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Clackamas County Soil Data

Clackamas County, Oregon

USDA SSURGO / PHZM

Avg pH

N/A

Texture

Unknown

Drainage

N/A

Organic Matter

N/A

Hydrologic Group

N/A

Data Story

About Soil in Clackamas County, Oregon

Mountain-Fed Valley Soils

Clackamas County lacks specific taxonomic and pH data in current regional soil datasets. However, it generally follows the Oregon trend of acidic profiles that fall well below the national median pH of 6.5.

Undocumented Textures and Mixes

Specific percentages for sand, silt, and clay are not available for this county. Given its location, the soil likely ranges from mountain loams to silty valley deposits that offer varied drainage for local farms.

Potential for High Organic Richness

While specific organic matter data is missing, the county sits in a region known for fertile volcanic soils that often match or exceed the state's 29.41% organic average. Gardeners typically find deep, productive ground in the lower valley reaches.

Diverse Hydrology from Peaks to Plains

Formal drainage and hydrologic group data are not recorded at the county-wide level. Site-specific observations are necessary, as drainage can shift rapidly from well-draining slopes to heavy, saturated lowland clays.

A Versatile Zone 8b Haven

Clackamas County occupies USDA Hardiness Zone 8b, supporting an incredible range of nursery crops, Christmas trees, and berry varieties. Take advantage of the long growing season by starting your seeds early in this temperate climate.

Soil Composition

Composition data not available for this county.

Soil pH

pH data not available for this county.

Soil Series

Detailed soil series data not yet available for this county.

Hydrologic Group

Hydrologic group data not available.

Drainage Class

Drainage class data not available.

Soil Profile

Dominant texture: Unknown

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.

Soil Amendment Products

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Frequently Asked Questions

What type of soil does Clackamas County have?

Clackamas County's soil is classified as Unknown. This indicates the relative proportions of sand, silt, and clay — sand percentage unavailable, silt percentage unavailable, and clay percentage unavailable. Sandy soils drain quickly but may need more frequent irrigation and fertilization.

Is Clackamas County's soil acidic or alkaline?

pH data is not available for Clackamas County.

What is the drainage class for Clackamas County?

Drainage class data is not currently available for Clackamas County.

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

Based on Clackamas County's Unknown texture, soil pH, and drainage class, the soil is well suited for a variety of crops depending on local conditions.

What USDA soil order is found in Clackamas County?

The dominant USDA soil order for Clackamas County is not currently available in our dataset.

Soil & Planting Advisory: Clackamas County

Soil Verdict

Clackamas County is in USDA hardiness zone 8b, a warm climate zone. where winter lows can reach 15°F. Mild winters mean soil rarely freezes deeply, allowing year-round microbial activity and faster organic matter breakdown.

Planting Guidance

Warm-season crops, citrus relatives, and heat-loving ornamentals do well. Cool-season vegetables should be planted in fall and winter. Always match plant selections to the specific microclimate of your property — low spots, slopes, and wind exposure can shift effective hardiness by half a zone.

Soil Implications

Warm soils accelerate organic matter breakdown, so compost and mulch need replenishing more frequently than in cooler zones. Sandy soils common in warm zones drain quickly; water-retentive amendments like compost or peat help hold moisture.

Regional Context

Clackamas County is somewhat warmer than the Oregon statewide average. The zone range of 7b-9a within the county means soil and planting decisions should account for local elevation and topography.

Other Counties in Oregon

By Evan Brooks, Data EditorUpdated Reviewed by Evan Brooks, Data Editor

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.