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Frost dates and planting calendar for Denton, Texas

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

USDA hardiness zone
8b[1]
Median last spring frost
Mar 13[2]
Median first fall frost
Nov 20[3]
Growing season, median
251 days[4]

The USDA map puts the center of Denton in zone 8b[1]. NOAA records show the median last spring frost is March 13[2].

Frost dates

JanFebMarAprMayJunJulAugSepOctNovDecLast spring frost: 9 in 10 years after Feb 24, half of years Mar 13, 1 in 10 years after Mar 31Last frostmedian Mar 13First fall frost: 9 in 10 years before Dec 8, half of years Nov 20, 1 in 10 years before Nov 3First frostmedian Nov 20Frost riskHardyHardy vegetables: plant Feb 13 to Feb 27Feb 13 to Feb 27Semi-hardySemi-hardy vegetables: plant Feb 27 to Mar 13Feb 27 to Mar 13TenderTender vegetables: plant around Mar 13around Mar 13Very tenderVery tender vegetables: plant from Mar 27from Mar 27
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 dates come from NOAA climate normals for the Denton 2SE weather station, using records from 1991 to 2020[5]. In half of years the last spring frost comes after March 13, and in 1 of 10 years it comes after March 31[2]. In 9 of 10 years the last frost comes after February 24[2]. In the fall, the median first frost is November 20, and in 1 of 10 years it comes before November 3[3]. These are odds from past years, 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 February 24 after March 13 after March 31
First fall frost (32°F)[3] before November 3 before November 20 before December 8
  • Hard freeze (28°F): median last spring date March 1, median first fall date December 1[7].
  • Frost-free growing season: at least 226 days in 9 of 10 years, 251 days in half of years and 278 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: Denton 2SE (USC00412404), 2.5 miles from the city center, 630 feet, 27 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]. 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 February 13 to February 27 in Denton[6]. Semi-hardy vegetables such as carrots and potatoes can go in as early as 2 weeks before the median last frost, which is February 27[9]. Tender vegetables such as snap beans and sweet corn can be planted from seed around March 13[10]. Very tender vegetables such as tomatoes and peppers typically start 2 or more weeks after the median last frost, so the earliest start is March 27[11].

  • Hardy (broccoli, cabbage, kohlrabi, lettuce, onions, peas, radishes, spinach, turnips): as early as 2 to 4 weeks before the median last frost (March 13) is February 13 to February 27[6]
  • Semi-hardy (beets, carrots, cauliflower, parsnips, potatoes, Swiss chard): as early as 2 weeks before the median last frost (March 13) is February 27, up to the median date itself[9]
  • Tender (snap beans, sweet corn, cucumbers, summer squash): from seed around the median last frost date, March 13[10]
  • Very tender (cantaloupe, eggplant, peppers, tomatoes, winter squash, watermelon): the earliest start, two weeks after the median last frost (March 13), is March 27[11]
Vegetable (CSU group) Plant from First harvest around
Broccoli (hardy)[12] Feb 13 Apr 19 (from transplants)
Cabbage (hardy)[12] Feb 13 May 9 (from transplants)
Kohlrabi (hardy)[12] Feb 13 Apr 4
Lettuce (hardy)[12] Feb 13 Apr 14
Onions (hardy)[12] Feb 13 Jun 3
Peas (hardy)[12] Feb 13 Apr 19
Radishes (hardy)[12] Feb 13 Mar 15
Spinach (hardy)[12] Feb 13 Mar 25
Turnips (hardy)[12] Feb 13 Apr 4
Beets (semi-hardy)[12] Feb 27 Apr 28
Carrots (semi-hardy)[12] Feb 27 May 8
Cauliflower (semi-hardy)[12] Feb 27 not listed
Parsnips (semi-hardy)[12] Feb 27 May 8
Potatoes (semi-hardy)[12] Feb 27 Jul 2
Swiss chard (semi-hardy)[12] Feb 27 Apr 28
Snap beans (tender)[12] Mar 13 May 12
Sweet corn (tender)[12] Mar 13 May 12
Cucumbers (tender)[12] Mar 13 May 7
Summer squash (tender)[12] Mar 13 May 2
Cantaloupe (very tender)[12] Mar 27 Jun 20
Eggplant (very tender)[12] Mar 27 May 26 (from transplants)
Peppers (very tender)[12] Mar 27 Jun 5 (from transplants)
Tomatoes (very tender)[12] Mar 27 May 31 (from transplants)
Winter squash (very tender)[12] Mar 27 Jul 5
Watermelon (very tender)[12] Mar 27 Jun 20
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 8b means the average coldest night of the winter is 15°F to 20°F, based on 1991 to 2020[1]. The zone is about winter cold, not summer heat or frost dates[14]. Denton overlaps 13 ZIP code areas[15]. By land area, half lies in zone 8b areas and half in zone 8a areas[15].

