Lawrence, Kansas: planting zone & frost dates
Lawrence is in USDA plant hardiness zone 6b, where the average coldest winter night reaches -5 to 0°F (-20.6 to -17.8°C). The typical last spring frost is around Apr 17 and the first fall frost around Oct 22.
Frost dates
| Probability | Last spring frost (32°F) | First fall frost (32°F) |
|---|---|---|
| Safer (10% risk) | Apr 24 | Oct 14 |
| Typical planning date (30% risk) | Apr 17 | Oct 22 |
| Median (50%) | Apr 12 | Oct 28 |
How to read this: after the spring "10% risk" date, a 32°F frost happens in only about 1 year in 10. In fall, the "10% risk" date is the early end — a frost before it happens about 1 year in 10.
Frost data comes from NOAA station LAWRENCE, KS (USC00144559), 0.7 mi (1.2 km) from the city center and 72 ft higher than the city center (+22 m). Record used for the 1991–2020 normals: 20 years.
Why your yard may differ from the station: microclimates.
Hardiness zone across Lawrence
All 5 ZIP codes covering Lawrence are in zone 6b.
Vegetable planting calendar for Lawrence
Dates are counted from the 30%-risk frost dates above (last frost Apr 17, first frost Oct 22). Shift a week later in cold spots or low-lying ground.
| Crop | Start indoors | Transplant / plant out | Direct sow | Fall crop sow/plant |
|---|---|---|---|---|
| Tomato | Feb 20 – Mar 6 | Apr 24 – May 8 | — | — |
| Pepper | Feb 6 – Feb 20 | May 1 – May 15 | — | — |
| Lettuce | Mar 6 – Mar 20 | Apr 3 – Apr 24 | Mar 20 – May 1 | Aug 13 – Sep 10 |
| Green Beans | — | — | Apr 24 – May 29 | Jul 30 – Aug 13 |
| Sweet Corn | — | — | Apr 24 – May 22 | — |
| Zucchini & Summer Squash | Mar 20 – Mar 27 | Apr 24 – May 8 | Apr 24 – May 15 | Jul 30 – Aug 13 |
| Cucumber | Mar 20 – Mar 27 | May 1 – May 8 | Apr 24 – May 15 | Jul 30 – Aug 13 |
| Carrot | — | — | Mar 27 – May 1 | Jul 30 – Aug 13 |
| Onion | Jan 23 – Feb 6 | Mar 20 – Apr 3 | — | — |
| Potato | — | Mar 20 – Apr 10 | — | — |
| Basil | Mar 6 – Mar 20 | May 1 – May 15 | May 1 – May 22 | — |
| Spinach | — | — | Mar 6 – Apr 3 | Aug 27 – Sep 24 |
| Kale | Feb 20 – Mar 6 | Mar 20 – Apr 10 | Mar 20 – Apr 10 | Aug 13 – Sep 10 |
| Broccoli | Feb 20 – Mar 6 | Apr 3 – Apr 24 | — | Jul 30 – Aug 13 |
| Peas | — | — | Mar 6 – Mar 27 | Aug 13 – Aug 27 |
| Eggplant | Feb 6 – Feb 20 | May 1 – May 15 | — | — |
| Cabbage | Feb 20 – Mar 6 | Mar 20 – Apr 3 | — | Jul 30 – Aug 13 |
| Radish | — | — | Mar 13 – May 1 | Sep 10 – Oct 8 |
| Strawberry | — | Mar 20 – Apr 10 | — | — |
| Beets | — | — | Mar 27 – May 8 | Aug 13 – Aug 27 |
Nearby cities in Kansas
- Topeka — zone 6b, last frost Apr 20, first frost Oct 17
- Olathe — zone 6b, last frost Apr 16, first frost Oct 23
- Kansas City — zone 6b, last frost Apr 10, first frost Oct 29
- Overland Park — zone 6b, last frost Apr 16, first frost Oct 23
- Wichita — zone 7a, last frost Apr 16, first frost Oct 21
More: all Kansas cities · other zone 6b cities: Columbus, OH, Indianapolis, IN, Boston, MA, Detroit, MI, Kansas City, MO, Cincinnati, OH, Pittsburgh, PA, Buffalo, NY
Lawrence gardening questions
When is the last frost in Lawrence, KS?
Plan around Apr 17. At NOAA's Lawrence, KS station, 0.7 mi from the city center, there is a 30% chance of a 32°F frost after that date. Half of springs have their last frost by Apr 12, and after Apr 24 the risk drops to about 1 in 10. A hard freeze (28°F) usually ends earlier, around Apr 3. The last frost is fairly predictable here: only 25 days separate the 90% and 10% dates (median for cities on this site: 36 days).
When should I plant tomatoes in Lawrence, KS?
Start seeds indoors Feb 20 – Mar 6 and set transplants outside Apr 24 – May 8, once nights stay above 50°F and the soil is near 60°F. That leaves 188 days between the 30% frost dates, enough for most varieties including 80–85-day slicers. More: tomato planting dates by zone.
How long is the growing season in Lawrence?
About 199 days without a 32°F frost in a typical (median) year. In 9 years out of 10 the season lasts at least 178 days, and in 1 year in 10 it runs 217 days or more. In fall there is a 10% chance of frost by Oct 14 and a 30% chance by Oct 22. That ranks 5th longest of 6 Kansas cities on this site.
When should I plant a fall garden in Lawrence?
Count back from the first fall frost (Oct 22): transplant broccoli Jul 30 – Aug 13; sow kale Aug 13 – Sep 10; sow lettuce Aug 13 – Sep 10; sow radishes Sep 10 – Oct 8. Hardy crops keep growing through light frosts; the median 28°F hard freeze here is Nov 4. How the math works: succession and fall planting.
Did Lawrence's hardiness zone change on the 2023 map?
Yes. Most of Lawrence was zone 6a on the 2012 map and is zone 6b on the 2023 map — half a zone warmer, like about 56% of U.S. ZIP codes. The shift comes from a newer 1991–2020 averaging period plus more weather stations and better mapping; it does not mean last frost comes earlier. Why the 2023 map is warmer.
How does Lawrence compare with Topeka, KS?
Both are in zone 6b. The typical last spring frost in Lawrence (Apr 17) comes about the same time as in Topeka, KS (Apr 20), 24 miles away, and the first fall frost is Oct 22 versus Oct 17. The two cities use different NOAA stations.