Chattanooga, Tennessee: planting zone & frost dates
Chattanooga is in USDA plant hardiness zone 8a, where the average coldest winter night reaches 10 to 15°F (-12.2 to -9.4°C). The typical last spring frost is around Mar 31 and the first fall frost around Nov 3.
Frost dates
| Probability | Last spring frost (32°F) | First fall frost (32°F) |
|---|---|---|
| Safer (10% risk) | Apr 8 | Oct 27 |
| Typical planning date (30% risk) | Mar 31 | Nov 3 |
| Median (50%) | Mar 24 | Nov 9 |
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 CHATTANOOGA LOVELL AP, TN (USW00013882), 3.6 mi (5.8 km) from the city center and 20 ft lower than the city center (-6 m). Record used for the 1991–2020 normals: 27 years.
Why your yard may differ from the station: microclimates.
Hardiness zone across Chattanooga
Chattanooga spans more than one half-zone. Share of the city's land area by zone (via its 17 ZIP codes): 8a (80%), 7b (20%). The headline zone is the one covering the most land. Look up your ZIP for your exact zone.
Vegetable planting calendar for Chattanooga
Dates are counted from the 30%-risk frost dates above (last frost Mar 31, first frost Nov 3). 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 3 – Feb 17 | Apr 7 – Apr 21 | — | — |
| Pepper | Jan 20 – Feb 3 | Apr 14 – Apr 28 | — | — |
| Lettuce | Feb 17 – Mar 3 | Mar 17 – Apr 7 | Mar 3 – Apr 14 | Aug 25 – Sep 22 |
| Green Beans | — | — | Apr 7 – May 12 | Aug 11 – Aug 25 |
| Sweet Corn | — | — | Apr 7 – May 5 | — |
| Zucchini & Summer Squash | Mar 3 – Mar 10 | Apr 7 – Apr 21 | Apr 7 – Apr 28 | Aug 11 – Aug 25 |
| Cucumber | Mar 3 – Mar 10 | Apr 14 – Apr 21 | Apr 7 – Apr 28 | Aug 11 – Aug 25 |
| Carrot | — | — | Mar 10 – Apr 14 | Aug 11 – Aug 25 |
| Onion | Jan 6 – Jan 20 | Mar 3 – Mar 17 | — | — |
| Potato | — | Mar 3 – Mar 24 | — | — |
| Basil | Feb 17 – Mar 3 | Apr 14 – Apr 28 | Apr 14 – May 5 | — |
| Spinach | — | — | Feb 17 – Mar 17 | Sep 8 – Oct 6 |
| Kale | Feb 3 – Feb 17 | Mar 3 – Mar 24 | Mar 3 – Mar 24 | Aug 25 – Sep 22 |
| Broccoli | Feb 3 – Feb 17 | Mar 17 – Apr 7 | — | Aug 11 – Aug 25 |
| Peas | — | — | Feb 17 – Mar 10 | Aug 25 – Sep 8 |
| Eggplant | Jan 20 – Feb 3 | Apr 14 – Apr 28 | — | — |
| Cabbage | Feb 3 – Feb 17 | Mar 3 – Mar 17 | — | Aug 11 – Aug 25 |
| Radish | — | — | Feb 24 – Apr 14 | Sep 22 – Oct 20 |
| Strawberry | — | Mar 3 – Mar 24 | — | — |
| Beets | — | — | Mar 10 – Apr 21 | Aug 25 – Sep 8 |
Nearby cities in Tennessee
- Murfreesboro — zone 7b, last frost Apr 15, first frost Oct 22
- Knoxville — zone 7b, last frost Apr 19, first frost Oct 22
- Franklin — zone 7b, last frost Apr 10, first frost Oct 25
- Nashville — zone 7b, last frost Apr 7, first frost Oct 25
- Clarksville — zone 7b, last frost Apr 10, first frost Oct 27
- Memphis — zone 8a, last frost Mar 24, first frost Nov 9
More: all Tennessee cities · other zone 8a cities: Charlotte, NC, Memphis, TN, Atlanta, GA, Raleigh, NC, Greensboro, NC, Durham, NC, Winston-Salem, NC, Chesapeake, VA
Chattanooga gardening questions
When is the last frost in Chattanooga, TN?
Plan around Mar 31. At NOAA's Chattanooga Lovell Airport, TN station, 3.6 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 Mar 24, and after Apr 8 the risk drops to about 1 in 10. A hard freeze (28°F) usually ends earlier, around Mar 11. The 90% and 10% dates are 33 days apart, close to the 36-day median for cities on this site.
When should I plant tomatoes in Chattanooga, TN?
Start seeds indoors Feb 3 – Feb 17 and set transplants outside Apr 7 – Apr 21, once nights stay above 50°F and the soil is near 60°F. That leaves 217 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 Chattanooga?
About 230 days without a 32°F frost in a typical (median) year. In 9 years out of 10 the season lasts at least 210 days, and in 1 year in 10 it runs 254 days or more. In fall there is a 10% chance of frost by Oct 27 and a 30% chance by Nov 3. That ranks 2nd longest of 7 Tennessee cities on this site.
When should I plant a fall garden in Chattanooga?
Count back from the first fall frost (Nov 3): transplant broccoli Aug 11 – Aug 25; sow kale Aug 25 – Sep 22; sow lettuce Aug 25 – Sep 22; sow radishes Sep 22 – Oct 20. Hardy crops keep growing through light frosts; the median 28°F hard freeze here is Nov 22. How the math works: succession and fall planting.
Did Chattanooga's hardiness zone change on the 2023 map?
Yes. Most of Chattanooga was zone 7b on the 2012 map and is zone 8a 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.
Is all of Chattanooga in zone 8a?
No. Zone 8a covers about 80% of the city's land; the rest is in 7b (20%), measured across the city's 17 ZIP codes. Check your own ZIP code in the table above or with the ZIP lookup.