Rock County Soil Data
Rock County, Minnesota
USDA SSURGO / PHZMAvg pH
6.8
Texture
Silty Clay Loam
Drainage
N/A
Organic Matter
4.5%
Hydrologic Group
N/A
Data Story
About Soil in Rock County, Minnesota
Alkaline Soils in the Southwest
Rock County’s soil pH sits at 6.83, which is more alkaline than the national median of 6.5. This measurement is significantly higher than the Minnesota average of 6.21. Such levels are generally favorable for legumes and many common row crops.
Dominant Silt and Clay Mix
The soil is predominantly silt at 54.3%, with 27.7% clay and a low 18.0% sand content. This fine-textured mix allows the soil to hold nutrients and water very effectively. However, the high silt and clay levels mean the ground may become heavy when wet.
Steady Moisture for Growing Plants
The organic matter content is 4.46%, which is double the national average but below the state average of 9.90%. The available water capacity of 0.201 in/in stays just above the state benchmark of 0.199. This ensures a consistent water supply for crops throughout the growing season.
Solid Soil Performance Ratings
A soil score of 75.1 puts Rock County above the state average of 73.0. The high silt percentage suggests that drainage may be slower than in sandier neighboring counties. Proper management can prevent compaction and ensure long-term soil health.
Ideal Conditions in Zone 5a
Located in Zone 5a, Rock County enjoy a slightly warmer climate than most of Minnesota. This allows for a wider variety of vegetables and a longer season for corn and small grains. Your garden will thrive in this nutrient-dense silty 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: Silty Clay Loam
Typical soil profile. Actual depths vary by location.
USDA Soil Orders
Clay Soil Detected
Clay soils can struggle with drainage. These products improve soil structure and water flow.
Browse Soil AmendmentsFrequently Asked Questions
What type of soil does Rock County have?
Rock County's soil is classified as Silty Clay Loam. This indicates the relative proportions of sand, silt, and clay — 18% sand, 54% silt, and 28% 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 6.8, which is near neutral. This range is ideal for most garden plants and field crops.
What is the drainage class for Rock County?
Drainage class data is not currently available for Rock County.
What crops or plants grow well in Rock County's soil?
Based on Rock County's Silty Clay Loam texture, pH of 6.8, 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 Rock County?
The dominant USDA soil order for Rock County is not currently available in our dataset.
Soil & Planting Advisory: Rock County
Soil Verdict
Rock County is in USDA hardiness zone 5a, a cold climate zone. where winter lows can reach -20°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. With extreme winter lows, any marginally hardy plants need heavy mulch and wind protection. 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 is somewhat warmer than the Minnesota statewide average. The zone range of 4b-5a 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 Minnesota
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.