US Grow Zones

USDA hardiness zone 8b

In zone 8b, the average annual extreme minimum temperature is 15 to 20°F (-9.4 to -6.7°C), based on 1991–2020 data from the 2023 USDA Plant Hardiness Zone Map.

Temperature range15 to 20°F-9.4 to -6.7°C
ZIP codes3,379in this half-zone
Major cities59on this site
Typical last frostMar 2230% risk

What zone 8b means for your garden

A plant labeled "hardy to zone 8b" should survive a typical winter low of 15°F. Most perennials sold at garden centers are rated for this zone or colder; marginal plants rated one zone warmer can survive in sheltered spots. Zone 8a is the colder half of zone 8.

ZIP codes in zone 8b: 3,375 in contiguous U.S., 4 in Alaska.

Frost dates in zone 8b

Across 59 major cities in zone 8b, the 30%-risk last spring frost ranges from Mar 6 to May 1 (median Mar 22), and the first fall frost has a median of Nov 10. Frost timing depends on elevation, latitude and distance from water — a zone does not set a frost date, so check your city page for local dates.

Typical planting calendar for zone 8b

Based on the median frost dates above. For your exact dates, use your city page.

CropStart indoorsTransplant / plant outDirect sowFall crop sow/plant
TomatoJan 25 – Feb 8Mar 29 – Apr 12——
PepperJan 11 – Jan 25Apr 5 – Apr 19——
LettuceFeb 8 – Feb 22Mar 8 – Mar 29Feb 22 – Apr 5Sep 1 – Sep 29
Green Beans——Mar 29 – May 3Aug 18 – Sep 1
Sweet Corn——Mar 29 – Apr 26—
Zucchini & Summer SquashFeb 22 – Mar 1Mar 29 – Apr 12Mar 29 – Apr 19Aug 18 – Sep 1
CucumberFeb 22 – Mar 1Apr 5 – Apr 12Mar 29 – Apr 19Aug 18 – Sep 1
Carrot——Mar 1 – Apr 5Aug 18 – Sep 1
OnionDec 28 – Jan 11Feb 22 – Mar 8——
Potato—Feb 22 – Mar 15——
BasilFeb 8 – Feb 22Apr 5 – Apr 19Apr 5 – Apr 26—
Spinach——Feb 8 – Mar 8Sep 15 – Oct 13
KaleJan 25 – Feb 8Feb 22 – Mar 15Feb 22 – Mar 15Sep 1 – Sep 29
BroccoliJan 25 – Feb 8Mar 8 – Mar 29—Aug 18 – Sep 1
Peas——Feb 8 – Mar 1Sep 1 – Sep 15
EggplantJan 11 – Jan 25Apr 5 – Apr 19——
CabbageJan 25 – Feb 8Feb 22 – Mar 8—Aug 18 – Sep 1
Radish——Feb 15 – Apr 5Sep 29 – Oct 27
Strawberry—Feb 22 – Mar 15——
Beets——Mar 1 – Apr 12Sep 1 – Sep 15

Cities in zone 8b (59)

Major cities whose center falls in zone 8b:

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