Cowlitz County Soil Data

Cowlitz County, Washington

Avg pH

5.6

Texture

Loam

Drainage

Well drained

Organic Matter

5.5%

Hydrologic Group

B

Data Story

About Soil in Cowlitz County, Washington

Forest-Rich Alfisols and Loam

Cowlitz County features Alfisols with a loam texture and an acidic pH of 5.59. This is notably more acidic than the national median of 6.5, reflecting the heavy rainfall and evergreen cover of western Washington.

The Perfect Loam Balance

The soil consists of 42.2% sand, 40.9% silt, and 13.2% clay. This balanced loam texture offers easy drainage, good aeration, and enough clay to hold onto fertilizers for your plants.

Strong Organic Foundation

With 5.51% organic matter, these soils are quite rich compared to the 2.0% national average. The available water capacity is 0.157 in/in, which is slightly lower than the state average but still supports vigorous forest growth.

Ideal Drainage for Modern Use

The soil drains well and falls into hydrologic group B, making it ideal for most land uses. It sheds excess water quickly to prevent root rot while remaining stable enough for building foundations.

Berries and Blooms in Zone 8b

Zone 8b provides a gentle climate where strawberries and salad greens thrive. The naturally acidic soil is a perfect match for acid-loving shrubs like azaleas and camellias, so get out there and start digging.

Soil Composition

Loam
Sand: 42.2%
Silt: 40.9%
Clay: 13.2%
Loam

Soil pH

5.6pH
5.58876023023904
Strongly AcidicSlightly AcidicNeutralSlightly AlkalineStrongly Alkaline
Ideal lawn range: 6.0 - 7.0

Soil Series

Detailed soil series data not yet available for this county.

Hydrologic Group

Group B — Moderate Runoff

Moderately deep, moderately well-drained soils with moderate infiltration rates. Good balance of drainage and water retention.

Runoff potential:Moderate

Drainage Class

Well drained

Water is removed from the soil readily but not rapidly. Optimal for most plants and construction.

Soil Profile

Dominant texture: Loam

O HorizonOrganic layer
0-2"
A HorizonTopsoil
2-10"
B HorizonSubsoil
10-30"
C HorizonParent material
30-60"
R HorizonBedrock
60"+

Typical soil profile. Actual depths vary by location.

Frequently Asked Questions

What type of soil does Cowlitz County have?

Cowlitz County's soil is classified as Loam. This indicates the relative proportions of sand, silt, and clay — 42% sand, 41% silt, and 13% clay. Loamy soils hold moisture well and support a wide range of plants.

Is Cowlitz County's soil acidic or alkaline?

Cowlitz County's soil has a pH of 5.6, which is moderately acidic. This range suits many crops and is common across much of the eastern US.

What is the drainage class for Cowlitz County?

Cowlitz County has a dominant drainage class of "Well drained." Well-drained soils allow excess water to move through quickly, reducing waterlogging risk and supporting most field and garden crops.

What crops or plants grow well in Cowlitz County's soil?

Based on Cowlitz County's Loam texture, pH of 5.6, and Well drained, the soil is well suited for vegetables, grains, and most field crops, row crops and vegetable gardens, most annual and perennial crops.

What USDA soil order is found in Cowlitz County?

Cowlitz County's dominant soil order is Alfisols. Alfisols are moderate to high base-status soils with a clay-enriched subsoil. They support productive forests and cropland across temperate regions.

Other Counties in Washington

Soil data sourced from USDA SSURGO via Soil Data Access. Data is informational only and should not be used as a substitute for on-site soil testing. Contact your local NRCS office for site-specific soil information.