Grundy County Soil Data
Grundy County, Illinois
USDA SSURGO / PHZMAvg pH
6.6
Texture
Silt Loam
Drainage
N/A
Organic Matter
3.6%
Hydrologic Group
N/A
Data Story
About Soil in Grundy County, Illinois
Grundy's High pH Potential
Grundy County has a pH of 6.63, the highest among this group and well above the national median of 6.5. This near-neutral acidity is ideal for most commercial crops and diverse home gardens.
Grittier Mix for Better Tilling
This soil has a higher sand content than its neighbors at 25.1%, mixed with 51.0% silt and 23.3% clay. This unique composition improves aeration and makes the soil easier to till in the spring.
Elite Organic Matter Levels
The organic matter is impressive at 3.60%, far surpassing the Illinois state average of 2.94%. However, the available water capacity of 0.187 in/in is lower than the state average of 0.204.
Natural Aeration and Water Flow
Local records are limited, but the relatively high sand content suggests better natural drainage than heavier clay soils found elsewhere. This profile helps oxygen reach plant roots, though it may require more frequent watering.
Cold-Hardy Growth in Zone 5b
Falling into the cooler Zone 5b, Grundy County is perfect for cold-hardy perennials and early-season greens. Take advantage of the high organic matter to grow nutrient-dense vegetables right in your backyard.
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
Soil Amendment Products
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Browse Soil AmendmentsFrequently Asked Questions
What type of soil does Grundy County have?
Grundy County's soil is classified as Silt Loam. This indicates the relative proportions of sand, silt, and clay — 25% sand, 51% silt, and 23% clay. Loamy soils hold moisture well and support a wide range of plants.
Is Grundy County's soil acidic or alkaline?
Grundy County's soil has a pH of 6.6, which is near neutral. This range is ideal for most garden plants and field crops.
What is the drainage class for Grundy County?
Drainage class data is not currently available for Grundy County.
What crops or plants grow well in Grundy County's soil?
Based on Grundy County's Silt Loam texture, pH of 6.6, 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 Grundy County?
The dominant USDA soil order for Grundy County is not currently available in our dataset.
Soil & Planting Advisory: Grundy County
Soil Verdict
Grundy County is in USDA hardiness zone 5b, a cold climate zone. where winter lows can reach -15°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
Grundy County is somewhat cooler than the Illinois statewide average.
Planning your lawn? View lawn care data for Grundy 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.