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Frost dates and planting calendar for Medford, Oregon

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
Apr 8[2]
Median first fall frost
Oct 29[3]
Growing season, median
204 days[4]

The center of Medford, Oregon is in USDA hardiness zone 8b[1]. In half of years the last spring frost comes after April 8, the median date[2].

Frost dates

JanFebMarAprMayJunJulAugSepOctNovDecLast spring frost: 9 in 10 years after Mar 17, half of years Apr 8, 1 in 10 years after Apr 30Last frostmedian Apr 8First fall frost: 9 in 10 years before Nov 16, half of years Oct 29, 1 in 10 years before Oct 14First frostmedian Oct 29Frost riskHardyHardy vegetables: plant Mar 11 to Mar 25Mar 11 to Mar 25Semi-hardySemi-hardy vegetables: plant Mar 25 to Apr 8Mar 25 to Apr 8TenderTender vegetables: plant around Apr 8around Apr 8Very tenderVery tender vegetables: plant from Apr 22from Apr 22
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 Medford Rogue Vly Airport station, using records from 1991 to 2020[5]. In half of years the last spring frost comes after April 8, and in 1 of 10 years it comes after April 30[2]. In 9 of 10 years it comes after March 17[2]. In the fall, the first frost comes before October 29 in half of years, and before November 16 in 9 of 10 years[3]. These are odds from past years, not a forecast, so any year can be earlier or later[5].

Frost Likely (9 in 10 years) Even odds (5 in 10) Unlikely (1 in 10)
Last spring frost (32°F)[2] after March 17 after April 8 after April 30
First fall frost (32°F)[3] before October 14 before October 29 before November 16
  • Hard freeze (28°F): median last spring date March 10, median first fall date November 13[7].
  • Frost-free growing season: at least 176 days in 9 of 10 years, 204 days in half of years and 232 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: Medford Rogue Vly Airport (USW00024225), 3.3 miles from the city center, 1,297 feet, 26 years of 1991 to 2020 records[5].

When to plant vegetables

Colorado State University Extension groups vegetables by how well they handle frost. Its guide was written for Colorado[6]. The GardenFacts calculation uses the NOAA median last frost, April 8, as the average last frost[6]. Hardy vegetables such as broccoli, lettuce, peas and spinach can go in as early as 2 to 4 weeks before that date, which is March 11 to March 25[6]. Semi-hardy vegetables such as beets, carrots and potatoes can go in as early as 2 weeks before it, March 25, up to the median date itself[9]. Very tender vegetables such as tomatoes and peppers typically wait 2 or more weeks after it, and April 22 is the earliest start[10].

  • Hardy (broccoli, cabbage, kohlrabi, lettuce, onions, peas, radishes, spinach, turnips): as early as 2 to 4 weeks before the median last frost (April 8) is March 11 to March 25[6]
  • Semi-hardy (beets, carrots, cauliflower, parsnips, potatoes, Swiss chard): as early as 2 weeks before the median last frost (April 8) is March 25, up to the median date itself[9]
  • Tender (snap beans, sweet corn, cucumbers, summer squash): from seed around the median last frost date, April 8[11]
  • Very tender (cantaloupe, eggplant, peppers, tomatoes, winter squash, watermelon): the earliest start, two weeks after the median last frost (April 8), is April 22[10]
Vegetable (CSU group) Plant from First harvest around
Broccoli (hardy)[12] Mar 11 May 15 (from transplants)
Cabbage (hardy)[12] Mar 11 Jun 4 (from transplants)
Kohlrabi (hardy)[12] Mar 11 Apr 30
Lettuce (hardy)[12] Mar 11 May 10
Onions (hardy)[12] Mar 11 Jun 29
Peas (hardy)[12] Mar 11 May 15
Radishes (hardy)[12] Mar 11 Apr 10
Spinach (hardy)[12] Mar 11 Apr 20
Turnips (hardy)[12] Mar 11 Apr 30
Beets (semi-hardy)[12] Mar 25 May 24
Carrots (semi-hardy)[12] Mar 25 Jun 3
Cauliflower (semi-hardy)[12] Mar 25 not listed
Parsnips (semi-hardy)[12] Mar 25 Jun 3
Potatoes (semi-hardy)[12] Mar 25 Jul 28
Swiss chard (semi-hardy)[12] Mar 25 May 24
Snap beans (tender)[12] Apr 8 Jun 7
Sweet corn (tender)[12] Apr 8 Jun 7
Cucumbers (tender)[12] Apr 8 Jun 2
Summer squash (tender)[12] Apr 8 May 28
Cantaloupe (very tender)[12] Apr 22 Jul 16
Eggplant (very tender)[12] Apr 22 Jun 21 (from transplants)
Peppers (very tender)[12] Apr 22 Jul 1 (from transplants)
Tomatoes (very tender)[12] Apr 22 Jun 26 (from transplants)
Winter squash (very tender)[12] Apr 22 Jul 31
Watermelon (very tender)[12] Apr 22 Jul 16
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

The 2023 USDA map puts the center of Medford in zone 8b, which means an average yearly coldest night of 15°F to 20°F[1]. The zone is based on the coldest winter night, not on summer heat or frost dates[14]. Medford overlaps 3 ZIP code areas, and by land area 100% of the city lies in 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: 16.3°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
97504[15] 8b 15 to 20°F
97501[15] 8b 15 to 20°F
97502[15] 8b 15 to 20°F

Questions people ask

What growing zone is Medford, Oregon?
The center of Medford is in USDA zone 8b on the 2023 map[1]. All of the city's land area lies in ZIP code areas rated 8b[15].
When is the last frost in Medford?
The median last spring frost is April 8, so in half of years the last frost comes after that date[2]. In 1 of 10 years it comes after April 30[2].
When is the first frost in Medford?
The median first fall frost is October 29, so in half of years the first frost comes before that date[3]. In 1 of 10 years it comes before October 14[3].
When to plant tomatoes in Medford?
CSU Extension says tomatoes are very tender and typically go in 2 or more weeks after the average last frost[10]. Using the median last frost of April 8, the earliest start is April 22[10].
How long is the growing season in Medford?
In half of years the season between the last spring and first fall frost is at least 204 days[4]. In 9 of 10 years it is at least 176 days[4].

Facts and sources

  1. The 2023 USDA Plant Hardiness Zone Map puts the center of Medford, Oregon 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 16.3°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 17, in half of years after April 8, and in 1 of 10 years after April 30 (NOAA 1991 to 2020 normals). The median last frost date is April 8. 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 14, in half of years before October 29, and in 9 of 10 years before November 16 (NOAA 1991 to 2020 normals). The median first frost date is October 29. NOAA Climate Normals 1991-2020
  4. Growing season (days between the last spring and first fall 32°F frost) at this station: at least 176 days in 9 of 10 years, at least 204 days in half of years, and at least 232 days in 1 of 10 years. NOAA Climate Normals 1991-2020
  5. Frost dates on this page come from NOAA climate normals for the Medford Rogue Vly Airport weather station (USW00024225), 3.3 miles from the center of Medford at 1,297 feet, using 26 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 10 and the median first fall date is November 13. 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 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
  11. 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
  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. Medford, Oregon overlaps 3 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.