Broken Arrow, Oklahoma: planting zone & frost dates
Broken Arrow is in USDA plant hardiness zone 7b, where the average coldest winter night reaches 5 to 10°F (-15.0 to -12.2°C). The typical last spring frost is around Apr 8 and the first fall frost around Oct 26.
Frost dates
| Probability | Last spring frost (32°F) | First fall frost (32°F) |
|---|---|---|
| Safer (10% risk) | Apr 20 | Oct 16 |
| Typical planning date (30% risk) | Apr 8 | Oct 26 |
| Median (50%) | Apr 1 | Nov 1 |
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 BIXBY, OK (USC00340782), 6.8 mi (10.9 km) from the city center and 105 ft lower than the city center (-32 m). Record used for the 1991–2020 normals: 15 years.
Why your yard may differ from the station: microclimates.
Hardiness zone across Broken Arrow
All 3 ZIP codes covering Broken Arrow are in zone 7b.
Vegetable planting calendar for Broken Arrow
Dates are counted from the 30%-risk frost dates above (last frost Apr 8, first frost Oct 26). 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 11 – Feb 25 | Apr 15 – Apr 29 | — | — |
| Pepper | Jan 28 – Feb 11 | Apr 22 – May 6 | — | — |
| Lettuce | Feb 25 – Mar 11 | Mar 25 – Apr 15 | Mar 11 – Apr 22 | Aug 17 – Sep 14 |
| Green Beans | — | — | Apr 15 – May 20 | Aug 3 – Aug 17 |
| Sweet Corn | — | — | Apr 15 – May 13 | — |
| Zucchini & Summer Squash | Mar 11 – Mar 18 | Apr 15 – Apr 29 | Apr 15 – May 6 | Aug 3 – Aug 17 |
| Cucumber | Mar 11 – Mar 18 | Apr 22 – Apr 29 | Apr 15 – May 6 | Aug 3 – Aug 17 |
| Carrot | — | — | Mar 18 – Apr 22 | Aug 3 – Aug 17 |
| Onion | Jan 14 – Jan 28 | Mar 11 – Mar 25 | — | — |
| Potato | — | Mar 11 – Apr 1 | — | — |
| Basil | Feb 25 – Mar 11 | Apr 22 – May 6 | Apr 22 – May 13 | — |
| Spinach | — | — | Feb 25 – Mar 25 | Aug 31 – Sep 28 |
| Kale | Feb 11 – Feb 25 | Mar 11 – Apr 1 | Mar 11 – Apr 1 | Aug 17 – Sep 14 |
| Broccoli | Feb 11 – Feb 25 | Mar 25 – Apr 15 | — | Aug 3 – Aug 17 |
| Peas | — | — | Feb 25 – Mar 18 | Aug 17 – Aug 31 |
| Eggplant | Jan 28 – Feb 11 | Apr 22 – May 6 | — | — |
| Cabbage | Feb 11 – Feb 25 | Mar 11 – Mar 25 | — | Aug 3 – Aug 17 |
| Radish | — | — | Mar 4 – Apr 22 | Sep 14 – Oct 12 |
| Strawberry | — | Mar 11 – Apr 1 | — | — |
| Beets | — | — | Mar 18 – Apr 29 | Aug 17 – Aug 31 |
Nearby cities in Oklahoma
- Tulsa — zone 7b, last frost Apr 5, first frost Oct 30
- Edmond — zone 7b, last frost Apr 18, first frost Oct 23
- Norman — zone 7b, last frost Apr 9, first frost Oct 29
- Oklahoma City — zone 7b, last frost Apr 10, first frost Oct 29
- Lawton — zone 7b, last frost Apr 3, first frost Nov 1
More: all Oklahoma cities · other zone 7b cities: New York, NY, Philadelphia, PA, Oklahoma City, OK, Nashville, TN, Washington, DC, Baltimore, MD, Albuquerque, NM, Tulsa, OK
Broken Arrow gardening questions
When is the last frost in Broken Arrow, OK?
Plan around Apr 8. At NOAA's Bixby, OK station, 6.8 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 1, and after Apr 20 the risk drops to about 1 in 10. A hard freeze (28°F) usually ends earlier, around Mar 17. The 90% and 10% dates are 39 days apart, close to the 36-day median for cities on this site.
When should I plant tomatoes in Broken Arrow, OK?
Start seeds indoors Feb 11 – Feb 25 and set transplants outside Apr 15 – Apr 29, once nights stay above 50°F and the soil is near 60°F. That leaves 201 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 Broken Arrow?
About 212 days without a 32°F frost in a typical (median) year. In 9 years out of 10 the season lasts at least 190 days, and in 1 year in 10 it runs 237 days or more. In fall there is a 10% chance of frost by Oct 16 and a 30% chance by Oct 26. That ranks 5th longest of 6 Oklahoma cities on this site.
When should I plant a fall garden in Broken Arrow?
Count back from the first fall frost (Oct 26): transplant broccoli Aug 3 – Aug 17; sow kale Aug 17 – Sep 14; sow lettuce Aug 17 – Sep 14; sow radishes Sep 14 – Oct 12. Hardy crops keep growing through light frosts; the median 28°F hard freeze here is Nov 9. How the math works: succession and fall planting.
Did Broken Arrow's hardiness zone change on the 2023 map?
Yes. Most of Broken Arrow was zone 7a on the 2012 map and is zone 7b 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 Broken Arrow compare with Tulsa, OK?
Both are in zone 7b. The typical last spring frost in Broken Arrow (Apr 8) comes about the same time as in Tulsa, OK (Apr 5), 9 miles away, and the first fall frost is Oct 26 versus Oct 30. The two cities use different NOAA stations.