Knox County Soil Data
Knox County, Missouri
USDA SSURGO / PHZMAvg pH
6.4
Texture
Silt Loam
Drainage
Subaqueous
Organic Matter
2.7%
Hydrologic Group
N/A
Data Story
About Soil in Knox County, Missouri
Near-Neutral pH in Knox County
Knox County soils boast a pH of 6.41, nearly matching the national median of 6.5. This near-neutral balance is ideal for nutrient availability and reflects an impressive overall soil score of 78.4.
A Stable Silt-Clay Blend
The composition consists of 61.3% silt and 22.7% clay, with very little sand at 15.9%. This mix provides a stable, dense medium that prevents fertilizers from leaching away too quickly.
Top-Tier Water Holding Capacity
At 0.213 in/in, the available water capacity is among the best in the state, far exceeding the 0.183 in/in average. The organic matter content is 2.66%, offering a healthy foundation for diverse agricultural uses.
Navigating Subaqueous Soil Records
Dominant records indicate subaqueous drainage, meaning these soils are frequently saturated or underwater. Proper site selection is critical in Knox County to ensure garden beds have the drainage they need to thrive.
Hardy Crops for Zone 6a
The colder winters of Zone 6a are perfect for hardy root vegetables and berries. This county's excellent water capacity and neutral pH provide a premium environment for any aspiring gardener.
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
Subaqueous
Drainage class: Subaqueous
Soil Profile
Dominant texture: Silt Loam
Typical soil profile. Actual depths vary by location.
USDA Soil Orders
Soil Amendment Products
Browse products to improve your soil health and lawn performance.
Browse Soil AmendmentsFrequently Asked Questions
What type of soil does Knox County have?
Knox County's soil is classified as Silt Loam. This indicates the relative proportions of sand, silt, and clay — 16% sand, 61% silt, and 23% clay. Loamy soils hold moisture well and support a wide range of plants.
Is Knox County's soil acidic or alkaline?
Knox County's soil has a pH of 6.4, which is moderately acidic. This range suits many crops and is common across much of the eastern US.
What is the drainage class for Knox County?
Knox County has a dominant drainage class of "Subaqueous." Moderate drainage allows adequate moisture retention while still permitting excess water to drain over time.
What crops or plants grow well in Knox County's soil?
Based on Knox County's Silt Loam texture, pH of 6.4, and Subaqueous, the soil is well suited for vegetables, grains, and most field crops, row crops and vegetable gardens.
What USDA soil order is found in Knox County?
The dominant USDA soil order for Knox County is not currently available in our dataset.
Soil & Planting Advisory: Knox County
Soil Verdict
Knox County is in USDA hardiness zone 6a, a moderate climate zone. where winter lows can reach -10°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
Knox County closely matches the Missouri average hardiness conditions.
Planning your lawn? View lawn care data for Knox County on LawnByCounty.com →
Other Counties in Missouri
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.