PlantAlong

When to plant peppers in zone 6b

Transplant outdoors around May 6. That is 2 weeks after zone 6b's median last frost, Apr 221. Across most of zone 6b that date falls between Apr 24 and May 17.

Why a range: zone 6b is defined by winter lows, not frost dates. Its ZIP codes have median last frosts from Apr 10 to May 32, so a single zone date can be weeks off for you. The rule comes from Colorado State University Extension, written for CO and applied here to zone 6b's frost dates.

Last reviewed
Stations
899
ZIP codes
4,372
Photo: Yan Krukau / Pexels
These dates use the typical last frost for the whole zone. Your ZIP code gives a closer answer.
  1. Start indoorsOregon State, central OR
  2. Transplant outdoorsColorado State
  • Start indoors
  • Plant outdoors
  • Range across the zone
  • Frost-free season (median)
  • Spring frost risk (90% to 10%)
  • Fall frost risk (10% to 90%)
Figure 1. Peppers in zone 6b. Dark bars: at the zone's median frost dates. Pale bars: across most of the zone's ZIP codes. Hatched blue: where the zone's last and first frosts fall.
Start seeds indoors
Mar 116 weeks before last frost (Oregon State, central OR)
Transplant outdoors
May 6range Apr 24 – May 17
First harvest, roughly
Jul 1570 days from transplant1

Five digits. The calendar is computed on your device.

What each source says, applied to zone 6b

The same frost dates give different answers depending on whose rule you follow. These are all the published rules we hold for peppers, worked out at zone 6b's median frost dates.

Table 1. Peppers rules from every source, at zone 6b's median last frost (Apr 22) and first frost (Oct 22).
SourceWhatRuleZone 6b median
Colorado State1Used aboveTransplant outdoors2 weeks after last frostMay 6
Utah State3Transplant outdoors2 weeks after last frostMay 6
Oregon State, central OR4Transplant outdoors2 weeks after last frostMay 6
Oregon State, central OR4Used aboveStart indoors6 weeks before last frostMar 11
Texas A&M (E-502)5Transplant outdoors1-8 weeks after last frostApr 29 – Jun 17
Texas A&M (E-502)5Plant for fall12-16 weeks before first frostJul 2 – Jul 30

Frost across zone 6b

  1. Last spring frostmedian Apr 22
  2. First fall frostmedian Oct 22
  • Frost-free season (median)
Figure 2. Frost dates across zone 6b, from 899 NOAA stations matched to 4,372 ZIP codes.

Sources

  1. Colorado State University Extension, Vegetable Planting Guide (CMG GardenNotes #720), reviewed September 2024. Retrieved 2026-11-02.
  2. NOAA National Centers for Environmental Information, U.S. Climate Normals 2020: U.S. Annual/Seasonal Climate Normals (1991-2020), 2021. Retrieved 2026-11-02.
  3. Utah State University Extension, Suggested Vegetable Planting Dates for Utah, January 2018; revised May 2025. Retrieved 2026-11-02.
  4. Oregon State University Extension Service, When to start seeds indoors in central Oregon, reviewed 2024. Retrieved 2026-11-02.
  5. Texas AgriLife Extension Service, The Texas A&M System, Texas Home Vegetable Gardening Guide (E-502), 2/09. Retrieved 2026-11-02.