Frost dates for 37931 — Knoxville, TN
Last spring frostMar 31median date
First fall frostNov 4median date
Growing season218 daysfrost-free
Hardiness zone7bZone 7b
How Knoxville compares
- In 8 years out of 10, the last spring frost in Knoxville falls between March 11 and April 15, a 35-day window. The first fall frost falls between October 22 and November 18.
- The median last frost is 7 days earlier than the Tennessee median of Apr 7.
- Its 218-day growing season is longer than 86% of the 548 Tennessee places with a regular frost season (state median 206 days).
- The last frost is 5 days earlier than the zone 7b median of Apr 5. Hardiness zones measure winter cold, not season length, so use these dates rather than a zone 7b chart.
- The weather station records an average of 68 nights a year at or below 32°F.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | March 11 |
| 50% (median) | March 31 |
| 10% (safe for tender plants) | April 15 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | October 22 |
| 50% (median) | November 4 |
| 90% (late) | November 18 |
Frost here means 32°F (0°C). A median date means half of years have their last frost earlier and half later.
Planting calendar for Knoxville, TN
Frost dates for 37931 — Knoxville, TN — last frost Mar 31, first frost Nov 4, zone 7b. whenisthelastfrost.com
Crop
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Start indoors: Jan 6 to Jan 20Transplant outside: Mar 3 to Mar 17
Start indoors: Jan 20 to Feb 3Transplant outside: Apr 14 to Apr 28
Start indoors: Jan 20 to Feb 3Transplant outside: Apr 14 to Apr 28
Start indoors: Feb 3 to Feb 17Transplant outside: Apr 7 to Apr 21
Start indoors: Feb 3 to Feb 17Transplant outside: Mar 10 to Mar 24Sow outdoors: Mar 3 to Apr 7Plant for fall: Sep 9 to Oct 7
Start indoors: Feb 3 to Feb 17Transplant outside: Mar 3 to Mar 17Sow outdoors: Mar 3 to Mar 17Plant for fall: Aug 26 to Sep 16
Start indoors: Feb 3 to Feb 17Transplant outside: Mar 17 to Mar 31Plant for fall: Jul 29 to Aug 19
Start indoors: Feb 3 to Feb 17Transplant outside: Mar 10 to Mar 24Plant for fall: Jul 29 to Aug 19
Start indoors: Feb 3 to Feb 17Transplant outside: Mar 17 to Mar 31Plant for fall: Jul 29 to Aug 19
Start indoors: Feb 17 to Mar 3Transplant outside: Apr 21 to May 5Sow outdoors: Apr 21 to May 5
Start indoors: Feb 17 to Mar 3Transplant outside: Apr 7 to Apr 21
Sow outdoors: Feb 17 to Mar 10Plant for fall: Aug 12 to Sep 2
Sow outdoors: Feb 17 to Mar 10Plant for fall: Sep 9 to Sep 30
Sow outdoors: Feb 24 to Apr 7Plant for fall: Sep 23 to Oct 14
Start indoors: Mar 3 to Mar 10Transplant outside: Apr 14 to Apr 21Sow outdoors: Apr 7 to Apr 21Plant for fall: Aug 19 to Sep 2
Start indoors: Mar 3 to Mar 10Sow outdoors: Apr 7 to Apr 21Plant for fall: Aug 26 to Sep 9
Start indoors: Mar 3 to Mar 10Sow outdoors: Apr 7 to Apr 21
Start indoors: Mar 3 to Mar 10Transplant outside: Apr 14 to Apr 28
Sow outdoors: Mar 10 to Apr 7Plant for fall: Aug 12 to Aug 26
Sow outdoors: Mar 10 to Apr 7Plant for fall: Aug 26 to Sep 9
Sow outdoors: Mar 10 to Mar 31
Sow outdoors: Mar 17 to Apr 14Plant for fall: Aug 26 to Sep 9
Sow outdoors: Mar 17 to Apr 7Plant for fall: Sep 9 to Sep 30
