PlantAlong

When to plant beans in zone 7a

Transplant outdoors around Apr 23. That is 1 weeks after zone 7a's median last frost, Apr 161. Across most of zone 7a that date falls between Apr 11 and May 5.

Why a range: zone 7a is defined by winter lows, not frost dates. Its ZIP codes have median last frosts from Apr 4 to Apr 282, so a single zone date can be weeks off for you. The rule comes from Oregon State University Extension Service.

Last reviewed
Stations
865
ZIP codes
3,807
Photo: Gobral / 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 outdoorsOregon State, central OR
  3. Sow 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. Beans in zone 7a. 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 263 weeks before last frost (Oregon State, central OR)
Transplant outdoors
Apr 23range Apr 11 – May 5

Five digits. The calendar is computed on your device.

What each source says, applied to zone 7a

The same frost dates give different answers depending on whose rule you follow. These are all the published rules we hold for beans, worked out at zone 7a's median frost dates.

Table 1. Beans rules from every source, at zone 7a's median last frost (Apr 16) and first frost (Oct 25).
SourceWhatRuleZone 7a median
Colorado State3Used aboveSow outdoorsOn the last frostApr 16
Utah State4Sow outdoorsOn the last frostApr 16
Oregon State, central OR1Used aboveTransplant outdoors1 weeks after last frostApr 23
Oregon State, central OR1Used aboveStart indoors3 weeks before last frostMar 26
Texas A&M (E-502)5Sow outdoors1-4 weeks after last frostApr 23 – May 14
Texas A&M (E-502)5Plant for fall8-10 weeks before first frostAug 16 – Aug 30
Texas A&M (E-502)5Plant for fall14-16 weeks before first frostJul 5 – Jul 19

Frost across zone 7a

  1. Last spring frostmedian Apr 16
  2. First fall frostmedian Oct 25
  • Frost-free season (median)
Figure 2. Frost dates across zone 7a, from 865 NOAA stations matched to 3,807 ZIP codes.

Sources

  1. Oregon State University Extension Service, When to start seeds indoors in central Oregon, reviewed 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. Colorado State University Extension, Vegetable Planting Guide (CMG GardenNotes #720), reviewed September 2024. Retrieved 2026-11-02.
  4. Utah State University Extension, Suggested Vegetable Planting Dates for Utah, January 2018; revised May 2025. 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.