Hardiness zone

Zone 10b

The coldest winter night here averages 35 to 40°F1. Frost dates vary more than that suggests.

ZIP codes: 752
Weather stations: 34
Last reviewed: 2026-11-02

Photo: Alexander Aubin / Pexels

Your zone tells you how cold winter gets. It does not tell you when to plant.

Typical last frost: Jan 16most ZIPs Jan 4 – Jan 24
Typical first frost: Jan 13most ZIPs Dec 25 – Jan 17
Spread in spring: 20 daysbetween early and late ZIPs

Last spring frostmedian Jan 16Full range across the zone: Dec 29 to Feb 16Most of the zone (10th to 90th percentile): Jan 4 to Jan 24Zone median: Jan 16
First fall frostmedian Jan 13Full range across the zone: Dec 8 to Jan 30Most of the zone (10th to 90th percentile): Dec 25 to Jan 17Zone median: Jan 13

Frost-free season (median)

Figure 1. When frosts fall across zone 10b: the full range (pale), most ZIP codes (10th to 90th percentile, solid) and the median (marker). From 34 NOAA stations matched to 162 ZIP codes.

Zone and frost date are different things. The zone comes from the coldest winter night; frost dates come from spring and fall temperatures at weather stations2. Your own dates can sit anywhere in the range above, so the calendar for your ZIP is the better guide.

When to plant in zone 10b

Each crop uses its primary extension source, applied to this zone's frost spread. Rules written for another state are labelled with their source.

