Mackinac County Soil Data
Mackinac County, Michigan
USDA SSURGO / PHZMAvg pH
4.7
Texture
Water
Drainage
N/A
Organic Matter
50.6%
Hydrologic Group
N/A
Data Story
About Soil in Mackinac County, Michigan
Highly Acidic and Silt-Rich Northern Soil
Mackinac County features an average pH of 4.66, which is significantly more acidic than the national median of 6.5 and the state average of 5.30. While taxonomic data is limited, the soil profile is characterized by its high silt content and unique water-heavy textures. This acidic environment requires specific plant selections or regular liming for traditional gardening.
Silty Profile with High Silt and Low Clay
The soil composition is dominated by 64.7% silt and 19.1% sand, with a very low clay content of only 6.7%. This high silt percentage makes the soil feel smooth and floury when dry but prone to erosion. The low clay levels mean the soil lacks the natural 'glue' needed for stable structure, though it is easy to work.
Extreme Organic Matter and High Water Capacity
The county boasts a staggering 50.58% organic matter, dwarfing the state average of 19.76% and the national average of 2.0%. This rich material contributes to an available water capacity (AWC) of 0.378 in/in, which is nearly double the state average. This combination creates a highly fertile environment that retains moisture exceptionally well.
Unmapped Drainage in Saturated Landscapes
Specific drainage and hydrologic group data are not currently available for Mackinac County's dominant soil units. However, the high organic content and silt levels suggest the landscape often holds water near the surface. Potential builders and farmers should conduct site-specific percolation tests to assess drainage before starting projects.
Cool Climate Gardening in Zone 5a
Mackinac County sits in USDA hardiness zone 5a, where short-season crops like kale, peas, and potatoes thrive. The acidic soil is naturally perfect for blueberries and rhododendrons without much amendment. Embrace the northern climate by starting your seeds indoors to get a head start on the growing season.
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: Water
Typical soil profile. Actual depths vary by location.
USDA Soil Orders
Acidic Soil Detected
Your county's average pH is 4.7. These products help balance soil pH for healthier grass.
Browse Soil AmendmentsFrequently Asked Questions
What type of soil does Mackinac County have?
Mackinac County's soil is classified as Water. This indicates the relative proportions of sand, silt, and clay — 19% sand, 65% silt, and 7% clay. Sandy soils drain quickly but may need more frequent irrigation and fertilization.
Is Mackinac County's soil acidic or alkaline?
Mackinac County's soil has a low pH of 4.7, which is strongly acidic. Acidic soils benefit from lime applications to raise pH and improve nutrient availability.
What is the drainage class for Mackinac County?
Drainage class data is not currently available for Mackinac County.
What crops or plants grow well in Mackinac County's soil?
Based on Mackinac County's Water texture, pH of 4.7, and drainage class, the soil is well suited for acid-loving plants like blueberries and azaleas.
What USDA soil order is found in Mackinac County?
The dominant USDA soil order for Mackinac County is not currently available in our dataset.
Soil & Planting Advisory: Mackinac County
Soil Verdict
Mackinac 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
Mackinac County closely matches the Michigan 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 Mackinac 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.