plants) | May 15 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 19 |
| 50% (median) | October 2 |
| 90% (late) | October 16 |
Frost here means 32°F (0°C). A median date means half of years have their last frost earlier and half later.
Planting calendar for Larchwood, IA
Larchwood, IA frost dates — last frost May 2, first frost Oct 2, zone 5a. whenisthelastfrost.com
When to plant vegetables in Larchwood, IA
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Feb 7 – Feb 21 | Apr 4 – Apr 18 | — | — |
| Peppers | Feb 21 – Mar 7 | May 16 – May 30 | — | — |
| Eggplant | Feb 21 – Mar 7 | May 16 – May 30 | — | — |
| Tomatoes | Mar 7 – Mar 21 | May 9 – May 23 | — | — |
| Lettuce | Mar 7 – Mar 21 | Apr 11 – Apr 25 | Apr 4 – May 9 | Aug 7 – Sep 4 |
| Kale | Mar 7 – Mar 21 | Apr 4 – Apr 18 | Apr 4 – Apr 18 | Jul 24 – Aug 14 |
| Broccoli | Mar 7 – Mar 21 | Apr 18 – May 2 | — | Jun 26 – Jul 17 |
| Cabbage | Mar 7 – Mar 21 | Apr 11 – Apr 25 | — | Jun 26 – Jul 17 |
| Cauliflower | Mar 7 – Mar 21 | Apr 18 – May 2 | — | Jun 26 – Jul 17 |
| Okra | Mar 21 – Apr 4 | May 23 – Jun 6 | May 23 – Jun 6 | — |
| Basil | Mar 21 – Apr 4 | May 9 – May 23 | — | — |
| Peas | — | — | Mar 21 – Apr 11 | Jul 10 – Jul 31 |
| Spinach | — | — | Mar 21 – Apr 11 | Aug 7 – Aug 28 |
| Radishes | — | — | Mar 28 – May 9 | Aug 21 – Sep 11 |
| Cucumbers | Apr 4 – Apr 11 | May 16 – May 23 | May 9 – May 23 | Jul 17 – Jul 31 |
| Zucchini & Summer Squash | Apr 4 – Apr 11 | — | May 9 – May 23 | Jul 24 – Aug 7 |
| Winter Squash & Pumpkins | Apr 4 – Apr 11 | — | May 9 – May 23 | — |
| Melons & Watermelon | Apr 4 – Apr 11 | May 16 – May 30 | — | — |
| Carrots | — | — | Apr 11 – May 9 | Jul 10 – Jul 24 |
| Beets | — | — | Apr 11 – May 9 | Jul 24 – Aug 7 |
| Potatoes | — | — | Apr 11 – May 2 | — |
| Swiss Chard | — | — | Apr 18 – May 16 | Jul 24 – Aug 7 |
| Cilantro | — | — | Apr 18 – May 9 | Aug 7 – Aug 28 |
| Green Beans | — | — | May 9 – May 30 | Jul 17 – Jul 31 |
| Sweet Corn | — | — | May 9 – May 23 | — |
| Sweet Potatoes | — | May 16 – Jun 6 | — | — |
| Garlic | — | — | — | Sep 18 – Oct 23 |
Dates come from the median frost dates and common extension-service timing. Adjust for your soil temperature, microclimate and the varieties you grow.
About these dates
Based on 1991–2020 NOAA climate normals for the Canton, SD weather station, 19 km away (elevation 1,316 ft (401 m)).
Frost dates near Larchwood
- Lester May 1 · Oct 4
- Inwood May 2 · Oct 2
- Alvord May 1 · Oct 4
- Rock Rapids May 1 · Oct 4
- Doon May 1 · Oct 4
- Rock Valley Apr 30 · Oct 3
- Hull Apr 30 · Oct 3
- George May 1 · Oct 4
- Little Rock May 5 · Oct 3
- Boyden May 5 · Sep 28
Frequently asked questions
When is the last frost in Larchwood, IA?
The median last spring frost in Larchwood, IA is May 2. There is still about a 10% chance of frost after May 15, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Larchwood, IA?
The median first fall frost is October 2, with about a 10% chance of frost before September 19.
How long is the growing season in Larchwood, IA?
About 153 days between the median last spring frost and first fall frost.
What planting zone is Larchwood, IA?
Larchwood, IA is in USDA hardiness zone 5a.