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Frost dates and planting calendar for Bowling Green, Kentucky

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

USDA hardiness zone
7a[1]
Median last spring frost
Apr 5[2]
Median first fall frost
Oct 31[3]
Growing season, median
208 days[4]

Bowling Green, Kentucky sits in USDA hardiness zone 7a on the 2023 map[1]. The median last spring frost is April 5, which means in half of years the last frost comes after that date[2].

Frost dates

JanFebMarAprMayJunJulAugSepOctNovDecLast spring frost: 9 in 10 years after Mar 20, half of years Apr 5, 1 in 10 years after Apr 21Last frostmedian Apr 5First fall frost: 9 in 10 years before Nov 11, half of years Oct 31, 1 in 10 years before Oct 20First frostmedian Oct 31Frost riskHardyHardy vegetables: plant Mar 8 to Mar 22Mar 8 to Mar 22Semi-hardySemi-hardy vegetables: plant Mar 22 to Apr 5Mar 22 to Apr 5TenderTender vegetables: plant around Apr 5around Apr 5Very tenderVery tender vegetables: plant from Apr 19from Apr 19
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 come from NOAA climate normals for the Bowling Green Warren County Airport station, using records from 1991 to 2020[5]. In 9 of 10 years the last spring frost comes after March 20, and in 1 of 10 years it comes after April 21[2]. In the fall, the median first frost is October 31, so in half of years the first frost comes before that date[3]. In 1 of 10 years the first frost comes before October 20[3]. These are chances from past years and not a forecast, so any year can be 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 20 after April 5 after April 21
First fall frost (32°F)[3] before October 20 before October 31 before November 11
  • Hard freeze (28°F): median last spring date March 24, median first fall date November 10[7].
  • Frost-free growing season: at least 187 days in 9 of 10 years, 208 days in half of years and 229 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: Bowling Green Warren County Airport (USW00093808), 1 miles from the city center, 523 feet, 29 years of 1991 to 2020 records[5].

When to plant vegetables

Colorado State University Extension wrote its vegetable planting guide for Colorado, so treat these dates as a starting point[6]. We used the NOAA median last frost of April 5 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 the median last frost, which is March 8 to March 22[6]. Semi-hardy vegetables such as carrots and potatoes can go in as early as March 22, up to the median date itself[9]. Tender vegetables such as snap beans and sweet corn can be planted from seed around April 5[10]. Very tender vegetables such as tomatoes and peppers are typically planted 2 or more weeks after the median last frost, and the earliest start is April 19[11].

  • Hardy (broccoli, cabbage, kohlrabi, lettuce, onions, peas, radishes, spinach, turnips): as early as 2 to 4 weeks before the median last frost (April 5) is March 8 to March 22[6]
  • Semi-hardy (beets, carrots, cauliflower, parsnips, potatoes, Swiss chard): as early as 2 weeks before the median last frost (April 5) is March 22, up to the median date itself[9]
  • Tender (snap beans, sweet corn, cucumbers, summer squash): from seed around the median last frost date, April 5[10]
  • Very tender (cantaloupe, eggplant, peppers, tomatoes, winter squash, watermelon): the earliest start, two weeks after the median last frost (April 5), is April 19[11]
Vegetable (CSU group) Plant from First harvest around
Broccoli (hardy)[12] Mar 8 May 12 (from transplants)
Cabbage (hardy)[12] Mar 8 Jun 1 (from transplants)
Kohlrabi (hardy)[12] Mar 8 Apr 27
Lettuce (hardy)[12] Mar 8 May 7
Onions (hardy)[12] Mar 8 Jun 26
Peas (hardy)[12] Mar 8 May 12
Radishes (hardy)[12] Mar 8 Apr 7
Spinach (hardy)[12] Mar 8 Apr 17
Turnips (hardy)[12] Mar 8 Apr 27
Beets (semi-hardy)[12] Mar 22 May 21
Carrots (semi-hardy)[12] Mar 22 May 31
Cauliflower (semi-hardy)[12] Mar 22 not listed
Parsnips (semi-hardy)[12] Mar 22 May 31
Potatoes (semi-hardy)[12] Mar 22 Jul 25
Swiss chard (semi-hardy)[12] Mar 22 May 21
Snap beans (tender)[12] Apr 5 Jun 4
Sweet corn (tender)[12] Apr 5 Jun 4
Cucumbers (tender)[12] Apr 5 May 30
Summer squash (tender)[12] Apr 5 May 25
Cantaloupe (very tender)[12] Apr 19 Jul 13
Eggplant (very tender)[12] Apr 19 Jun 18 (from transplants)
Peppers (very tender)[12] Apr 19 Jun 28 (from transplants)
Tomatoes (very tender)[12] Apr 19 Jun 23 (from transplants)
Winter squash (very tender)[12] Apr 19 Jul 28
Watermelon (very tender)[12] Apr 19 Jul 13
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 7a means the average coldest night of the year was 0°F to 5°F from 1991 to 2020[1]. The zone is based on winter lows, not on summer heat or frost dates[14]. By land area, 100% of the city lies in ZIP code areas rated zone 7a[15].

Zone 7a: average annual extreme minimum temperature 0°F to 5°F (1991 to 2020)[1]. Modeled value at the city center: 3.8°F[1].

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

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

Zone by ZIP code
ZIP code Zone Coldest night range
42101[15] 7a 0 to 5°F
42103[15] 7a 0 to 5°F
42104[15] 7a 0 to 5°F
42122[15] 7a 0 to 5°F

Questions people ask

What growing zone is Bowling Green, Kentucky?
The 2023 USDA map puts the center of Bowling Green in zone 7a[1]. By land area, 100% of the city lies in ZIP code areas rated zone 7a[15].
When is the last frost in Bowling Green?
The median last spring frost is April 5, so in half of years the last frost comes after that date[2]. In 1 of 10 years it comes after April 21[2].
When is the first frost in Bowling Green?
The median first fall frost is October 31, so in half of years the first frost comes before that date[3]. In 1 of 10 years it comes before October 20[3].
When to plant tomatoes in Bowling Green?
CSU Extension typically plants tomatoes 2 or more weeks after the average last spring frost, which makes April 19 the earliest start here[11]. CSU's guide was written for Colorado[11].
How long is the growing season in Bowling Green?
The growing season is at least 208 days in half of years[4]. It is at least 187 days in 9 of 10 years[4].

Facts and sources

  1. The 2023 USDA Plant Hardiness Zone Map puts the center of Bowling Green, Kentucky in zone 7a. Zone 7a means an average annual extreme minimum temperature of 0°F to 5°F over 1991 to 2020. The map's modeled value at the city center is 3.8°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 20, in half of years after April 5, and in 1 of 10 years after April 21 (NOAA 1991 to 2020 normals). The median last frost date is April 5. 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 October 31, and in 9 of 10 years before November 11 (NOAA 1991 to 2020 normals). The median first frost date is October 31. NOAA Climate Normals 1991-2020
  4. Growing season (days between the last spring and first fall 32°F frost) at this station: at least 187 days in 9 of 10 years, at least 208 days in half of years, and at least 229 days in 1 of 10 years. NOAA Climate Normals 1991-2020
  5. Frost dates on this page come from NOAA climate normals for the Bowling Green Warren County Airport weather station (USW00093808), 1 miles from the center of Bowling Green at 523 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 24 and the median first fall date is November 10. 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. Bowling Green, Kentucky overlaps 4 ZIP code areas. By land area, 100% 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.