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Frost dates and planting calendar for McDonough, Georgia

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 25[2]
Median first fall frost
Nov 12[3]
Growing season, median
235 days[4]

The USDA 2023 map puts the center of McDonough, Georgia in zone 8b[1]. In half of years the last spring frost comes after March 25, which is the median[2].

Frost dates

JanFebMarAprMayJunJulAugSepOctNovDecLast spring frost: 9 in 10 years after Mar 2, half of years Mar 25, 1 in 10 years after Apr 10Last frostmedian Mar 25First fall frost: 9 in 10 years before Dec 2, half of years Nov 12, 1 in 10 years before Oct 31First frostmedian Nov 12Frost riskHardyHardy vegetables: plant Feb 25 to Mar 11Feb 25 to Mar 11Semi-hardySemi-hardy vegetables: plant Mar 11 to Mar 25Mar 11 to Mar 25TenderTender vegetables: plant around Mar 25around Mar 25Very tenderVery tender vegetables: plant from Apr 8from Apr 8
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 Jonesboro weather station, using records from 1991 to 2020[5]. In 9 of 10 years the last spring frost comes after March 2, and in 1 of 10 years it comes after April 10[2]. In the fall, the median first frost is November 12[3]. In 1 of 10 years the first frost comes before October 31[3].

Frost Likely (9 in 10 years) Even odds (5 in 10) Unlikely (1 in 10)
Last spring frost (32°F)[2] after March 2 after March 25 after April 10
First fall frost (32°F)[3] before October 31 before November 12 before December 2
  • Hard freeze (28°F): median last spring date March 8, median first fall date November 28[7].
  • Frost-free growing season: at least 211 days in 9 of 10 years, 235 days in half of years and 263 days in 1 of 10 years[4].
  • The low reached 32°F or colder in 100% of years and 28°F or colder in 99.9% of years[8].
  • Weather station: Jonesboro (USC00094700), 13.2 miles from the city center, 930 feet, 20 years of 1991 to 2020 records[5].

When to plant vegetables

Colorado State University Extension wrote its planting guide for Colorado[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 February 25 to March 11[6]. Semi-hardy vegetables such as carrots and potatoes can go in as early as 2 weeks before the median last frost, which is March 11[9]. Tender vegetables such as snap beans and sweet corn can be planted from seed around March 25[10]. Very tender vegetables such as tomatoes and peppers typically go in 2 or more weeks after the median last frost, so April 8 is the earliest start[11].

  • Hardy (broccoli, cabbage, kohlrabi, lettuce, onions, peas, radishes, spinach, turnips): as early as 2 to 4 weeks before the median last frost (March 25) is February 25 to March 11[6]
  • Semi-hardy (beets, carrots, cauliflower, parsnips, potatoes, Swiss chard): as early as 2 weeks before the median last frost (March 25) is March 11, up to the median date itself[9]
  • Tender (snap beans, sweet corn, cucumbers, summer squash): from seed around the median last frost date, March 25[10]
  • Very tender (cantaloupe, eggplant, peppers, tomatoes, winter squash, watermelon): the earliest start, two weeks after the median last frost (March 25), is April 8[11]
Vegetable (CSU group) Plant from First harvest around
Broccoli (hardy)[12] Feb 25 May 1 (from transplants)
Cabbage (hardy)[12] Feb 25 May 21 (from transplants)
Kohlrabi (hardy)[12] Feb 25 Apr 16
Lettuce (hardy)[12] Feb 25 Apr 26
Onions (hardy)[12] Feb 25 Jun 15
Peas (hardy)[12] Feb 25 May 1
Radishes (hardy)[12] Feb 25 Mar 27
Spinach (hardy)[12] Feb 25 Apr 6
Turnips (hardy)[12] Feb 25 Apr 16
Beets (semi-hardy)[12] Mar 11 May 10
Carrots (semi-hardy)[12] Mar 11 May 20
Cauliflower (semi-hardy)[12] Mar 11 not listed
Parsnips (semi-hardy)[12] Mar 11 May 20
Potatoes (semi-hardy)[12] Mar 11 Jul 14
Swiss chard (semi-hardy)[12] Mar 11 May 10
Snap beans (tender)[12] Mar 25 May 24
Sweet corn (tender)[12] Mar 25 May 24
Cucumbers (tender)[12] Mar 25 May 19
Summer squash (tender)[12] Mar 25 May 14
Cantaloupe (very tender)[12] Apr 8 Jul 2
Eggplant (very tender)[12] Apr 8 Jun 7 (from transplants)
Peppers (very tender)[12] Apr 8 Jun 17 (from transplants)
Tomatoes (very tender)[12] Apr 8 Jun 12 (from transplants)
Winter squash (very tender)[12] Apr 8 Jul 17
Watermelon (very tender)[12] Apr 8 Jul 2
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 an average coldest night of the year between 15°F and 20°F over 1991 to 2020[1]. The zone is based on winter lows, not on summer heat or frost dates[14]. The map's value at the city center is 8b, but the 2 ZIP code areas that overlap McDonough are rated zone 8a, so the city is not all one zone[1][15].

Zone 8b: average annual extreme minimum temperature 15°F to 20°F (1991 to 2020)[1]. Modeled value at the city center: 15.1°F[1].

Share of the city's land area by ZIP code zone: zone 8a 100%[15].

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

Zone by ZIP code
ZIP code Zone Coldest night range
30253[15] 8a 10 to 15°F
30252[15] 8a 10 to 15°F

Questions people ask

What growing zone is McDonough, Georgia?
The center of McDonough is in USDA zone 8b on the 2023 map[1]. Both ZIP code areas that overlap the city are rated 8a[15].
When is the last frost in McDonough?
The median last spring frost is March 25, so in half of years the last frost comes after that date[2]. In 1 of 10 years it comes after April 10[2].
When to plant tomatoes in McDonough?
CSU Extension puts tomatoes with the very tender vegetables, which typically go in 2 or more weeks after the average last frost[11]. Using the median last frost, the earliest start is April 8[11].
When is the first frost in McDonough?
The median first fall frost is November 12[3]. In 1 of 10 years the first frost comes before October 31[3].
How long is the growing season in McDonough?
The growing season is at least 235 days in half of years[4]. It is at least 211 days in 9 of 10 years[4].

Facts and sources

  1. The 2023 USDA Plant Hardiness Zone Map puts the center of McDonough, Georgia 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 15.1°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 2, in half of years after March 25, and in 1 of 10 years after April 10 (NOAA 1991 to 2020 normals). The median last frost date is March 25. 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 31, in half of years before November 12, and in 9 of 10 years before December 2 (NOAA 1991 to 2020 normals). The median first frost date is November 12. NOAA Climate Normals 1991-2020
  4. Growing season (days between the last spring and first fall 32°F frost) at this station: at least 211 days in 9 of 10 years, at least 235 days in half of years, and at least 263 days in 1 of 10 years. NOAA Climate Normals 1991-2020
  5. Frost dates on this page come from NOAA climate normals for the Jonesboro weather station (USC00094700), 13.2 miles from the center of McDonough at 930 feet, using 20 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 8 and the median first fall date is November 28. 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 99.9% 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. McDonough, Georgia overlaps 2 ZIP code areas. By land area, 100% 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.