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Frost dates and planting calendar for Clarksville, Tennessee

Updated October 30, 2026. Based on USDA, NOAA and Colorado State University Extension data. Published by Humblebee.

USDA hardiness zone
7b[1]
Median last spring frost
Apr 3[2]
Median first fall frost
Nov 1[3]
Growing season, median
212 days[4]

Clarksville, Tennessee is in USDA hardiness zone 7b[1]. The median last spring frost at the nearby NOAA station is April 3[2].

Frost dates

JanFebMarAprMayJunJulAugSepOctNovDecLast spring frost: 9 in 10 years after Mar 19, half of years Apr 3, 1 in 10 years after Apr 20Last frostmedian Apr 3First fall frost: 9 in 10 years before Nov 14, half of years Nov 1, 1 in 10 years before Oct 20First frostmedian Nov 1Frost riskHardyHardy vegetables: plant Mar 6 to Mar 20Mar 6 to Mar 20Semi-hardySemi-hardy vegetables: plant Mar 20 to Apr 3Mar 20 to Apr 3TenderTender vegetables: plant around Apr 3around Apr 3Very tenderVery tender vegetables: plant from Apr 17from Apr 17
Shaded: the span between the dates frost passes in 9 of 10 years and 1 of 10 years[2][3]. Green: planting windows from the CSU rules applied to the median last frost (GardenFacts calculation)[6]. Exact dates are in the tables below.

These frost dates are odds from NOAA records for 1991 to 2020, not a forecast. They come from the Clarksville Wwtp weather station[5]. The last spring frost comes after April 3 in half of years, and after April 20 in 1 of 10 years[2]. The first fall frost comes before November 1 in half of years, and before October 20 in 1 of 10 years[3]. Any year can be earlier or later.

Frost Likely (9 in 10 years) Even odds (5 in 10) Unlikely (1 in 10)
Last spring frost (32°F)[2] after March 19 after April 3 after April 20
First fall frost (32°F)[3] before October 20 before November 1 before November 14
  • Hard freeze (28°F): median last spring date March 22, median first fall date November 11[7].
  • Frost-free growing season: at least 192 days in 9 of 10 years, 212 days in half of years and 233 days in 1 of 10 years[4].
  • The low reached 32°F or colder in 100% of years and 28°F or colder in 100% of years[8].
  • Weather station: Clarksville Wwtp (USC00401790), 1.4 miles from the city center, 402 feet, 29 years of 1991 to 2020 records[5].

When to plant vegetables

Colorado State University Extension wrote its planting guide for Colorado, so these dates are a simple calculation and not local advice[6]. Hardy vegetables such as broccoli, lettuce and peas can go in as early as 2 to 4 weeks before the median last frost, which works out to March 6 to March 20[6]. Semi-hardy vegetables such as carrots and potatoes can go in as early as 2 weeks before it, from March 20 up to the median date[9]. Tender vegetables such as snap beans and sweet corn can be sown from seed around April 3[10]. Very tender vegetables such as tomatoes and peppers typically wait 2 or more weeks after it, so the earliest start is April 17[11].

