Bremerton, WA planting zone & frost dates
Bremerton is in USDA hardiness zone 9a. The last spring frost usually comes around March 29 and the first fall frost around November 14, for a growing season of about 227 days.
Planting calendar for Bremerton
Dates are counted from the average last spring frost (March 29) 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 1 – Feb 15 Transplant outdoors: Apr 5 – Apr 12 |
| Peppers | Start seeds indoors: Jan 18 – Feb 1 Transplant outdoors: Apr 12 – Apr 19 |
| Eggplant | Start seeds indoors: Jan 18 – Feb 1 Transplant outdoors: Apr 12 – Apr 19 |
| Broccoli | Start seeds indoors: Jan 18 – Feb 1 Transplant outdoors: Mar 1 – Mar 15 |
| Cabbage | Start seeds indoors: Jan 18 – Feb 1 Transplant outdoors: Mar 1 – Mar 15 |
| Onions (sets) | Plant outdoors: Mar 1 – Mar 15 |
| Peas | Sow outdoors: Feb 15 – Mar 1 |
| Spinach | Sow outdoors: Feb 15 – Mar 1 |
| Lettuce | Sow outdoors: Mar 1 – Mar 15 |
| Carrots | Sow outdoors: Mar 1 – Mar 15 |
| Potatoes | Plant outdoors: Mar 1 – Mar 15 |
| Beans | Sow outdoors: Apr 5 – Apr 12 |
| Sweet corn | Sow outdoors: Apr 5 – Apr 12 |
| Cucumbers | Sow outdoors: Apr 5 – Apr 12 |
| Squash & zucchini | Sow outdoors: Apr 5 – Apr 12 |
| Basil | Start seeds indoors: Feb 15 – Mar 1 Transplant outdoors: Apr 5 – Apr 12 |
Fall garden: cool-season crops like lettuce, spinach and kale can be sown again around Sep 19 (8 weeks before the average first fall frost on Nov 14).
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 | Mar 29 | Apr 24 |
| First 32°F frost in fall is before | Dec 1 | Nov 14 | Oct 26 |
How to read it: in spring there is a 10% chance of a frost after April 24, so that is a safe date for tender plants. In fall there is a 10% chance of frost before October 26. A hard freeze (28°F) usually ends around February 27.
Hardiness zone by ZIP code in Bremerton
- 98310 zone 8b
- 98311 zone 9a
- 98312 zone 8b
- 98337 zone 9a
Nearby cities
- Port Orchard zone 9a, last frost Mar 29
- Silverdale zone 8b, last frost Mar 29
- Bainbridge Island zone 9a, last frost Mar 29
- Poulsbo zone 8b, last frost Mar 29
- Vashon zone 9a, last frost Mar 2
- Artondale zone 9a, last frost Mar 11
- White Center zone 9a, last frost Mar 13
- Burien zone 9a, last frost Mar 2
Questions
What growing zone is Bremerton, WA?
Bremerton is in USDA Plant Hardiness Zone 9a (average extreme winter low 20°F to 25°F), according to the USDA 2023 map. Some ZIP codes of the city fall in zone 8b.
When is the last frost in Bremerton?
The average last spring frost (32°F) in Bremerton is March 29. There is still a 10% chance of frost until April 24.
When can I plant tomatoes in Bremerton?
Transplant tomatoes outdoors 1–2 weeks after the average last frost: around Apr 5 – Apr 12. Start seeds indoors 6–8 weeks before the last frost.
Frost dates: NOAA U.S. Climate Normals 1991–2020, station Bremerton, WA (USC00450872), 3.8 km (2.4 mi) from the city center, elevation 34 m, based on 26 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.