Washington: Plant Hardiness Zones, Climate & Soil Conditions

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The state of Washington is home to a thriving agricultural industry.

The state’s mild climate and ample rainfall make it ideal for growing a variety of crops, including wheat, corn, potatoes, and apples.

Plant Hardiness Zone

Below is the map showing the US Plant Hardiness Zone in the state of Washington.

Plant Hardiness Zone Map for Washington


The state of Washington has a zone range of 4 to 9a. The state is divided into two distinct climate ranges.

Summers in western Washington are fresh and relatively dry, while they are warmer in the east.

The average temperature goes up to 78˚F in July. On the other hand, winters are mild and wet with mainly cloudy skies and drizzly rain.


Annual rainfall exhibits wide regional variations across the state.

Parts of the Olympic Peninsula receive around 150 inches of precipitation annually, while annual totals average less than 10 inches along the Columbia River in eastern interior Washington.

Soil Type

The ecoregions of the state is shown in the map that follows:-

Now, let us see the soil orders present in the state.

Soil Order Of Washington

Soil / Sub OrderLocationCharacteristics
Andisols/Udands, Vitrands, Cryands, and XerandsFound all over the state except in the Columbia Plateau1. Udands have a udic moisture regime, a temperature regime warmer than cryic, and a relatively high content of water held too tightly for plants to use.
2. Vitrands are the more or less well-drained, coarse-textured Andisols that have a udic or ustic moisture regime, a temperature regime warmer than cryic, and low content of water held too tightly for plants to use.
3. Cryands have a cryic temperature regime.
4.Xerands have a xeric moisture regime and a frigid, mesic, or thermic temperature regime
Aridisols/Majorly CambidsIn the Columbia plateau.1. Cambids are characterized by the least degree of soil development.
Inceptisols/Cryepts and XereptsCryepts in the Cascade Range and Puget lowland while Xerepts in the northern Rockies, Cascade Range, and Puget lowland.1. Cryepts are the cold Inceptisols of high mountains or high latitudes
2. Xerepts are mainly freely drained Inceptisols that have a xeric moisture regime.
Ultisols/HumultsIn the Puget lowlands.1. Humults are the more or less freely drained, humus-rich Ultisols.
Entisols/Aquents and PsammentsAquents in the Puget lowlands and Psamments in the Columbia plateau.1. Aquents are the wet Entisols.
2. Psamments are sandy soils.
Spodosols/Cryods and HumodsCryods in the Cascade ranges and Humods in the coast range.1. Cryods are the cold Spodosols of high latitudes and/or high elevations.
2. Humods are the relatively freely drained Spodosols that have a large accumulation of organic carbon in the spodic horizon.
Alfisols/XeralfsIn the coast range and the northern Rockies.1. Xeralfs have a xeric soil moisture regime.

Best Fruits / Veggies to Grow in the State

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