Kelso, WA planting zone & frost dates
Kelso is in USDA hardiness zone 8b. The last spring frost usually comes around April 8 and the first fall frost around November 5, for a growing season of about 210 days.
Planting calendar for Kelso
Dates are counted from the average last spring frost (April 8) using the typical timing recommended by U.S. extension services. Warm-season crops go out only after the danger of frost has passed and the soil has warmed.
| Crop | When |
|---|---|
| Tomatoes | Start seeds indoors: Feb 11 – Feb 25 Transplant outdoors: Apr 15 – Apr 22 |
| Peppers | Start seeds indoors: Jan 28 – Feb 11 Transplant outdoors: Apr 22 – Apr 29 |
| Eggplant | Start seeds indoors: Jan 28 – Feb 11 Transplant outdoors: Apr 22 – Apr 29 |
| Broccoli | Start seeds indoors: Jan 28 – Feb 11 Transplant outdoors: Mar 11 – Mar 25 |
| Cabbage | Start seeds indoors: Jan 28 – Feb 11 Transplant outdoors: Mar 11 – Mar 25 |
| Onions (sets) | Plant outdoors: Mar 11 – Mar 25 |
| Peas | Sow outdoors: Feb 25 – Mar 11 |
| Spinach | Sow outdoors: Feb 25 – Mar 11 |
| Lettuce | Sow outdoors: Mar 11 – Mar 25 |
| Carrots | Sow outdoors: Mar 11 – Mar 25 |
| Potatoes | Plant outdoors: Mar 11 – Mar 25 |
| Beans | Sow outdoors: Apr 15 – Apr 22 |
| Sweet corn | Sow outdoors: Apr 15 – Apr 22 |
| Cucumbers | Sow outdoors: Apr 15 – Apr 22 |
| Squash & zucchini | Sow outdoors: Apr 15 – Apr 22 |
| Basil | Start seeds indoors: Feb 25 – Mar 11 Transplant outdoors: Apr 15 – Apr 22 |
Fall garden: cool-season crops like lettuce, spinach and kale can be sown again around Sep 10 (8 weeks before the average first fall frost on Nov 5).
Useful for zone 8b gardens
- Seed starting kit with dome — to start seeds indoors before the last frost
- LED grow light for seedlings — stops leggy seedlings
- Frost cloth / plant covers — for late spring and early fall frosts
- Soil thermometer — warm-season crops need soil above 60°F
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Frost risk in detail
| 90% chance | 50% chance | 10% chance | |
|---|---|---|---|
| Last 32°F frost in spring is after | Mar 11 | Apr 8 | May 2 |
| First 32°F frost in fall is before | Nov 28 | Nov 5 | Oct 17 |
How to read it: in spring there is a 10% chance of a frost after May 2, so that is a safe date for tender plants. In fall there is a 10% chance of frost before October 17. A hard freeze (28°F) usually ends around March 6.
Hardiness zone by ZIP code in Kelso
- 98626 zone 8b
Nearby cities
- Longview zone 8b, last frost Apr 8
- Salmon Creek zone 8b, last frost Apr 26
- Battle Ground zone 8b, last frost Apr 26
- Hazel Dell zone 8b, last frost Apr 26
- Vancouver zone 8b, last frost Mar 29
- Five Corners zone 8b, last frost Apr 26
- Centralia zone 8b, last frost Apr 22
- Orchards zone 8b, last frost Apr 26
Questions
What growing zone is Kelso, WA?
Kelso is in USDA Plant Hardiness Zone 8b (average extreme winter low 15°F to 20°F), according to the USDA 2023 map.
When is the last frost in Kelso?
The average last spring frost (32°F) in Kelso is April 8. There is still a 10% chance of frost until May 2.
When can I plant tomatoes in Kelso?
Transplant tomatoes outdoors 1–2 weeks after the average last frost: around Apr 15 – Apr 22. Start seeds indoors 6–8 weeks before the last frost.
Frost dates: NOAA U.S. Climate Normals 1991–2020, station Longview, WA (USC00454769), 0.7 km (0.4 mi) from the city center, elevation 4 m, based on 25 years of records. Hardiness zone: USDA Plant Hardiness Zone Map 2023 for the ZIP code nearest to the city center. Microclimates (valleys, hills, cities, coasts) can be warmer or colder: check the local forecast before planting. How we calculate the data.