TomatoesStart indoors across most of the zone: Nov 9 to Nov 29Start indoors at the zone median: Nov 21 (Oregon State, central OR)Transplant outdoors across most of the zone: Jan 18 to Feb 7Transplant outdoors at the zone median: Jan 30 (Colorado State)Plant for fall across most of the zone: Sep 18 to Oct 25Plant for fall at the zone median: Oct 7 to Oct 21 (Texas A&M (E-502))
PeppersStart indoors across most of the zone: Nov 23 to Dec 13Start indoors at the zone median: Dec 5 (Oregon State, central OR)Transplant outdoors across most of the zone: Jan 18 to Feb 7Transplant outdoors at the zone median: Jan 30 (Colorado State)Plant for fall across most of the zone: Sep 4 to Oct 25Plant for fall at the zone median: Sep 23 to Oct 21 (Texas A&M (E-502))
CucumbersStart indoors across most of the zone: Dec 21 to Jan 10Start indoors at the zone median: Jan 2 (Oregon State, central OR)Transplant outdoors across most of the zone: Jan 11 to Jan 31Transplant outdoors at the zone median: Jan 23 (Oregon State, central OR)Sow outdoors across most of the zone: Jan 4 to Jan 24Sow outdoors at the zone median: Jan 16 (Colorado State)Plant for fall across most of the zone: Oct 2 to Nov 8Plant for fall at the zone median: Oct 21 to Nov 4 (Texas A&M (E-502))
ZucchiniStart indoors across most of the zone: Dec 28 to Jan 17Start indoors at the zone median: Jan 9 (Oregon State, central OR)Transplant outdoors across most of the zone: Jan 18 to Feb 7Transplant outdoors at the zone median: Jan 30 (Oregon State, central OR)Sow outdoors across most of the zone: Jan 4 to Jan 24Sow outdoors at the zone median: Jan 16 (Colorado State)Plant for fall across most of the zone: Sep 11 to Oct 25Plant for fall at the zone median: Sep 30 to Oct 21 (Texas A&M (E-502))
BeansStart indoors across most of the zone: Dec 14 to Jan 3Start indoors at the zone median: Dec 26 (Oregon State, central OR)Transplant outdoors across most of the zone: Jan 11 to Jan 31Transplant outdoors at the zone median: Jan 23 (Oregon State, central OR)Sow outdoors across most of the zone: Jan 4 to Jan 24Sow outdoors at the zone median: Jan 16 (Colorado State)Plant for fall across most of the zone: Oct 16 to Nov 22Plant for fall at the zone median: Nov 4 to Nov 18 (Texas A&M (E-502))Plant for fall across most of the zone: Sep 4 to Oct 11Plant for fall at the zone median: Sep 23 to Oct 7 (Texas A&M (E-502))
PeasStart indoors across most of the zone: Nov 9 to Nov 29Start indoors at the zone median: Nov 21 (Oregon State, central OR)Transplant outdoors across most of the zone: Dec 7 to Dec 27Transplant outdoors at the zone median: Dec 19 (Oregon State, central OR)Sow outdoors across most of the zone: Dec 7 to Jan 10Sow outdoors at the zone median: Dec 19 to Jan 2 (Colorado State)Plant for fall across most of the zone: Oct 2 to Jan 3Plant for fall at the zone median: Oct 21 to Dec 30 (Texas A&M (E-502))
LettuceStart indoors across most of the zone: Nov 16 to Dec 6Start indoors at the zone median: Nov 28 (Oregon State, central OR)Transplant outdoors across most of the zone: Dec 21 to Jan 10Transplant outdoors at the zone median: Jan 2 (Oregon State, central OR)Sow outdoors across most of the zone: Dec 7 to Jan 10Sow outdoors at the zone median: Dec 19 to Jan 2 (Colorado State)Plant for fall across most of the zone: Sep 18 to Nov 8Plant for fall at the zone median: Oct 7 to Nov 4 (Texas A&M (E-502))
CarrotsSow outdoors across most of the zone: Dec 21 to Jan 24Sow outdoors at the zone median: Jan 2 to Jan 16 (Colorado State)Plant for fall across most of the zone: Sep 18 to Oct 25Plant for fall at the zone median: Oct 7 to Oct 21 (Texas A&M (E-502))
OnionsStart indoors across most of the zone: Sep 14 to Oct 4Start indoors at the zone median: Sep 26 (Oregon State, central OR)Transplant outdoors across most of the zone: Nov 23 to Dec 13Transplant outdoors at the zone median: Dec 5 (Oregon State, central OR)Sow outdoors across most of the zone: Dec 7 to Jan 10Sow outdoors at the zone median: Dec 19 to Jan 2 (Colorado State)Plant for fall across most of the zone: Oct 16 to Nov 22Plant for fall at the zone median: Nov 4 to Nov 18 (Texas A&M (E-502))
GarlicPlant for fall across most of the zone: Jan 1 to Jan 31Plant for fall at the zone median: Jan 20 to Jan 27 (Wisconsin)
PotatoesSow outdoors across most of the zone: Dec 21 to Jan 24Sow outdoors at the zone median: Jan 2 to Jan 16 (Colorado State)Plant for fall across most of the zone: Sep 4 to Oct 11Plant for fall at the zone median: Sep 23 to Oct 7 (Texas A&M (E-502))
BasilNo sourced window

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 2. Planting windows across zone 10b. Solid and dashed bars: the window at the zone's median frost dates. Pale bars: where the same window falls across most of the zone's ZIP codes.

