Clatsop County Soil Data
Clatsop County, Oregon
USDA SSURGO / PHZMAvg pH
4.5
Texture
Loam
Drainage
N/A
Organic Matter
50.1%
Hydrologic Group
N/A
Data Story
About Soil in Clatsop County, Oregon
Highly Acidic Coastal Ground
Clatsop County soil is notably acidic, with an average pH of 4.52. This is significantly lower than both the state average of 5.26 and the national median of 6.5, reflecting heavy rainfall and coastal leaching.
Silts and Sands of the Coast
The soil mix consists of 48.4% silt and 32.8% sand, with a relatively low 15.6% clay content. This composition facilitates good drainage and prevents the soil from becoming overly heavy during the rainy winters.
Elite Organic Matter Levels
The county features an extraordinary organic matter content of 50.09%, nearly double the Oregon state average. Combined with an available water capacity of 0.351 in/in, these soils have immense potential for nutrient-heavy growth.
Wet-Weather Hydrology Management
Though specific drainage classes are missing, the high silt and sand content usually prevents extreme waterlogging. However, the high water capacity means these soils remain damp and productive deep into the dry season.
Gardening in Maritime Zone 9a
The mild 9a hardiness zone and acidic soil are ideal for acid-loving crops like blueberries, huckleberries, and rhododendrons. You can grow year-round here, provided you choose plants that can tolerate the high moisture levels.
Soil Composition
Soil pH
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: Loam
Typical soil profile. Actual depths vary by location.
USDA Soil Orders
Acidic Soil Detected
Your county's average pH is 4.5. These products help balance soil pH for healthier grass.
Browse Soil AmendmentsFrequently Asked Questions
What type of soil does Clatsop County have?
Clatsop County's soil is classified as Loam. This indicates the relative proportions of sand, silt, and clay — 33% sand, 48% silt, and 16% clay. Loamy soils hold moisture well and support a wide range of plants.
Is Clatsop County's soil acidic or alkaline?
Clatsop County's soil has a low pH of 4.5, which is strongly acidic. Acidic soils benefit from lime applications to raise pH and improve nutrient availability.
What is the drainage class for Clatsop County?
Drainage class data is not currently available for Clatsop County.
What crops or plants grow well in Clatsop County's soil?
Based on Clatsop County's Loam texture, pH of 4.5, and drainage class, the soil is well suited for acid-loving plants like blueberries and azaleas, row crops and vegetable gardens.
What USDA soil order is found in Clatsop County?
The dominant USDA soil order for Clatsop County is not currently available in our dataset.
Soil & Planting Advisory: Clatsop County
Soil Verdict
Clatsop County is in USDA hardiness zone 9a, a warm climate zone. where winter lows can reach 20°F. Warm winters keep soil biology active nearly year-round, accelerating decomposition but increasing pest and disease pressure in topsoil.
Planting Guidance
Tropical and subtropical plants are viable. Year-round gardening is possible, though summer heat may limit some cool-season crops. Frost is rare; tender plants can overwinter with minimal protection. 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
Rapid organic matter turnover means soils can become nutrient-poor quickly; test annually and fertilize based on results. High soil temperatures favor certain soilborne pathogens; practice crop rotation and avoid overwatering.
Regional Context
Clatsop County is significantly warmer than the Oregon average, shifting effective hardiness by roughly 1.6 zones. The zone range of 8b-9a within the county means soil and planting decisions should account for local elevation and topography.
Planning your lawn? View lawn care data for Clatsop County on LawnByCounty.com →
Other Counties in Oregon
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.