Folsom, California: planting zone & frost dates
Folsom is in USDA plant hardiness zone 9b, where the average coldest winter night reaches 25 to 30°F (-3.9 to -1.1°C). The typical last spring frost is around Jan 22 and the first fall frost around Dec 7.
Frost dates
| Probability | Last spring frost (32°F) | First fall frost (32°F) |
|---|---|---|
| Safer (10% risk) | Feb 8 | Nov 28 |
| Typical planning date (30% risk) | Jan 22 | Dec 7 |
| Median (50%) | Jan 12 | Dec 16 |
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 SACRAMENTO 5 ESE, CA (USW00023271), 16.7 mi (26.9 km) from the city center and 285 ft lower than the city center (-87 m). Record used for the 1991–2020 normals: 30 years.
Why your yard may differ from the station: microclimates.
Hardiness zone across Folsom
All 2 ZIP codes covering Folsom are in zone 9b.
Vegetable planting calendar for Folsom
Dates are counted from the 30%-risk frost dates above (last frost Jan 22, first frost Dec 7). Shift a week later in cold spots or low-lying ground.
| Crop | Start indoors | Transplant / plant out | Direct sow | Fall crop sow/plant |
|---|---|---|---|---|
| Tomato | Nov 27 – Dec 11 | Jan 29 – Feb 12 | — | — |
| Pepper | Nov 13 – Nov 27 | Feb 5 – Feb 19 | — | — |
| Lettuce Mild winters: fall and winter plantings are usually more reliable than spring. | Dec 11 – Dec 25 | Jan 8 – Jan 29 | Dec 25 – Feb 5 | Sep 28 – Oct 26 |
| Green Beans | — | — | Jan 29 – Mar 5 | Sep 14 – Sep 28 |
| Sweet Corn | — | — | Jan 29 – Feb 26 | — |
| Zucchini & Summer Squash | Dec 25 – Jan 1 | Jan 29 – Feb 12 | Jan 29 – Feb 19 | Sep 14 – Sep 28 |
| Cucumber | Dec 25 – Jan 1 | Feb 5 – Feb 12 | Jan 29 – Feb 19 | Sep 14 – Sep 28 |
| Carrot Mild winters: fall and winter plantings are usually more reliable than spring. | — | — | Jan 1 – Feb 5 | Sep 14 – Sep 28 |
| Onion Mild winters: fall and winter plantings are usually more reliable than spring. | Oct 30 – Nov 13 | Dec 25 – Jan 8 | — | — |
| Potato Mild winters: fall and winter plantings are usually more reliable than spring. | — | Dec 25 – Jan 15 | — | — |
| Basil | Dec 11 – Dec 25 | Feb 5 – Feb 19 | Feb 5 – Feb 26 | — |
| Spinach Mild winters: fall and winter plantings are usually more reliable than spring. | — | — | Dec 11 – Jan 8 | Oct 12 – Nov 9 |
| Kale Mild winters: fall and winter plantings are usually more reliable than spring. | Nov 27 – Dec 11 | Dec 25 – Jan 15 | Dec 25 – Jan 15 | Sep 28 – Oct 26 |
| Broccoli Mild winters: fall and winter plantings are usually more reliable than spring. | Nov 27 – Dec 11 | Jan 8 – Jan 29 | — | Sep 14 – Sep 28 |
| Peas Mild winters: fall and winter plantings are usually more reliable than spring. | — | — | Dec 11 – Jan 1 | Sep 28 – Oct 12 |
| Eggplant | Nov 13 – Nov 27 | Feb 5 – Feb 19 | — | — |
| Cabbage Mild winters: fall and winter plantings are usually more reliable than spring. | Nov 27 – Dec 11 | Dec 25 – Jan 8 | — | Sep 14 – Sep 28 |
| Radish Mild winters: fall and winter plantings are usually more reliable than spring. | — | — | Dec 18 – Feb 5 | Oct 26 – Nov 23 |
| Strawberry | — | Dec 25 – Jan 15 | — | — |
| Beets Mild winters: fall and winter plantings are usually more reliable than spring. | — | — | Jan 1 – Feb 12 | Sep 28 – Oct 12 |
Nearby cities in California
- Rancho Cordova — zone 9b, last frost Jan 22, first frost Dec 7
- Citrus Heights — zone 9b, last frost Jan 22, first frost Dec 7
- Roseville — zone 9b, last frost Mar 5, first frost Nov 17
- Sacramento — zone 9b, last frost Jan 22, first frost Dec 7
- Elk Grove — zone 9b, last frost Feb 17, first frost Nov 26
- Stockton — zone 9b, last frost Feb 19, first frost Nov 28
More: all California cities · other zone 9b cities: Houston, TX, Phoenix, AZ, Jacksonville, FL, San Jose, CA, Fresno, CA, Sacramento, CA, Mesa, AZ, Bakersfield, CA
Folsom gardening questions
When is the last frost in Folsom, CA?
Plan around Jan 22. At NOAA's Sacramento 5 ESE, CA station, 16.7 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 Jan 12, and after Feb 8 the risk drops to about 1 in 10. A hard freeze (28°F) usually ends earlier, around Dec 31. Springs here are erratic: 52 days separate the 90% and 10% dates, versus a median of 36 days for cities on this site, so watch the forecast rather than the calendar.
When should I plant tomatoes in Folsom, CA?
Start seeds indoors Nov 27 – Dec 11 and set transplants outside Jan 29 – Feb 12, once nights stay above 50°F and the soil is near 60°F. With about 319 frost-free days, frost is not the main limit — fruit set drops when nights stay above about 75°F, so early plantings tend to do best. More: tomato planting dates by zone.
How long is the growing season in Folsom?
About 341 days without a 32°F frost in a typical (median) year. In 9 years out of 10 the season lasts at least 308 days, and in 1 year in 10 it runs 365 days or more. In fall there is a 10% chance of frost by Nov 28 and a 30% chance by Dec 7. That ranks 44th longest of 84 California cities on this site.
When should I plant a fall garden in Folsom?
Count back from the first fall frost (Dec 7): transplant broccoli Sep 14 – Sep 28; sow kale Sep 28 – Oct 26; sow lettuce Sep 28 – Oct 26; sow radishes Oct 26 – Nov 23. Hardy crops keep growing through light frosts; the median 28°F hard freeze here is Dec 25. How the math works: succession and fall planting.
Did Folsom's hardiness zone change on the 2023 map?
No. Going by the zone that covers most of the city's land, Folsom is zone 9b on both the 2012 and the 2023 USDA maps (PRISM/OSU ZIP listings). About 42% of U.S. ZIP codes kept their half-zone in 2023. Why the 2023 map is warmer.
How does Folsom compare with Roseville, CA?
Both are in zone 9b. The typical last spring frost in Folsom (Jan 22) comes about 42 days earlier than in Roseville, CA (Mar 5), 12 miles away, and the first fall frost is Dec 7 versus Nov 17. Folsom sits about 179 ft higher, which explains part of the gap. The two cities use different NOAA stations.