GardenFacts

All states › Tennessee › Kingsport

Frost dates and planting calendar for Kingsport, 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 9[2]
Median first fall frost
Oct 29[3]
Growing season, median
203 days[4]

Kingsport, Tennessee is in USDA hardiness zone 7b[1]. The median last spring frost at the NOAA station is April 9, which means a last frost after that date in half of years[2].

Frost dates

JanFebMarAprMayJunJulAugSepOctNovDecLast spring frost: 9 in 10 years after Mar 25, half of years Apr 9, 1 in 10 years after Apr 25Last frostmedian Apr 9First fall frost: 9 in 10 years before Nov 10, half of years Oct 29, 1 in 10 years before Oct 15First frostmedian Oct 29Frost riskHardyHardy vegetables: plant Mar 12 to Mar 26Mar 12 to Mar 26Semi-hardySemi-hardy vegetables: plant Mar 26 to Apr 9Mar 26 to Apr 9TenderTender vegetables: plant around Apr 9around Apr 9Very tenderVery tender vegetables: plant from Apr 23from Apr 23
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.

NOAA records from 1991 to 2020 at the Kingsport weather station give the odds[5]. The last spring frost came after March 25 in 9 of 10 years, after April 9 in half of years, and after April 25 in 1 of 10 years[2]. The first fall frost came before October 15 in 1 of 10 years, before October 29 in half of years, and before November 10 in 9 of 10 years[3]. These are chances from past records, not a forecast, so any year can come earlier or later[2].

Frost Likely (9 in 10 years) Even odds (5 in 10) Unlikely (1 in 10)
Last spring frost (32°F)[2] after March 25 after April 9 after April 25
First fall frost (32°F)[3] before October 15 before October 29 before November 10
  • Hard freeze (28°F): median last spring date March 28, median first fall date November 6[7].
  • Frost-free growing season: at least 181 days in 9 of 10 years, 203 days in half of years and 223 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: Kingsport (USC00404858), 0.9 miles from the city center, 1,284 feet, 30 years of 1991 to 2020 records[5].

When to plant vegetables

Colorado State University Extension wrote its vegetable planting guide for Colorado, so the groups here are a starting point[6]. GardenFacts takes the median last frost, April 9, as the average last frost[6]. Hardy vegetables such as broccoli, lettuce and peas can go in as early as 2 to 4 weeks before it, which is March 12 to March 26[6]. Tender vegetables such as snap beans and sweet corn can be sown from seed around April 9[9]. Very tender vegetables such as tomatoes and peppers typically wait 2 or more weeks after the last frost, so the earliest start is April 23[10].