Sow outdoors: Apr 7 to Apr 28Plant for fall: Aug 19 to Sep 2
Sow outdoors: Apr 7 to Apr 21
Transplant outside: Apr 14 to May 5
Plant for fall: Oct 21 to Nov 25
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Knoxville, TN
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Jan 6 – Jan 20 | Mar 3 – Mar 17 | — | — |
| Peppers | Jan 20 – Feb 3 | Apr 14 – Apr 28 | — | — |
| Eggplant | Jan 20 – Feb 3 | Apr 14 – Apr 28 | — | — |
| Tomatoes | Feb 3 – Feb 17 | Apr 7 – Apr 21 | — | — |
| Lettuce | Feb 3 – Feb 17 | Mar 10 – Mar 24 | Mar 3 – Apr 7 | Sep 9 – Oct 7 |
| Kale | Feb 3 – Feb 17 | Mar 3 – Mar 17 | Mar 3 – Mar 17 | Aug 26 – Sep 16 |
| Broccoli | Feb 3 – Feb 17 | Mar 17 – Mar 31 | — | Jul 29 – Aug 19 |
| Cabbage | Feb 3 – Feb 17 | Mar 10 – Mar 24 | — | Jul 29 – Aug 19 |
| Cauliflower | Feb 3 – Feb 17 | Mar 17 – Mar 31 | — | Jul 29 – Aug 19 |
| Okra | Feb 17 – Mar 3 | Apr 21 – May 5 | Apr 21 – May 5 | — |
| Basil | Feb 17 – Mar 3 | Apr 7 – Apr 21 | — | — |
| Peas | — | — | Feb 17 – Mar 10 | Aug 12 – Sep 2 |
| Spinach | — | — | Feb 17 – Mar 10 | Sep 9 – Sep 30 |
| Radishes | — | — | Feb 24 – Apr 7 | Sep 23 – Oct 14 |
| Cucumbers | Mar 3 – Mar 10 | Apr 14 – Apr 21 | Apr 7 – Apr 21 | Aug 19 – Sep 2 |
| Zucchini & Summer Squash | Mar 3 – Mar 10 | — | Apr 7 – Apr 21 | Aug 26 – Sep 9 |
| Winter Squash & Pumpkins | Mar 3 – Mar 10 | — | Apr 7 – Apr 21 | — |
| Melons & Watermelon | Mar 3 – Mar 10 | Apr 14 – Apr 28 | — | — |
| Carrots | — | — | Mar 10 – Apr 7 | Aug 12 – Aug 26 |
| Beets | — | — | Mar 10 – Apr 7 | Aug 26 – Sep 9 |
| Potatoes | — | — | Mar 10 – Mar 31 | — |
| Swiss Chard | — | — | Mar 17 – Apr 14 | Aug 26 – Sep 9 |
| Cilantro | — | — | Mar 17 – Apr 7 | Sep 9 – Sep 30 |
| Green Beans | — | — | Apr 7 – Apr 28 | Aug 19 – Sep 2 |
| Sweet Corn | — | — | Apr 7 – Apr 21 | — |
| Sweet Potatoes | — | Apr 14 – May 5 | — | — |
| Garlic | — | — | — | Oct 21 – Nov 25 |
Dates come from the median frost dates and common extension-service timing. Adjust for your soil temperature, microclimate and the varieties you grow.
About these dates
Based on 1991–2020 NOAA climate normals for the Oak Ridge Asos, TN weather station, 11 km away (elevation 909 ft (277 m)).
ZIP codes in Knoxville: 37901 37902 37909 37912 37914 37915 37916 37917 37918 37919 37920 37921 37922 37923 37924 37927 37928 37929 37930 37931 37932 37933 37934 37938 37939 37940 37950 37995 37996 37997 37998
Frost dates near Knoxville
- Powell Apr 11 · Oct 28
- Oak Ridge Mar 31 · Nov 4
- Clinton Mar 31 · Nov 4
- Heiskell Apr 22 · Oct 25
- Louisville Apr 1 · Nov 2
- Oliver Springs Apr 5 · Nov 1
- Andersonville Apr 22 · Oct 25
- Norris Apr 22 · Oct 25
Frequently asked questions
When is the last frost in Knoxville, TN?
The median last spring frost in Knoxville, TN is March 31. There is still about a 10% chance of frost after April 15, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Knoxville, TN?
The median first fall frost is November 4, with about a 10% chance of frost before October 22.
How long is the growing season in Knoxville, TN?
About 218 days between the median last spring frost and first fall frost.
What planting zone is Knoxville, TN?
Knoxville, TN is in USDA hardiness zone 7b.