Putnam County Soil Data
Putnam County, Illinois
Avg pH
6.5
Texture
Silt Loam
Drainage
N/A
Organic Matter
2.5%
Hydrologic Group
N/A
Data Story
About Soil in Putnam County, Illinois
Neutral Soils in Putnam County
Putnam County maintains a stable average pH of 6.48, which is nearly identical to the national median of 6.5. This near-neutrality makes the soil highly versatile for a diverse range of crops and ornamental plants.
A Coarser, Sandier Mix
With 27.6% sand and 52.1% silt, this soil is coarser than many other Illinois counties. The higher sand content aids in natural drainage and makes the soil easier to work in the early spring thaw.
Healthy Organic Matter Levels
Organic matter sits at 2.46%, which is higher than the national 2.0% average but slightly below the Illinois state average of 2.94%. The available water capacity of 0.190 in/in suggests a need for consistent irrigation during dry periods.
Faster Drainage for Healthier Roots
While specific drainage class data is unavailable, the high sand percentage generally points to faster water movement through the soil. Gardeners should expect the ground to dry out more quickly than in silt-heavy neighboring counties.
Hardy Crops for Zone 5b
In hardiness zone 5b, Putnam County is best suited for cold-hardy crops and traditional Midwestern staples. The sandy-silt mix is ideal for root vegetables like carrots and parsnips that thrive in looser soil.
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 Putnam County have?
Putnam County's soil is classified as Silt Loam. This indicates the relative proportions of sand, silt, and clay — 28% sand, 52% silt, and 20% clay. Loamy soils hold moisture well and support a wide range of plants.
Is Putnam County's soil acidic or alkaline?
Putnam County's soil has a pH of 6.5, which is moderately acidic. This range suits many crops and is common across much of the eastern US.
What is the drainage class for Putnam County?
Drainage class data is not currently available for Putnam County.
What crops or plants grow well in Putnam County's soil?
Based on Putnam County's Silt Loam texture, pH of 6.5, 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 Putnam County?
The dominant USDA soil order for Putnam County is not currently available in our dataset.
Planning your lawn? View lawn care data for Putnam County on LawnByCounty.com →
Other Counties in Illinois
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.