Rock County Soil Data
Rock County, Wisconsin
USDA SSURGO / PHZMAvg pH
6.2
Texture
Loam
Drainage
Well drained
Organic Matter
4.7%
Hydrologic Group
B
Data Story
About Soil in Rock County, Wisconsin
Top-tier agricultural soils in Rock County
Rock County features Alfisols with a loam texture and a pH of 6.18, the highest in this group. This approaches the national median of 6.5 and is much more alkaline than the Wisconsin average of 5.63.
The ideal loam for diverse farming
The soil contains 40.8% silt, 38.2% sand, and 16.5% clay. This 'Goldilocks' mix provides excellent drainage, good aeration, and high nutrient-holding capacity for local farmers.
Wisconsin's leading soil health score
Rock County earns an impressive soil score of 75.2, well above the state average of 68.2. While organic matter is 4.67%, the soil's structure and 0.198 in/in water capacity make it highly productive.
Reliable drainage for development and crops
The soil is well-drained and belongs to hydrologic group B. These conditions are perfect for maintaining healthy root systems and providing stable ground for building projects.
Maximum productivity in Zone 5b
With a 5b hardiness zone and high-quality loam, Rock County is a gardener's paradise. You can successfully grow everything from corn to delicate flowering perennials in this prime soil.
Soil Composition
Soil pH
Soil Series
Detailed soil series data not yet available for this county.
Hydrologic Group
Group B — Moderate Runoff
Moderately deep, moderately well-drained soils with moderate infiltration rates. Good balance of drainage and water retention.
Drainage Class
Well drained
Water is removed from the soil readily but not rapidly. Optimal for most plants and construction.
Soil Profile
Dominant texture: Loam
Typical soil profile. Actual depths vary by location.
USDA Soil Orders
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Browse Soil AmendmentsFrequently Asked Questions
What type of soil does Rock County have?
Rock County's soil is classified as Loam. This indicates the relative proportions of sand, silt, and clay — 38% sand, 41% silt, and 17% clay. Loamy soils hold moisture well and support a wide range of plants.
Is Rock County's soil acidic or alkaline?
Rock County's soil has a pH of 6.2, which is moderately acidic. This range suits many crops and is common across much of the eastern US.
What is the drainage class for Rock County?
Rock County has a dominant drainage class of "Well drained." Well-drained soils allow excess water to move through quickly, reducing waterlogging risk and supporting most field and garden crops.
What crops or plants grow well in Rock County's soil?
Based on Rock County's Loam texture, pH of 6.2, and Well drained, the soil is well suited for vegetables, grains, and most field crops, row crops and vegetable gardens, most annual and perennial crops.
What USDA soil order is found in Rock County?
Rock County's dominant soil order is Alfisols. Alfisols are moderate to high base-status soils with a clay-enriched subsoil. They support productive forests and cropland across temperate regions.
Soil & Planting Advisory: Rock County
Soil Verdict
Rock 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
Rock County closely matches the Wisconsin average hardiness conditions. The zone range of 5a-5b within the county means soil and planting decisions should account for local elevation and topography.
Planning your lawn? View lawn care data for Rock County on LawnByCounty.com →
Other Counties in Wisconsin
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.