Polk County Soil Data
Polk County, Minnesota
USDA SSURGO / PHZMAvg pH
6.7
Texture
Loam
Drainage
N/A
Organic Matter
12.5%
Hydrologic Group
N/A
Data Story
About Soil in Polk County, Minnesota
Polk's High-Performing Neutral Soil
Polk County features a strong soil score of 84.4, well above the state average of 73.0. Its average pH of 6.71 is near neutral, sitting slightly higher than the national median of 6.5. This balanced chemistry makes it one of the more versatile counties for Minnesota agriculture.
Sandy Texture with Moderate Clay
The soil contains 45.3% sand, 35.5% silt, and 15.7% clay. This high sand percentage ensures the ground warms up quickly in the spring and remains easy to till. The moderate clay levels provide just enough structure to keep the soil from eroding too easily.
Abundant Organic Matter and Moisture
With 12.52% organic matter, Polk exceeds the state average of 9.90% and dwarfs the national average of 2.0%. Its available water capacity of 0.198 in/in is almost exactly the state benchmark. This combination ensures plants have access to both rich nutrients and consistent moisture.
Aerated and Absorbent Ground
Though no official drainage class is recorded, the 45.3% sand content points toward efficient natural drainage and good aeration. The soil's ability to hold 0.198 inches of water per inch of soil helps buffer against dry spells. This mix is generally favorable for large-scale farming and home gardening alike.
Diverse Potential in Zone 4a
Falling in Zone 4a, Polk is a prime location for cool-season crops and wheat. The high organic matter and neutral pH support everything from vibrant flower beds to productive vegetable patches. Residents should feel confident starting a garden in this high-scoring, nutrient-rich 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: 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 Polk County have?
Polk County's soil is classified as Loam. This indicates the relative proportions of sand, silt, and clay — 45% sand, 36% silt, and 16% clay. Loamy soils hold moisture well and support a wide range of plants.
Is Polk County's soil acidic or alkaline?
Polk County's soil has a pH of 6.7, which is near neutral. This range is ideal for most garden plants and field crops.
What is the drainage class for Polk County?
Drainage class data is not currently available for Polk County.
What crops or plants grow well in Polk County's soil?
Based on Polk County's Loam texture, pH of 6.7, 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 Polk County?
The dominant USDA soil order for Polk County is not currently available in our dataset.
Soil & Planting Advisory: Polk County
Soil Verdict
Polk County is in USDA hardiness zone 4a, a cold climate zone. where winter lows can reach -30°F. Soils here experience deep freeze cycles that can disrupt structure, kill shallow roots, and slow microbial activity for months each year.
Planting Guidance
Focus on cold-hardy perennials, native grasses, and conifers. The short growing window favors plants with low heat requirements. 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
Deep winter freezing can create soil heaving that pushes shallow-rooted plants out of the ground; add 3-4 inches of organic mulch each fall. Soil drainage is critical — frozen, waterlogged soil kills roots faster than cold alone. When soil temperatures drop below freezing, microbial nitrogen cycling stops; spring fertilization is more effective than late-fall application.
Regional Context
Polk County closely matches the Minnesota average hardiness conditions. The zone range of 3b-4a within the county means soil and planting decisions should account for local elevation and topography.
Planning your lawn? View lawn care data for Polk 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.