USDA zone 8a in Tennessee
USDA plant hardiness zone 8a covers 12 locations across Tennessee (average annual extreme minimum 10 to 15 °F): Atoka, TN, Brownsville, TN, Chattanooga, TN, Chattanooga, TN, Halls, TN, Jasper, TN, and 6 more. Average last spring frost across this group ranges March 16 (Memphis) to April 7 (Jasper), and growing seasons run 206–244 days (McDonald to Memphis) — even within one state, because hardiness sets winter survival, not planting dates. The table below gives every Tennessee location's own frost dates; the printable planting calendar uses Atoka, this group's median-season location.
- USDA zone
- 8a10 to 15 °F
- Last frost range
- Mar 16–Apr 7avg, 32°F
- First frost range
- Oct 30–Nov 16avg, 32°F
- Growing season range
- 206–244days
Locations in this group
Every location below shares this zone and a nearby weather station, but keeps its own frost dates — find your town for its own numbers, or use the ZIP planner on the home page for an instant personalized answer.
| Location | Also covers | Nearest station | Last frost | First frost | Season (days) |
|---|---|---|---|---|---|
| Atoka * | Covington, Munford, Gallaway, Brighton, Gilt Edge, Henning, +2 more | Covington 3 Sw | Mar 27 | Nov 4 | 222 |
| Brownsville | Stanton | Brownsville | Mar 29 | Nov 5 | 221 |
| Chattanooga | — | Lookout Mtn-point Park | Mar 31 | Nov 6 | 219 |
| Chattanooga | Apison, Collegedale, Middle Valley, Cohutta, Ringgold, Varnell, +5 more | Chattanooga Lovell Ap | Mar 24 | Nov 9 | 230 |
| Halls | Henning | Ripley | Mar 26 | Nov 6 | 227 |
| Jasper | — | Bridgeport 5 Nw | Apr 7 | Oct 31 | 208 |
| McDonald | Conasauga | Cleveland Fltr Plt | Apr 6 | Oct 30 | 206 |
| Memphis | West Memphis, Millington, Marion, Gilmore, Turrell, Edmondson, +3 more | W Memphis | Mar 19 | Nov 10 | 235 |
| Memphis | Collierville, Bartlett, Arlington, Lakeland, Millington, Germantown | Memphis Wfo | Mar 29 | Nov 5 | 223 |
| Memphis | Southaven, Horn Lake, Lakeview | Memphis Intl Ap | Mar 16 | Nov 16 | 244 |
| Oakland | Rossville, Williston, Moscow | Moscow | Mar 29 | Nov 3 | 219 |
| Somerville | — | Ames Plantation | Apr 1 | Nov 3 | 217 |
* Atoka is this group's median-season location — the calendar below is computed from its data.
Data: NOAA NCEI U.S. Climate Normals 1991–2020 (public domain) and USDA Plant Hardiness Zone Map 2023. Planting windows synthesized from U.S. Cooperative Extension guides.
Planting calendar (Atoka, representative)
Computed from Atoka's average frost dates — the median-season location in this Tennesseezone 8a group. hatched = start seeds indoors, solid green = plant out, teal = a fall sowing, and the terracotta dot marks the estimated first harvest. Ranges are extension-guide planning guidance, not guarantees — your own location's dates may run a week or two earlier or later (see the table above).
