Pacific Northwest USDA Zones. Even in each state, growing zones are varied. Washington is designated as UDSA zones 4a–9a – while Seattle may be 9a, Spokane is 6b.

In the Pacific Northwest, USDA hardiness zones span 6 to 9, but there are some areas where it is zone 4. This means it is difficult to pinpoint exact timings for the whole region in spring.

The USDA divides the United States into seven planting regions, known as hardiness zones, which were most recently updated in 2023. The maps below show these planting regions.

Now's the time to be planting and replanting your Pacific Northwest garden. Ann Lovejoy. ... The planting and transplanting sweet spot is the period between mid-October and mid-December, ...

If your tomatoes get full sun (10-14 hours a day), that’s ideal. If not, they may do better in large pots than in the ground. Give each plant a pot that holds 2-3 cubic feet of potting soil.

Plant young tomatoes sideways, in trenches, placing 3-6 inches of main stem under the soil. This would kill some other plants, but tomatoes grow fresh roots from that buried “neck.” ...