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Frost dates and planting calendar for Alexandria, Virginia

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

USDA hardiness zone
8a[1]
Median last spring frost
Mar 24[2]
Median first fall frost
Nov 18[3]
Growing season, median
241 days[4]

The USDA map puts the center of Alexandria, Virginia in zone 8a[1]. NOAA records show the median last spring frost is March 24[2].

Frost dates

JanFebMarAprMayJunJulAugSepOctNovDecLast spring frost: 9 in 10 years after Mar 7, half of years Mar 24, 1 in 10 years after Apr 6Last frostmedian Mar 24First fall frost: 9 in 10 years before Dec 6, half of years Nov 18, 1 in 10 years before Nov 5First frostmedian Nov 18Frost riskHardyHardy vegetables: plant Feb 24 to Mar 10Feb 24 to Mar 10Semi-hardySemi-hardy vegetables: plant Mar 10 to Mar 24Mar 10 to Mar 24TenderTender vegetables: plant around Mar 24around Mar 24Very tenderVery tender vegetables: plant from Apr 7from Apr 7
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)[7]. Exact dates are in the tables below.

These frost dates come from NOAA climate normals for 1991 to 2020 at the Washington Reagan Airport weather station near Alexandria[5]. They are odds, not a forecast. In half of years the last spring frost comes after March 24[2]. In 1 of 10 years it comes after April 6[2]. In half of years the first fall frost comes before November 18, and in 1 of 10 years it comes before November 5[3]. At this station the low reached 32°F or colder in 100% of years[6]. Any year can be earlier or later than these dates.

Frost Likely (9 in 10 years) Even odds (5 in 10) Unlikely (1 in 10)
Last spring frost (32°F)[2] after March 7 after March 24 after April 6
First fall frost (32°F)[3] before November 5 before November 18 before December 6
  • Hard freeze (28°F): median last spring date March 12, median first fall date December 3[8].
  • Frost-free growing season: at least 220 days in 9 of 10 years, 241 days in half of years and 265 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[6].
  • Weather station: Washington Reagan Airport (USW00013743), 3.3 miles from the city center, 10 feet, 27 years of 1991 to 2020 records[5].

When to plant vegetables

Colorado State University Extension groups vegetables by how well they handle frost, and its guide was written for Colorado[7]. GardenFacts used the NOAA median last frost of March 24 as the average last frost[7]. Hardy vegetables such as broccoli, lettuce, peas and spinach can go in as early as 2 to 4 weeks before that date, which is February 24 to March 10[7]. Semi-hardy vegetables such as beets, carrots and potatoes can go in as early as 2 weeks before, which is March 10, up to the median date itself[9]. Snap beans, sweet corn, cucumbers and summer squash start from seed around March 24[10]. Tomatoes, peppers and eggplant are very tender. CSU says typically 2 or more weeks after the average last frost, and the earliest start is April 7[11]. These planting dates are a GardenFacts calculation from the CSU rules[7].

  • Hardy (broccoli, cabbage, kohlrabi, lettuce, onions, peas, radishes, spinach, turnips): as early as 2 to 4 weeks before the median last frost (March 24) is February 24 to March 10[7]
  • Semi-hardy (beets, carrots, cauliflower, parsnips, potatoes, Swiss chard): as early as 2 weeks before the median last frost (March 24) is March 10, up to the median date itself[9]
  • Tender (snap beans, sweet corn, cucumbers, summer squash): from seed around the median last frost date, March 24[10]
  • Very tender (cantaloupe, eggplant, peppers, tomatoes, winter squash, watermelon): the earliest start, two weeks after the median last frost (March 24), is April 7[11]
Vegetable (CSU group) Plant from First harvest around
Broccoli (hardy)[12] Feb 24 Apr 30 (from transplants)
Cabbage (hardy)[12] Feb 24 May 20 (from transplants)
Kohlrabi (hardy)[12] Feb 24 Apr 15
Lettuce (hardy)[12] Feb 24 Apr 25
Onions (hardy)[12] Feb 24 Jun 14
Peas (hardy)[12] Feb 24 Apr 30
Radishes (hardy)[12] Feb 24 Mar 26
Spinach (hardy)[12] Feb 24 Apr 5
Turnips (hardy)[12] Feb 24 Apr 15
Beets (semi-hardy)[12] Mar 10 May 9
Carrots (semi-hardy)[12] Mar 10 May 19
Cauliflower (semi-hardy)[12] Mar 10 not listed
Parsnips (semi-hardy)[12] Mar 10 May 19
Potatoes (semi-hardy)[12] Mar 10 Jul 13
Swiss chard (semi-hardy)[12] Mar 10 May 9
Snap beans (tender)[12] Mar 24 May 23
Sweet corn (tender)[12] Mar 24 May 23
Cucumbers (tender)[12] Mar 24 May 18
Summer squash (tender)[12] Mar 24 May 13
Cantaloupe (very tender)[12] Apr 7 Jul 1
Eggplant (very tender)[12] Apr 7 Jun 6 (from transplants)
Peppers (very tender)[12] Apr 7 Jun 16 (from transplants)
Tomatoes (very tender)[12] Apr 7 Jun 11 (from transplants)
Winter squash (very tender)[12] Apr 7 Jul 16
Watermelon (very tender)[12] Apr 7 Jul 1
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 8a means an average annual extreme minimum temperature of 10°F to 15°F over 1991 to 2020[1]. The zone is based on the coldest night of each winter. It is not based on summer heat or frost dates[14]. Alexandria is not all one zone. By land area, 58% lies in ZIP code areas rated zone 8a and 42% lies in areas rated zone 7b[15].