- Start indoors
- Plant out
- Fall sowing
- First harvest
| Crop | Frost tolerance | Start indoors | Plant out | First harvest | Fall planting | Season fit |
|---|---|---|---|---|---|---|
| Tomato | Tender | Jan 30 – Feb 13 | Apr 3 – Apr 10 | Jun 2 – Jun 22 | — | matures comfortably |
| Pepper | Very tender | Jan 16 – Jan 30 | Apr 10 – Apr 17 | Jun 9 – Jul 9 | — | matures comfortably |
| Cucumber | Tender | Feb 27 – Mar 6 | Apr 3 – Apr 10 | May 23 – Jun 12 | — | matures comfortably |
| Summer squash / zucchini | Tender | — | Apr 3 – Apr 10 | May 18 – Jun 2 | — | matures comfortably |
| Bush bean | Tender | — | Apr 3 – Apr 10 | May 23 – Jun 2 | Sep 5 – Sep 15 | matures comfortably |
| Sweet corn | Tender | — | Mar 27 – Apr 10 | May 26 – Jun 25 | — | matures comfortably |
| Basil | Very tender | Feb 13 – Feb 27 | Apr 3 – Apr 10 | May 3 – May 18 | — | matures comfortably |
| Lettuce | Half-hardy | Feb 13 – Feb 27 | Feb 27 – Mar 13 | Apr 13 – Apr 28 | Aug 22 – Sep 6 | matures comfortably |
| Pea | Hardy | — | Feb 13 – Feb 27 | Apr 9 – Apr 24 | Aug 12 – Aug 27 | matures comfortably |
| Spinach | Hardy | — | Feb 13 – Feb 27 | Mar 25 – Apr 4 | Sep 1 – Sep 11 | matures comfortably |
| Carrot | Half-hardy | — | Mar 6 – Mar 13 | May 5 – May 25 | Aug 2 – Aug 22 | matures comfortably |
| Broccoli | Half-hardy | Jan 30 – Feb 13 | Feb 27 – Mar 13 | Apr 23 – May 13 | Aug 7 – Aug 27 | matures comfortably |
Which crops fit this growing season
Using Atoka's own 222-day growing season (32°F, NOAA 1991–2020 median) against each crop's real days-to-maturity range: 12 of 12 crops mature here with comfortable margin. A different location in the table above with a longer or shorter season will get a different mix — the ZIP planner on the home page gives your own.
Frost & freeze dates (Atoka)
From NOAA's 1991–2020 Climate Normals at station USC00402108. The median (p50) is the average date; the 90%-safe column is the date the freeze has passed in about 9 years out of 10 — the conservative date to plant after or harvest before.
| Threshold | Last spring — avg | Last spring — 90%-safe | First fall — avg | First fall — 90%-safe | Season (days) |
|---|---|---|---|---|---|
| 36°F | Apr 7 | Apr 26 | Oct 26 | Nov 6 | 200 |
| 32°F (freeze) | Mar 27 | Apr 11 | Nov 4 | Nov 21 | 222 |
| 28°F | Mar 14 | Apr 2 | Nov 16 | Dec 6 | 248 |
| 24°F | Mar 3 | Mar 20 | Nov 30 | Dec 21 | 273 |
Growing degree days
Growing degree days (GDD) accumulate warmth above a base temperature over the year — a better predictor of crop development than the calendar alone. This group's median GDD (base 50°F) across all 12 locations is 5,152; Atoka's own reading is shown below.
| Model | °F·days | Used for |
|---|---|---|
| Base 50°F (warm-season) | 4,713 | standard warm-season base (tomato, corn, beans) |
| Base 40°F (cool-season) | 7,501 | cool-season crops (brassicas, greens) |
Hardiness zone 8a in Tennessee
Zone 8a means an average annual extreme minimum winter temperature of about 10 to 15 °F on the USDA's 2023 map — the number that tells you which perennials, shrubs, and trees reliably survive an average winter here. It does not set your planting dates, which come from the frost calendar above. Tennessee spans 4 hardiness zones in this dataset — see all Tennessee locations for the full range, including zones6b, 7a, 7b.
Explore zone 8a in other states at zone 8a, or see all USDA hardiness zones.
Frequently asked questions
- What does USDA hardiness zone 8a mean in Tennessee?
- Zone 8a means an average annual extreme minimum winter temperature of 10 to 15 °F — the standard USDA measure of which perennials survive winter. 12 locations in Tennessee fall in this zone. It does not set planting dates; see the frost calendar below for that.
- Where in Tennessee's zone 8a is the growing season longest?
- Memphis runs the longest season on this page at about 244 days; McDonald is shortest at about 206 days — they share the same hardiness zone, but they sit at different weather stations, so their frost calendars differ.
- When should I plant tomatoes in Tennessee's zone 8a?
- Using Atoka's frost dates (this page's median-season location): start seeds indoors about Jan 30 – Feb 13, then transplant outside about Apr 3 – Apr 10. Your own location in the table above may differ by a week or two — use the ZIP planner on the home page for your exact station's dates.
- Does every location in Tennessee's zone 8a have the same frost dates?
- No — they do not all share a weather station, so frost dates vary by a week or more across the 12 locations listed (see the table above for each location's own dates).
Sources & method
Frost, freeze, growing-season, and growing-degree-day figures are NOAA NCEI U.S. Climate Normals 1991–2020, one reading per location's own nearest station (see the table above). The hardiness zone is the USDA Plant Hardiness Zone Map 2023, matched to each location's ZIP. Planting windows are computed by counting from the average last and first frost using per-crop offsets synthesized from U.S. Cooperative Extension guides — the full method and citations are on the methodology page.