  • Hardy (broccoli, cabbage, kohlrabi, lettuce, onions, peas, radishes, spinach, turnips): as early as 2 to 4 weeks before the median last frost (April 3) is March 6 to March 20[6]
  • Semi-hardy (beets, carrots, cauliflower, parsnips, potatoes, Swiss chard): as early as 2 weeks before the median last frost (April 3) is March 20, up to the median date itself[9]
  • Tender (snap beans, sweet corn, cucumbers, summer squash): from seed around the median last frost date, April 3[10]
  • Very tender (cantaloupe, eggplant, peppers, tomatoes, winter squash, watermelon): the earliest start, two weeks after the median last frost (April 3), is April 17[11]
Vegetable (CSU group) Plant from First harvest around
Broccoli (hardy)[12] Mar 6 May 10 (from transplants)
Cabbage (hardy)[12] Mar 6 May 30 (from transplants)
Kohlrabi (hardy)[12] Mar 6 Apr 25
Lettuce (hardy)[12] Mar 6 May 5
Onions (hardy)[12] Mar 6 Jun 24
Peas (hardy)[12] Mar 6 May 10
Radishes (hardy)[12] Mar 6 Apr 5
Spinach (hardy)[12] Mar 6 Apr 15
Turnips (hardy)[12] Mar 6 Apr 25
Beets (semi-hardy)[12] Mar 20 May 19
Carrots (semi-hardy)[12] Mar 20 May 29
Cauliflower (semi-hardy)[12] Mar 20 not listed
Parsnips (semi-hardy)[12] Mar 20 May 29
Potatoes (semi-hardy)[12] Mar 20 Jul 23
Swiss chard (semi-hardy)[12] Mar 20 May 19
Snap beans (tender)[12] Apr 3 Jun 2
Sweet corn (tender)[12] Apr 3 Jun 2
Cucumbers (tender)[12] Apr 3 May 28
Summer squash (tender)[12] Apr 3 May 23
Cantaloupe (very tender)[12] Apr 17 Jul 11
Eggplant (very tender)[12] Apr 17 Jun 16 (from transplants)
Peppers (very tender)[12] Apr 17 Jun 26 (from transplants)
Tomatoes (very tender)[12] Apr 17 Jun 21 (from transplants)
Winter squash (very tender)[12] Apr 17 Jul 26
Watermelon (very tender)[12] Apr 17 Jul 11
Spacing, depth and soil temperature (CSU Extension)
Vegetable Min. soil temp Depth Spacing Days to harvest
Broccoli[13] 40°F 1/2 in 18 in 65
Cabbage[13] 40°F 1/2 in 18 in 85
Kohlrabi[13] 40°F 1/2 in 7-9 in 50
Lettuce[13] 35°F 1/4 in 7-9 in 60
Onions[13] 35°F 1/4 in (seed), 1-2 in (sets) 4-6 in 110
Peas[13] 40°F 1 in 4-6 in 65
Radishes[13] 40°F 1/2 in 2-3 in 30
Spinach[13] 40°F 1/2 in 4-6 in 40
Turnips[13] 40°F 1/2 in 4-6 in 50
Beets[13] 40°F 3/4-1 in 4-6 in 60
Carrots[13] 40°F 1/4 in 2-3 in 70
Cauliflower[13] 40°F 1/2 in 18 in –
Parsnips[13] 35°F 1/2 in 5-6 in 70
Potatoes[13] 45°F – – 125
Swiss chard[13] 40°F 1 in 7-9 in 60
Snap beans[13] 55°F 1-1 1/2 in 6 in 60
Sweet corn[13] 50°F 1-1 1/2 in 12 x 30 in or 9 x 36 in 60-90
Cucumbers[13] 60°F 1 in 6 in trellised, 24-36 in untrellised 55
Summer squash[13] 60°F 1-1 1/2 in 36-48 in 50
Cantaloupe[13] 60°F 1-1 1/2 in 36-48 in 85
Eggplant[13] 60°F 1/4 in 18-24 in 60
Peppers[13] 60°F 1/4 in 15-18 in 70
Tomatoes[13] 50°F 1/4 in 24 in trellised 65
Winter squash[13] 60°F 1-1 1/2 in 36-48 in 100
Watermelon[13] 60°F 1-1 1/2 in 36-48 in 85

Hardiness zone

Zone 7b means an average yearly coldest night of 5°F to 10°F over 1991 to 2020[1]. The zone is based on winter lows, not on summer heat or frost dates[14]. Most of the city, 94% of its land area, is in ZIP code areas rated 7b, and 6% is in areas rated 7a[15].

Zone 7b: average annual extreme minimum temperature 5°F to 10°F (1991 to 2020)[1]. Modeled value at the city center: 5.5°F[1].

Share of the city's land area by ZIP code zone: zone 7b 94%, zone 7a 6%[15].

All towns in zone 7b and what zone 7b means

Zone by ZIP code
ZIP code Zone Coldest night range
37042[15] 7b 5 to 10°F
37040[15] 7b 5 to 10°F
37043[15] 7b 5 to 10°F
42223[15] 7a 0 to 5°F

Questions people ask

What growing zone is Clarksville, Tennessee?
The center of Clarksville is in USDA zone 7b[1]. By land area, 94% of the city is in ZIP code areas rated 7b and 6% in areas rated 7a[15].
When is the last frost in Clarksville?
The median last spring frost is April 3, so in half of years the last frost comes after that date[2]. In 1 of 10 years it comes after April 20[2].
When to plant tomatoes in Clarksville?
Using CSU's rule for very tender vegetables, the earliest start is April 17, which is 2 weeks after the median last frost[11]. CSU says typically 2 or more weeks after, and its guide was written for Colorado[11].
When is the first frost in Clarksville?
The median first fall frost is November 1[3]. In 1 of 10 years it comes before October 20[3].
How long is the growing season in Clarksville?
The growing season is at least 212 days in half of years[4]. It is at least 192 days in 9 of 10 years[4].