Zone 8b: average annual extreme minimum temperature 15°F to 20°F (1991 to 2020)[1]. Modeled value at the city center: 15.2°F[1].

Share of the city's land area by ZIP code zone: zone 8b 50%, zone 8a 50%[15].

All towns in zone 8b and what zone 8b means

Zone by ZIP code
ZIP code Zone Coldest night range
76207[15] 8a 10 to 15°F
76208[15] 8b 15 to 20°F
76205[15] 8b 15 to 20°F
76210[15] 8b 15 to 20°F
76209[15] 8b 15 to 20°F
76227[15] 8b 15 to 20°F
76201[15] 8a 10 to 15°F
76226[15] 8b 15 to 20°F
76266[15] 8a 10 to 15°F
76259[15] 8a 10 to 15°F
76249[15] 8a 10 to 15°F
76258[15] 8a 10 to 15°F
76203[15] 8a 10 to 15°F

Questions people ask

What growing zone is Denton, Texas?
The 2023 USDA map puts the center of Denton in zone 8b[1]. By land area, half of the city is in zone 8b ZIP code areas and half in zone 8a[15].
When is the last frost in Denton?
The median last spring frost is March 13[2]. In 1 of 10 years the last frost comes after March 31[2].
When to plant tomatoes in Denton?
CSU Extension typically starts tomatoes 2 or more weeks after the average last frost, which makes March 27 the earliest start in Denton[11]. That guide was written for Colorado[11].
When is the first frost in Denton?
The median first fall frost is November 20[3]. In 1 of 10 years it comes before November 3[3].
How long is the growing season in Denton?
In half of years the season between the last and first frost is at least 251 days[4]. In 9 of 10 years it is at least 226 days[4].

Facts and sources

  1. The 2023 USDA Plant Hardiness Zone Map puts the center of Denton, Texas in zone 8b. Zone 8b means an average annual extreme minimum temperature of 15°F to 20°F over 1991 to 2020. The map's modeled value at the city center is 15.2°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 February 24, in half of years after March 13, and in 1 of 10 years after March 31 (NOAA 1991 to 2020 normals). The median last frost date is March 13. NOAA Climate Normals 1991-2020
  3. First fall frost (32°F) at this station: in 1 of 10 years the first frost comes before November 3, in half of years before November 20, and in 9 of 10 years before December 8 (NOAA 1991 to 2020 normals). The median first frost date is November 20. NOAA Climate Normals 1991-2020
  4. Growing season (days between the last spring and first fall 32°F frost) at this station: at least 226 days in 9 of 10 years, at least 251 days in half of years, and at least 278 days in 1 of 10 years. NOAA Climate Normals 1991-2020
  5. Frost dates on this page come from NOAA climate normals for the Denton 2SE weather station (USC00412404), 2.5 miles from the center of Denton at 630 feet, using 27 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 1 and the median first fall date is December 1. 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. Denton, Texas overlaps 13 ZIP code areas. By land area, 50% lies in ZIP code areas rated zone 8b, 50% lies in ZIP code areas rated zone 8a. 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.