Washington County Soil Data
Washington County, Indiana
USDA SSURGO / PHZMAvg pH
5.9
Texture
Silty clay loam
Drainage
Poorly drained
Organic Matter
2.2%
Hydrologic Group
C/D
Data Story
About Soil in Washington County, Indiana
Washington County’s Acidic Clay-Silt Mix
The county’s Inceptisols feature a silty clay loam texture and a relatively acidic pH of 5.86. This level is notably lower than both the national median of 6.5 and the Indiana average of 6.08.
Dense Silty Clay Loam Structure
The soil composition is 67.1% silt and 17.1% clay, which can lead to a heavy, slow-draining feel. The 15.8% sand content is insufficient to provide rapid drainage, so the soil often stays cool and damp in the spring.
Good Moisture Retention Despite Acidity
Organic matter sits at 2.22%, which is healthy by national standards but below the state’s high average. The available water capacity of 0.207 in/in is better than the state average, providing a good buffer against summer drought.
Poor Drainage Limits Wet-Season Use
Washington County soils are poorly drained and fall into hydrologic group C/D. This means the soil is frequently saturated, making it a challenge for building foundations and requiring careful water management in fields.
Acid-Loving Plants Excel in Zone 6b
The slightly acidic soil is perfect for blueberries and azaleas in this 6b hardiness zone. For traditional vegetables, adding lime can help balance the pH to unlock more nutrients for your garden.
Soil Composition
Soil pH
Soil Series
Detailed soil series data not yet available for this county.
Hydrologic Group
Group C — Moderate-High Runoff
Soils with slow infiltration rates, often with a layer that impedes downward water movement. Higher clay content restricts drainage.
Drainage Class
Poorly drained
Water is removed so slowly that the soil is wet at or near the surface much of the year. Drainage improvement usually needed.
Soil Profile
Dominant texture: Silty clay loam
Typical soil profile. Actual depths vary by location.
USDA Soil Orders
Acidic Soil Detected
Your county's average pH is 5.9. These products help balance soil pH for healthier grass.
Browse Soil AmendmentsFrequently Asked Questions
What type of soil does Washington County have?
Washington County's soil is classified as Silty clay loam. This indicates the relative proportions of sand, silt, and clay — 16% sand, 67% silt, and 17% 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 5.9, 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?
Washington County has a dominant drainage class of "Poorly drained." Poorly drained soils retain water for extended periods, which can limit crop choices and may require tile drainage or raised beds.
What crops or plants grow well in Washington County's soil?
Based on Washington County's Silty clay loam texture, pH of 5.9, and Poorly drained, the soil is well suited for vegetables, grains, and most field crops, row crops and vegetable gardens, rice, cranberries, and other water-tolerant species.
What USDA soil order is found in Washington County?
Washington County's dominant soil order is Inceptisols. Inceptisols are young soils with weak horizon development. They occur in a wide range of climates and parent materials.
Soil & Planting Advisory: Washington County
Soil Verdict
Washington County is in USDA hardiness zone 6b, a moderate climate zone. where winter lows can reach -5°F. Freeze-thaw cycles are moderate; soil biology slows in winter but recovers reliably in spring, supporting a broad range of plants.
Planting Guidance
A wide plant palette is possible: deciduous trees, most shrubs, cool-season vegetables, and many perennials thrive here. Winter protection (mulch, burlap wraps) helps push the zone boundary for desired species. 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
Moderate freeze-thaw cycles naturally aerate the soil but can also cause compaction in clay-heavy areas; annual core aeration is beneficial. Organic matter amendments decompose at a moderate pace — aim for 3-5% organic content for optimal fertility. When soil temperatures drop below freezing, microbial nitrogen cycling stops; spring fertilization is more effective than late-fall application.
Regional Context
Washington County closely matches the Indiana average hardiness conditions.
Planning your lawn? View lawn care data for Washington County on LawnByCounty.com →
Other Counties in Indiana
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.