Facts and sources

  1. The 2023 USDA Plant Hardiness Zone Map puts the center of Clarksville, Tennessee in zone 7b. Zone 7b means an average annual extreme minimum temperature of 5°F to 10°F over 1991 to 2020. The map's modeled value at the city center is 5.5°F. USDA zone map 2023 (PRISM, OSU)
  2. Last spring frost (32°F) at this station: in 9 of 10 years the last frost comes after March 19, in half of years after April 3, and in 1 of 10 years after April 20 (NOAA 1991 to 2020 normals). The median last frost date is April 3. NOAA Climate Normals 1991-2020
  3. First fall frost (32°F) at this station: in 1 of 10 years the first frost comes before October 20, in half of years before November 1, and in 9 of 10 years before November 14 (NOAA 1991 to 2020 normals). The median first frost date is November 1. NOAA Climate Normals 1991-2020
  4. Growing season (days between the last spring and first fall 32°F frost) at this station: at least 192 days in 9 of 10 years, at least 212 days in half of years, and at least 233 days in 1 of 10 years. NOAA Climate Normals 1991-2020
  5. Frost dates on this page come from NOAA climate normals for the Clarksville Wwtp weather station (USC00401790), 1.4 miles from the center of Clarksville at 402 feet, using 29 years of records from 1991 to 2020. NOAA Climate Normals 1991-2020
  6. Colorado State University Extension's vegetable planting guide (written for Colorado) groups broccoli, cabbage, kohlrabi, lettuce, onions, peas, radishes, spinach, turnips as hardy vegetables, with this rule: as early as 2-4 weeks before the average last... CSU Extension GardenNotes #720
  7. Hard freeze (28°F) at this station: the median last spring date is March 22 and the median first fall date is November 11. NOAA Climate Normals 1991-2020
  8. At this station the low reached 32°F or colder in 100% of years from 1991 to 2020, and 28°F or colder in 100% of years. NOAA Climate Normals 1991-2020
  9. Colorado State University Extension's vegetable planting guide (written for Colorado) groups beets, carrots, cauliflower, parsnips, potatoes, Swiss chard as semi-hardy vegetables, with this rule: as early as 0-2 weeks before the average last spring frost.... CSU Extension GardenNotes #720
  10. Colorado State University Extension's vegetable planting guide (written for Colorado) groups snap beans, sweet corn, cucumbers, summer squash as tender vegetables, with this rule: from seed around the average last spring frost; cucumber and summer squash... CSU Extension GardenNotes #720
  11. Colorado State University Extension's vegetable planting guide (written for Colorado) groups cantaloupe, eggplant, peppers, tomatoes, winter squash, watermelon as very tender vegetables, with this rule: typically 2 or more weeks after the average last... CSU Extension GardenNotes #720
  12. GardenFacts calculation: earliest planting date plus CSU days to harvest (table on this page), from the station's median last frost. NOAA Climate Normals 1991-2020
  13. CSU Extension vegetable table: soil temperature, depth, spacing, days to harvest (table on this page). CSU Extension GardenNotes #720
  14. USDA hardiness zones are based on the average annual extreme minimum winter temperature (the coldest night of each winter, averaged over 1991 to 2020 for the 2023 map), not on summer heat or frost dates. Each zone spans 10°F and each half zone (a or b)... USDA Plant Hardiness Zone Map
  15. Clarksville, Tennessee overlaps 4 ZIP code areas. By land area, 94% lies in ZIP code areas rated zone 7b, 6% lies in ZIP code areas rated zone 7a. USDA zone map 2023 (PRISM, OSU)

Frost dates are probabilities from 1991 to 2020 weather records at one NOAA station, not a forecast. Any year can be earlier or later. The hardiness zone describes the average coldest winter night, not frost dates or summer heat. Spots inside the city can differ (ZIP table). Planting rules come from Colorado State University Extension's guide, written for Colorado. A local extension office may give dates tuned to the area. Planting and harvest dates marked GardenFacts calculation are simple arithmetic from the facts above, not advice from the source.

Hardiness zone data: USDA Plant Hardiness Zone Map (2023), USDA Agricultural Research Service and PRISM Group, Oregon State University, prism.oregonstate.edu, accessed October 30, 2026. This is not the official USDA map. Frost data: NOAA NCEI U.S. Climate Normals 1991-2020. Planting rules: Colorado State University Extension.