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Frost dates and planting calendar for Summerville, South Carolina

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 22[2]
Median first fall frost
Nov 12[3]
Growing season, median
238 days[4]

The USDA 2023 map puts the center of Summerville, South Carolina in zone 8b[1]. The median last spring frost here is March 22, so in half of years the last frost comes after that date[2].

Frost dates

JanFebMarAprMayJunJulAugSepOctNovDecLast spring frost: 9 in 10 years after Mar 1, half of years Mar 22, 1 in 10 years after Apr 7Last frostmedian Mar 22First fall frost: 9 in 10 years before Dec 3, half of years Nov 12, 1 in 10 years before Oct 29First frostmedian Nov 12Frost riskHardyHardy vegetables: plant Feb 22 to Mar 8Feb 22 to Mar 8Semi-hardySemi-hardy vegetables: plant Mar 8 to Mar 22Mar 8 to Mar 22TenderTender vegetables: plant around Mar 22around Mar 22Very tenderVery tender vegetables: plant from Apr 5from Apr 5
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 frost dates for Summerville come from the Summerville 4W weather station, using 1991 to 2020 records[5]. In 9 of 10 years the last spring frost comes after March 1, and in 1 of 10 years it comes after April 7[2]. In the fall, the first frost comes before November 12 in half of years, and before October 29 in 1 of 10 years[3]. These are chances from past records, not a forecast, so any year can be earlier or later[2][3].

Frost Likely (9 in 10 years) Even odds (5 in 10) Unlikely (1 in 10)
Last spring frost (32°F)[2] after March 1 after March 22 after April 7
First fall frost (32°F)[3] before October 29 before November 12 before December 3
  • Hard freeze (28°F): median last spring date March 7, median first fall date November 29[7].
  • Frost-free growing season: at least 213 days in 9 of 10 years, 238 days in half of years and 266 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: Summerville 4W (USC00388426), 3.7 miles from the city center, 65 feet, 22 years of 1991 to 2020 records[5].

When to plant vegetables

Colorado State University Extension's planting guide was written 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 is February 22 to March 8[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 8[9]. Tender vegetables such as snap beans and sweet corn go in from seed around March 22[10]. Very tender vegetables such as tomatoes and peppers typically wait 2 or more weeks after the median last frost, so the earliest start is April 5[11].

  • Hardy (broccoli, cabbage, kohlrabi, lettuce, onions, peas, radishes, spinach, turnips): as early as 2 to 4 weeks before the median last frost (March 22) is February 22 to March 8[6]
  • Semi-hardy (beets, carrots, cauliflower, parsnips, potatoes, Swiss chard): as early as 2 weeks before the median last frost (March 22) is March 8, up to the median date itself[9]
  • Tender (snap beans, sweet corn, cucumbers, summer squash): from seed around the median last frost date, March 22[10]
  • Very tender (cantaloupe, eggplant, peppers, tomatoes, winter squash, watermelon): the earliest start, two weeks after the median last frost (March 22), is April 5[11]
Vegetable (CSU group) Plant from First harvest around
Broccoli (hardy)[12] Feb 22 Apr 28 (from transplants)
Cabbage (hardy)[12] Feb 22 May 18 (from transplants)
Kohlrabi (hardy)[12] Feb 22 Apr 13
Lettuce (hardy)[12] Feb 22 Apr 23
Onions (hardy)[12] Feb 22 Jun 12
Peas (hardy)[12] Feb 22 Apr 28
Radishes (hardy)[12] Feb 22 Mar 24
Spinach (hardy)[12] Feb 22 Apr 3
Turnips (hardy)[12] Feb 22 Apr 13
Beets (semi-hardy)[12] Mar 8 May 7
Carrots (semi-hardy)[12] Mar 8 May 17
Cauliflower (semi-hardy)[12] Mar 8 not listed
Parsnips (semi-hardy)[12] Mar 8 May 17
Potatoes (semi-hardy)[12] Mar 8 Jul 11
Swiss chard (semi-hardy)[12] Mar 8 May 7
Snap beans (tender)[12] Mar 22 May 21
Sweet corn (tender)[12] Mar 22 May 21
Cucumbers (tender)[12] Mar 22 May 16
Summer squash (tender)[12] Mar 22 May 11
Cantaloupe (very tender)[12] Apr 5 Jun 29
Eggplant (very tender)[12] Apr 5 Jun 4 (from transplants)
Peppers (very tender)[12] Apr 5 Jun 14 (from transplants)
Tomatoes (very tender)[12] Apr 5 Jun 9 (from transplants)
Winter squash (very tender)[12] Apr 5 Jul 14
Watermelon (very tender)[12] Apr 5 Jun 29
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 winter 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]. All of Summerville's land area, across 5 ZIP code areas, lies in ZIP code areas rated zone 8b[15].

Zone 8b: average annual extreme minimum temperature 15°F to 20°F (1991 to 2020)[1]. Modeled value at the city center: 18.8°F[1].

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

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

Zone by ZIP code
ZIP code Zone Coldest night range
29483[15] 8b 15 to 20°F
29485[15] 8b 15 to 20°F
29456[15] 8b 15 to 20°F
29486[15] 8b 15 to 20°F
29414[15] 9a 20 to 25°F

Questions people ask

What growing zone is Summerville, South Carolina?
The center of Summerville is in USDA zone 8b on the 2023 map[1]. By land area, 100% of the city lies in ZIP code areas rated 8b[15].
When is the last frost in Summerville?
The median last spring frost is March 22, so in half of years the last frost comes after that date[2]. In 1 of 10 years it comes after April 7[2].
When to plant tomatoes in Summerville?
CSU Extension says very tender vegetables like tomatoes typically go in 2 or more weeks after the average last frost[11]. Using the median last frost, the earliest start is April 5[11].
When is the first frost in Summerville?
The median first fall frost is November 12, so in half of years the first frost comes before that date[3]. In 1 of 10 years it comes before October 29[3].
How long is the growing season in Summerville?
In half of years the growing season is at least 238 days[4]. In 9 of 10 years it is at least 213 days[4].

Facts and sources

  1. The 2023 USDA Plant Hardiness Zone Map puts the center of Summerville, South Carolina 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 18.8°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 1, in half of years after March 22, and in 1 of 10 years after April 7 (NOAA 1991 to 2020 normals). The median last frost date is March 22. 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 29, in half of years before November 12, and in 9 of 10 years before December 3 (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 213 days in 9 of 10 years, at least 238 days in half of years, and at least 266 days in 1 of 10 years. NOAA Climate Normals 1991-2020
  5. Frost dates on this page come from NOAA climate normals for the Summerville 4W weather station (USC00388426), 3.7 miles from the center of Summerville at 65 feet, using 22 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 7 and the median first fall date is November 29. 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. Summerville, South Carolina overlaps 5 ZIP code areas. By land area, 100% lies in ZIP code areas rated zone 8b. 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.