Table 1. Planting windows in zone 10b.
Crop	What	Zone median	Across most of the zone	Source
Tomatoes	Start indoors	Nov 21	Nov 9 – Nov 29	Oregon State, central OR3
	Transplant outdoors	Jan 30	Jan 18 – Feb 7	Colorado State4
	Plant for fall	Oct 7 – Oct 21	Sep 18 – Oct 25	Texas A&M (E-502)5
Peppers	Start indoors	Dec 5	Nov 23 – Dec 13	Oregon State, central OR3
	Transplant outdoors	Jan 30	Jan 18 – Feb 7	Colorado State4
	Plant for fall	Sep 23 – Oct 21	Sep 4 – Oct 25	Texas A&M (E-502)5
Cucumbers	Start indoors	Jan 2	Dec 21 – Jan 10	Oregon State, central OR3
	Transplant outdoors	Jan 23	Jan 11 – Jan 31	Oregon State, central OR3
	Sow outdoors	Jan 16	Jan 4 – Jan 24	Colorado State4
	Plant for fall	Oct 21 – Nov 4	Oct 2 – Nov 8	Texas A&M (E-502)5
Zucchini	Start indoors	Jan 9	Dec 28 – Jan 17	Oregon State, central OR3
	Transplant outdoors	Jan 30	Jan 18 – Feb 7	Oregon State, central OR3
	Sow outdoors	Jan 16	Jan 4 – Jan 24	Colorado State4
	Plant for fall	Sep 30 – Oct 21	Sep 11 – Oct 25	Texas A&M (E-502)5
Beans	Start indoors	Dec 26	Dec 14 – Jan 3	Oregon State, central OR3
	Transplant outdoors	Jan 23	Jan 11 – Jan 31	Oregon State, central OR3
	Sow outdoors	Jan 16	Jan 4 – Jan 24	Colorado State4
	Plant for fall	Nov 4 – Nov 18	Oct 16 – Nov 22	Texas A&M (E-502)5
	Plant for fall	Sep 23 – Oct 7	Sep 4 – Oct 11	Texas A&M (E-502)5
Peas	Start indoors	Nov 21	Nov 9 – Nov 29	Oregon State, central OR3
	Transplant outdoors	Dec 19	Dec 7 – Dec 27	Oregon State, central OR3
	Sow outdoors	Dec 19 – Jan 2	Dec 7 – Jan 10	Colorado State4
	Plant for fall	Oct 21 – Dec 30	Oct 2 – Jan 3	Texas A&M (E-502)5
Lettuce	Start indoors	Nov 28	Nov 16 – Dec 6	Oregon State, central OR3
	Transplant outdoors	Jan 2	Dec 21 – Jan 10	Oregon State, central OR3
	Sow outdoors	Dec 19 – Jan 2	Dec 7 – Jan 10	Colorado State4
	Plant for fall	Oct 7 – Nov 4	Sep 18 – Nov 8	Texas A&M (E-502)5
Carrots	Sow outdoors	Jan 2 – Jan 16	Dec 21 – Jan 24	Colorado State4
Carrots	Plant for fall	Oct 7 – Oct 21	Sep 18 – Oct 25	Texas A&M (E-502)5
Onions	Start indoors	Sep 26	Sep 14 – Oct 4	Oregon State, central OR3
	Transplant outdoors	Dec 5	Nov 23 – Dec 13	Oregon State, central OR3
	Sow outdoors	Dec 19 – Jan 2	Dec 7 – Jan 10	Colorado State4
	Plant for fall	Nov 4 – Nov 18	Oct 16 – Nov 22	Texas A&M (E-502)5
Garlic	Plant for fall	Jan 20 – Jan 27	Jan 1 – Jan 31	Wisconsin6
Potatoes	Sow outdoors	Jan 2 – Jan 16	Dec 21 – Jan 24	Colorado State4
Potatoes	Plant for fall	Sep 23 – Oct 7	Sep 4 – Oct 11	Texas A&M (E-502)5
Basil	No frost-relative rule is published; sources give conditions instead (see the crop page).

Sources

PRISM Group, Oregon State University, 2023 USDA Plant Hardiness Zone Map ZIP code data (PHZM 2023), 2023-11-15. Retrieved 2026-11-02.
NOAA National Centers for Environmental Information, U.S. Climate Normals 2020: U.S. Annual/Seasonal Climate Normals (1991-2020), 2021. Retrieved 2026-11-02.
Oregon State University Extension Service, When to start seeds indoors in central Oregon, reviewed 2024. Retrieved 2026-11-02.
Colorado State University Extension, Vegetable Planting Guide (CMG GardenNotes #720), reviewed September 2024. Retrieved 2026-11-02.
Texas AgriLife Extension Service, The Texas A&M System, Texas Home Vegetable Gardening Guide (E-502), 2/09. Retrieved 2026-11-02.
University of Wisconsin–Madison Division of Extension, Wisconsin Horticulture, Garlic, Allium sativum, Rev: 10/2023. Retrieved 2026-11-02.

Zone 10b

When to plant in zone 10b

Sources

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First, I check for frost

Then I make your calendar

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