Zone 8a: average annual extreme minimum temperature 10°F to 15°F (1991 to 2020)[1]. Modeled value at the city center: 10.1°F[1].

Share of the city's land area by ZIP code zone: zone 8a 58%, zone 7b 42%[15].

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

Zone by ZIP code
ZIP code Zone Coldest night range
22304[15] 7b 5 to 10°F
22314[15] 8a 10 to 15°F
22302[15] 8a 10 to 15°F
22301[15] 8a 10 to 15°F
22305[15] 8a 10 to 15°F
22311[15] 7b 5 to 10°F
22312[15] 7b 5 to 10°F
22206[15] 8a 10 to 15°F

Questions people ask

What growing zone is Alexandria, Virginia?
The 2023 USDA map puts the center of Alexandria in zone 8a[1]. By land area, 58% of the city is in ZIP code areas rated 8a and 42% in areas rated 7b[15].
When is the last frost in Alexandria?
The median last spring frost is March 24, so in half of years the last frost comes after that date[2]. In 1 of 10 years it comes after April 6[2].
When is the first frost in Alexandria?
The median first fall frost is November 18[3]. In 1 of 10 years the first frost comes before November 5[3].
When to plant tomatoes in Alexandria?
CSU Extension says tomatoes are very tender and typically go in 2 or more weeks after the average last frost, which gives April 7 as the earliest start here[11]. CSU's guide was written for Colorado[11].
How long is the growing season in Alexandria?
The growing season between the last spring and first fall frost is at least 241 days in half of years[4]. It is at least 220 days in 9 of 10 years[4].

Facts and sources

  1. The 2023 USDA Plant Hardiness Zone Map puts the center of Alexandria, Virginia in zone 8a. Zone 8a means an average annual extreme minimum temperature of 10°F to 15°F over 1991 to 2020. The map's modeled value at the city center is 10.1°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 7, in half of years after March 24, and in 1 of 10 years after April 6 (NOAA 1991 to 2020 normals). The median last frost date is March 24. 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 5, in half of years before November 18, and in 9 of 10 years before December 6 (NOAA 1991 to 2020 normals). The median first frost date is November 18. NOAA Climate Normals 1991-2020
  4. Growing season (days between the last spring and first fall 32°F frost) at this station: at least 220 days in 9 of 10 years, at least 241 days in half of years, and at least 265 days in 1 of 10 years. NOAA Climate Normals 1991-2020
  5. Frost dates on this page come from NOAA climate normals for the Washington Reagan Airport weather station (USW00013743), 3.3 miles from the center of Alexandria at 10 feet, using 27 years of records from 1991 to 2020. NOAA Climate Normals 1991-2020
  6. 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
  7. 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
  8. Hard freeze (28°F) at this station: the median last spring date is March 12 and the median first fall date is December 3. 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. Alexandria, Virginia overlaps 8 ZIP code areas. By land area, 58% lies in ZIP code areas rated zone 8a, 42% 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.