Coos County Soil Data
Coos County, Oregon
USDA SSURGO / PHZMAvg pH
4.7
Texture
Loam
Drainage
N/A
Organic Matter
38.0%
Hydrologic Group
N/A
Data Story
About Soil in Coos County, Oregon
Deeply Acidic Coastal Loams
Coos County features highly acidic soil with an average pH of 4.71. This is well below the state average of 5.26 and significantly more acidic than the national median of 6.5, which defines the local flora's character.
Balanced Sandy-Silt Composition
The soil is comprised of 47.7% silt and 32.0% sand, with clay making up 17.4%. This balance prevents the soil from becoming too dense and allows for decent drainage through the sandy particles during high-rainfall events.
Vibrant Organic Foundations
Organic matter content is high at 38.00%, surpassing the state average of 29.41%. The available water capacity of 0.307 in/in is also above average, indicating that the soil is exceptionally good at storing water for plant use.
Coastal Water Management
Specific drainage classes are not currently recorded in the county dataset. However, the high organic matter and sand content usually work together to manage the heavy coastal moisture without losing all nutrient content to leaching.
Marine Climate Success in 9a
The 9a hardiness zone is perfect for specialty crops like cranberries and blueberries that love acidic environments. If you are starting a garden, lean into the local climate by planting berries and maritime-adapted shrubs.
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 4.7. These products help balance soil pH for healthier grass.
Browse Soil AmendmentsFrequently Asked Questions
What type of soil does Coos County have?
Coos County's soil is classified as Loam. This indicates the relative proportions of sand, silt, and clay — 32% sand, 48% silt, and 17% clay. Loamy soils hold moisture well and support a wide range of plants.
Is Coos County's soil acidic or alkaline?
Coos County's soil has a low pH of 4.7, which is strongly acidic. Acidic soils benefit from lime applications to raise pH and improve nutrient availability.
What is the drainage class for Coos County?
Drainage class data is not currently available for Coos County.
What crops or plants grow well in Coos County's soil?
Based on Coos County's Loam texture, pH of 4.7, 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 Coos County?
The dominant USDA soil order for Coos County is not currently available in our dataset.
Soil & Planting Advisory: Coos County
Soil Verdict
Coos 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
Coos County is significantly warmer than the Oregon average, shifting effective hardiness by roughly 1.6 zones. The zone range of 9a-9b within the county means soil and planting decisions should account for local elevation and topography.
Planning your lawn? View lawn care data for Coos 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.