Tualatin, OR planting zone & frost dates
Tualatin is in USDA hardiness zone 9a. The last spring frost usually comes around April 1 and the first fall frost around November 6, for a growing season of about 222 days.
Planting calendar for Tualatin
Dates are counted from the average last spring frost (April 1) 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 4 – Feb 18 Transplant outdoors: Apr 8 – Apr 15 |
| Peppers | Start seeds indoors: Jan 21 – Feb 4 Transplant outdoors: Apr 15 – Apr 22 |
| Eggplant | Start seeds indoors: Jan 21 – Feb 4 Transplant outdoors: Apr 15 – Apr 22 |
| Broccoli | Start seeds indoors: Jan 21 – Feb 4 Transplant outdoors: Mar 4 – Mar 18 |
| Cabbage | Start seeds indoors: Jan 21 – Feb 4 Transplant outdoors: Mar 4 – Mar 18 |
| Onions (sets) | Plant outdoors: Mar 4 – Mar 18 |
| Peas | Sow outdoors: Feb 18 – Mar 4 |
| Spinach | Sow outdoors: Feb 18 – Mar 4 |
| Lettuce | Sow outdoors: Mar 4 – Mar 18 |
| Carrots | Sow outdoors: Mar 4 – Mar 18 |
| Potatoes | Plant outdoors: Mar 4 – Mar 18 |
| Beans | Sow outdoors: Apr 8 – Apr 15 |
| Sweet corn | Sow outdoors: Apr 8 – Apr 15 |
| Cucumbers | Sow outdoors: Apr 8 – Apr 15 |
| Squash & zucchini | Sow outdoors: Apr 8 – Apr 15 |
| Basil | Start seeds indoors: Feb 18 – Mar 4 Transplant outdoors: Apr 8 – Apr 15 |
Fall garden: cool-season crops like lettuce, spinach and kale can be sown again around Sep 11 (8 weeks before the average first fall frost on Nov 6).
Useful for zone 9a 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
- Shade cloth — for hot summers
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Frost risk in detail
| 90% chance | 50% chance | 10% chance | |
|---|---|---|---|
| Last 32°F frost in spring is after | Mar 5 | Apr 1 | Apr 26 |
| First 32°F frost in fall is before | Dec 1 | Nov 6 | Oct 19 |
How to read it: in spring there is a 10% chance of a frost after April 26, so that is a safe date for tender plants. In fall there is a 10% chance of frost before October 19. A hard freeze (28°F) usually ends around February 26.
Hardiness zone by ZIP code in Tualatin
- 97062 zone 9a
Nearby cities
- Tigard zone 9a, last frost Apr 1
- Sherwood zone 8b, last frost Mar 21
- Wilsonville zone 8b, last frost Mar 18
- Lake Oswego zone 9a, last frost Mar 18
- Beaverton zone 9a, last frost Feb 11
- Oak Grove zone 9a, last frost Mar 18
- Milwaukie zone 9a, last frost Feb 25
- Canby zone 8b, last frost Mar 18
Questions
What growing zone is Tualatin, OR?
Tualatin is in USDA Plant Hardiness Zone 9a (average extreme winter low 20°F to 25°F), according to the USDA 2023 map.
When is the last frost in Tualatin?
The average last spring frost (32°F) in Tualatin is April 1. There is still a 10% chance of frost until April 26.
When can I plant tomatoes in Tualatin?
Transplant tomatoes outdoors 1–2 weeks after the average last frost: around Apr 8 – Apr 15. Start seeds indoors 6–8 weeks before the last frost.
Frost dates: NOAA U.S. Climate Normals 1991–2020, station Beaverton 2 Ssw, OR (USC00350595), 9.0 km (5.6 mi) from the city center, elevation 82 m, based on 15 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.