Washtenaw County Soil Data
Washtenaw County, Michigan
USDA SSURGO / PHZMAvg pH
6.1
Texture
Sandy Loam
Drainage
N/A
Organic Matter
8.3%
Hydrologic Group
N/A
Data Story
About Soil in Washtenaw County, Michigan
Moderately Acidic Soils in Washtenaw
Washtenaw's soil features a pH of 6.09, which is more acidic than the national median of 6.5 but significantly less acidic than the Michigan state average of 5.30. While specific taxonomic data is limited for this region, the county earns a strong soil score of 68.7. This score comfortably exceeds the state average of 60.5, indicating high-quality earth for local use.
A Sandy Foundation with Silt
The soil composition is primarily sand at 54.6%, complemented by 26.5% silt and 15.2% clay. This mixture creates a stable physical structure that is relatively easy to work during the spring planting season. The sand-heavy profile ensures that the ground doesn't become overly compacted, though it requires careful management of moisture.
Strong Organic Matter Levels
At 8.27%, the organic matter content far exceeds the national average of 2.0%, though it sits below the state average of 19.76%. The available water capacity is 0.174 in/in, slightly trailing the state benchmark of 0.202 in/in. These figures suggest a fertile environment that may require supplemental irrigation during dry Midwestern summers.
Naturally Porous Landscape Trends
While specific drainage classes are not recorded in this dataset, the high sand percentage typically indicates naturally rapid water movement. This characteristic is generally beneficial for building foundations but means nutrients can leach away more quickly than in clay-heavy soils. Gardeners should plan for frequent, light watering to keep plants hydrated.
Thriving in Hardiness Zone 6a
Washtenaw County sits in USDA Hardiness Zone 6a, a versatile zone for everything from tomatoes to fruit trees. The combination of sandy textures and moderate pH levels makes this an excellent region for diverse agricultural pursuits. Now is a great time to start a garden and take advantage of these above-average Michigan soils.
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: Sandy Loam
Typical soil profile. Actual depths vary by location.
USDA Soil Orders
Sandy Soil Detected
Sandy soils drain quickly and can dry out. These products boost water retention and organic matter.
Browse Soil AmendmentsFrequently Asked Questions
What type of soil does Washtenaw County have?
Washtenaw County's soil is classified as Sandy Loam. This indicates the relative proportions of sand, silt, and clay — 55% sand, 27% silt, and 15% clay. Loamy soils hold moisture well and support a wide range of plants.
Is Washtenaw County's soil acidic or alkaline?
Washtenaw County's soil has a pH of 6.1, which is moderately acidic. This range suits many crops and is common across much of the eastern US.
What is the drainage class for Washtenaw County?
Drainage class data is not currently available for Washtenaw County.
What crops or plants grow well in Washtenaw County's soil?
Based on Washtenaw County's Sandy Loam texture, pH of 6.1, 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 Washtenaw County?
The dominant USDA soil order for Washtenaw County is not currently available in our dataset.
Soil & Planting Advisory: Washtenaw County
Soil Verdict
Washtenaw 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
Washtenaw County is somewhat warmer than the Michigan statewide average.
Planning your lawn? View lawn care data for Washtenaw County on LawnByCounty.com →
Other Counties in Michigan
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.