  • Hardy (broccoli, cabbage, kohlrabi, lettuce, onions, peas, radishes, spinach, turnips): as early as 2 to 4 weeks before the median last frost (April 9) is March 12 to March 26[6]
  • Semi-hardy (beets, carrots, cauliflower, parsnips, potatoes, Swiss chard): as early as 2 weeks before the median last frost (April 9) is March 26, up to the median date itself[11]
  • Tender (snap beans, sweet corn, cucumbers, summer squash): from seed around the median last frost date, April 9[9]
  • Very tender (cantaloupe, eggplant, peppers, tomatoes, winter squash, watermelon): the earliest start, two weeks after the median last frost (April 9), is April 23[10]
Vegetable (CSU group) Plant from First harvest around
Broccoli (hardy)[12] Mar 12 May 16 (from transplants)
Cabbage (hardy)[12] Mar 12 Jun 5 (from transplants)
Kohlrabi (hardy)[12] Mar 12 May 1
Lettuce (hardy)[12] Mar 12 May 11
Onions (hardy)[12] Mar 12 Jun 30
Peas (hardy)[12] Mar 12 May 16
Radishes (hardy)[12] Mar 12 Apr 11
Spinach (hardy)[12] Mar 12 Apr 21
Turnips (hardy)[12] Mar 12 May 1
Beets (semi-hardy)[12] Mar 26 May 25
Carrots (semi-hardy)[12] Mar 26 Jun 4
Cauliflower (semi-hardy)[12] Mar 26 not listed
Parsnips (semi-hardy)[12] Mar 26 Jun 4
Potatoes (semi-hardy)[12] Mar 26 Jul 29
Swiss chard (semi-hardy)[12] Mar 26 May 25
Snap beans (tender)[12] Apr 9 Jun 8
Sweet corn (tender)[12] Apr 9 Jun 8
Cucumbers (tender)[12] Apr 9 Jun 3
Summer squash (tender)[12] Apr 9 May 29
Cantaloupe (very tender)[12] Apr 23 Jul 17
Eggplant (very tender)[12] Apr 23 Jun 22 (from transplants)
Peppers (very tender)[12] Apr 23 Jul 2 (from transplants)
Tomatoes (very tender)[12] Apr 23 Jun 27 (from transplants)
Winter squash (very tender)[12] Apr 23 Aug 1
Watermelon (very tender)[12] Apr 23 Jul 17
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 the coldest night of the year averages 5°F to 10°F over 1991 to 2020[1]. The zone is about winter lows, not summer heat or frost dates[14]. By land area, all of Kingsport lies in ZIP code areas rated zone 7b[15].

Zone 7b: average annual extreme minimum temperature 5°F to 10°F (1991 to 2020)[1]. Modeled value at the city center: 6.5°F[1].

Share of the city's land area by ZIP code zone: zone 7b 100%[15].

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

Zone by ZIP code
ZIP code Zone Coldest night range
37660[15] 7b 5 to 10°F
37664[15] 7b 5 to 10°F
37663[15] 7b 5 to 10°F
37665[15] 7b 5 to 10°F
37857[15] 7b 5 to 10°F
37617[15] 7b 5 to 10°F
37659[15] 7a 0 to 5°F

Questions people ask

What growing zone is Kingsport, Tennessee?
The 2023 USDA map puts the center of Kingsport in zone 7b[1]. All of the city by land area is in ZIP code areas rated 7b[15].
When is the last frost in Kingsport?
The median last spring frost is April 9, so in half of years the last frost comes after that date[2]. In 1 of 10 years it comes after April 25[2].
When is the first frost in Kingsport?
The median first fall frost is October 29, so in half of years it comes before that date[3]. In 1 of 10 years it comes before October 15[3].
When to plant tomatoes in Kingsport?
CSU Extension says very tender vegetables like tomatoes typically wait 2 or more weeks after the average last frost[10]. For Kingsport that earliest start is April 23[10].
How long is the growing season in Kingsport?
The season between the last spring and first fall frost is at least 203 days in half of years[4]. It is at least 181 days in 9 of 10 years[4].

Facts and sources

  1. The 2023 USDA Plant Hardiness Zone Map puts the center of Kingsport, 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 6.5°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 25, in half of years after April 9, and in 1 of 10 years after April 25 (NOAA 1991 to 2020 normals). The median last frost date is April 9. 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 15, in half of years before October 29, and in 9 of 10 years before November 10 (NOAA 1991 to 2020 normals). The median first frost date is October 29. NOAA Climate Normals 1991-2020
  4. Growing season (days between the last spring and first fall 32°F frost) at this station: at least 181 days in 9 of 10 years, at least 203 days in half of years, and at least 223 days in 1 of 10 years. NOAA Climate Normals 1991-2020
  5. Frost dates on this page come from NOAA climate normals for the Kingsport weather station (USC00404858), 0.9 miles from the center of Kingsport at 1,284 feet, using 30 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 28 and the median first fall date is November 6. 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 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
  10. 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
  11. 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
  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. Kingsport, Tennessee overlaps 7 ZIP code areas. By land area, 100% lies in ZIP code areas rated zone 7b. 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.