USDA zone 9b in Washington
USDA plant hardiness zone 9b covers 1 location across Washington (average annual extreme minimum 25 to 30 °F): Tokeland, WA. Average last spring frost across this group ranges March 29 and growing seasons run 224 days — even within one state, because hardiness sets winter survival, not planting dates. The table below gives every Washington location's own frost dates; the printable planting calendar uses Tokeland, this group's median-season location.
- USDA zone
- 9b25 to 30 °F
- Last frost range
- Mar 29avg, 32°F
- First frost range
- Nov 7avg, 32°F
- Growing season range
- 224days
Locations in this group
Every location below shares this zone and a nearby weather station, but keeps its own frost dates — find your town for its own numbers, or use the ZIP planner on the home page for an instant personalized answer.
| Location | Also covers | Nearest station | Last frost | First frost | Season (days) |
|---|---|---|---|---|---|
| Tokeland * | — | Grayland | Mar 29 | Nov 7 | 224 |
* Tokeland is this group's median-season location — the calendar below is computed from its data.
Data: NOAA NCEI U.S. Climate Normals 1991–2020 (public domain) and USDA Plant Hardiness Zone Map 2023. Planting windows synthesized from U.S. Cooperative Extension guides.
Planting calendar (Tokeland, representative)
Computed from Tokeland's average frost dates — the median-season location in this Washingtonzone 9b group. hatched = start seeds indoors, solid green = plant out, teal = a fall sowing, and the terracotta dot marks the estimated first harvest. Ranges are extension-guide planning guidance, not guarantees — your own location's dates may run a week or two earlier or later (see the table above).
- Start indoors
- Plant out
- Fall sowing
- First harvest
| Crop | Frost tolerance | Start indoors | Plant out | First harvest | Fall planting | Season fit |
|---|---|---|---|---|---|---|
| Tomato | Tender | Feb 1 – Feb 15 | Apr 5 – Apr 12 | Jun 4 – Jun 24 | — | matures comfortably |
| Pepper | Very tender | Jan 18 – Feb 1 | Apr 12 – Apr 19 | Jun 11 – Jul 11 | — | matures comfortably |
| Cucumber | Tender | Mar 1 – Mar 8 | Apr 5 – Apr 12 | May 25 – Jun 14 | — | matures comfortably |
| Summer squash / zucchini | Tender | — | Apr 5 – Apr 12 | May 20 – Jun 4 | — | matures comfortably |
| Bush bean | Tender | — | Apr 5 – Apr 12 | May 25 – Jun 4 | Sep 8 – Sep 18 | matures comfortably |
| Sweet corn | Tender | — | Mar 29 – Apr 12 | May 28 – Jun 27 | — | matures comfortably |
| Basil | Very tender | Feb 15 – Mar 1 | Apr 5 – Apr 12 | May 5 – May 20 | — | matures comfortably |
| Lettuce | Half-hardy | Feb 15 – Mar 1 | Mar 1 – Mar 15 | Apr 15 – Apr 30 | Aug 25 – Sep 9 | matures comfortably |
| Pea | Hardy | — | Feb 15 – Mar 1 | Apr 11 – Apr 26 | Aug 15 – Aug 30 | matures comfortably |
| Spinach | Hardy | — | Feb 15 – Mar 1 | Mar 27 – Apr 6 | Sep 4 – Sep 14 | matures comfortably |
| Carrot | Half-hardy | — | Mar 8 – Mar 15 | May 7 – May 27 | Aug 5 – Aug 25 | matures comfortably |
| Broccoli | Half-hardy | Feb 1 – Feb 15 | Mar 1 – Mar 15 | Apr 25 – May 15 | Aug 10 – Aug 30 | matures comfortably |
Which crops fit this growing season
Using Tokeland's own 224-day growing season (32°F, NOAA 1991–2020 median) against each crop's real days-to-maturity range: 12 of 12 crops mature here with comfortable margin. A different location in the table above with a longer or shorter season will get a different mix — the ZIP planner on the home page gives your own.
Frost & freeze dates (Tokeland)
From NOAA's 1991–2020 Climate Normals at station USC00453320. The median (p50) is the average date; the 90%-safe column is the date the freeze has passed in about 9 years out of 10 — the conservative date to plant after or harvest before.
| Threshold | Last spring — avg | Last spring — 90%-safe | First fall — avg | First fall — 90%-safe | Season (days) |
|---|---|---|---|---|---|
| 36°F | Apr 29 | May 27 | Oct 16 | Nov 5 | 171 |
| 32°F (freeze) | Mar 29 | Apr 24 | Nov 7 | Dec 1 | 224 |
| 28°F | Feb 22 | Mar 24 | Dec 1 | Jan 8 | 284 |
| 24°F | Jan 21 | Feb 23 | Dec 20 | Feb 9 | 342 |
Growing degree days
Growing degree days (GDD) accumulate warmth above a base temperature over the year — a better predictor of crop development than the calendar alone. This group's median GDD (base 50°F) across all 1 locations is 1,304; Tokeland's own reading is shown below.
| Model | °F·days | Used for |
|---|---|---|
| Base 50°F (warm-season) | 1,304 | standard warm-season base (tomato, corn, beans) |
| Base 40°F (cool-season) | 4,038 | cool-season crops (brassicas, greens) |
Hardiness zone 9b in Washington
Zone 9b means an average annual extreme minimum winter temperature of about 25 to 30 °F on the USDA's 2023 map — the number that tells you which perennials, shrubs, and trees reliably survive an average winter here. It does not set your planting dates, which come from the frost calendar above. Washington spans 8 hardiness zones in this dataset — see all Washington locations for the full range, including zones6a, 6b, 7a, 7b, 8a, 8b, 9a.
Explore zone 9b in other states at zone 9b, or see all USDA hardiness zones.
Frequently asked questions
- What does USDA hardiness zone 9b mean in Washington?
- Zone 9b means an average annual extreme minimum winter temperature of 25 to 30 °F — the standard USDA measure of which perennials survive winter. 1 location in Washington fall in this zone. It does not set planting dates; see the frost calendar below for that.
- When should I plant tomatoes in Washington's zone 9b?
- Using Tokeland's frost dates (this page's median-season location): start seeds indoors about Feb 1 – Feb 15, then transplant outside about Apr 5 – Apr 12. Your own location in the table above may differ by a week or two — use the ZIP planner on the home page for your exact station's dates.
- Does every location in Washington's zone 9b have the same frost dates?
- No — they do not all share a weather station, so frost dates vary by a week or more across the 1 locations listed (see the table above for each location's own dates).
Sources & method
Frost, freeze, growing-season, and growing-degree-day figures are NOAA NCEI U.S. Climate Normals 1991–2020, one reading per location's own nearest station (see the table above). The hardiness zone is the USDA Plant Hardiness Zone Map 2023, matched to each location's ZIP. Planting windows are computed by counting from the average last and first frost using per-crop offsets synthesized from U.S. Cooperative Extension guides — the full method and citations are on the methodology page.