Washington County Soil Data
Washington County, Iowa
Avg pH
6.3
Texture
Silt Loam
Drainage
N/A
Organic Matter
2.5%
Hydrologic Group
N/A
Data Story
About Soil in Washington County, Iowa
Washington County's Productive Soil Identity
The average soil pH here is 6.28, just under the national median of 6.5. While detailed taxonomic orders are not currently specified, the pH level is ideal for most Midwestern agricultural applications. This slightly acidic profile supports a wide range of native flora and cultivated crops.
Silt-Dominant Soil Structure
Washington County soils are composed of 56.4% silt, 24.5% clay, and 19.0% sand. This high silt concentration provides a silky texture that is excellent for seedbeds and root development. The clay content provides the necessary 'grip' for nutrient retention, though it can make the soil sticky when saturated.
Solid Moisture and Moderate Organic Content
The organic matter level in Washington County is 2.51%, while the available water capacity is 0.188 in/in. Both figures sit below the Iowa state averages of 3.81% and 0.195 in/in, respectively. Gardeners may want to add compost to boost organic levels and improve the soil's ability to hold onto summer rain.
Hydraulic Dynamics and Soil Workability
With a high percentage of fine particles, the soil here can be slow to drain during the spring thaw. While specific drainage classes aren't listed, the silt-heavy profile typically requires careful timing to avoid tilling wet earth. Managing surface water is a priority for maintaining soil health and preventing erosion.
Zone 5b Gardening Potential
Hardiness Zone 5b allows for a long growing season that supports peppers, tomatoes, and beans. Adding organic amendments will help balance the lower water capacity found in this county's soil. It is a great environment for establishing a productive home orchard or a diverse vegetable patch.
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: Silt Loam
Typical soil profile. Actual depths vary by location.
USDA Soil Orders
Frequently Asked Questions
What type of soil does Washington County have?
Washington County's soil is classified as Silt Loam. This indicates the relative proportions of sand, silt, and clay — 19% sand, 56% silt, and 25% clay. Loamy soils hold moisture well and support a wide range of plants.
Is Washington County's soil acidic or alkaline?
Washington County's soil has a pH of 6.3, which is moderately acidic. This range suits many crops and is common across much of the eastern US.
What is the drainage class for Washington County?
Drainage class data is not currently available for Washington County.
What crops or plants grow well in Washington County's soil?
Based on Washington County's Silt Loam texture, pH of 6.3, and drainage class, the soil is well suited for vegetables, grains, and most field crops, row crops and vegetable gardens.
What USDA soil order is found in Washington County?
The dominant USDA soil order for Washington County is not currently available in our dataset.
Planning your lawn? View lawn care data for Washington County on LawnByCounty.com →
Other Counties in Iowa
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.