St. Charles Parish Soil Data
St. Charles Parish, Louisiana
USDA SSURGO / PHZMAvg pH
5.8
Texture
Clay
Drainage
N/A
Organic Matter
20.5%
Hydrologic Group
N/A
Data Story
About Soil in St. Charles Parish, Louisiana
Acidic and Organic Deep Soils
St. Charles Parish averages a soil pH of 5.76, aligning almost perfectly with the Louisiana state average of 5.74. This level is more acidic than the national median of 6.5, typical for high-organic wetlands. These soils are chemically active and reflect the parish's unique river-delta geography.
A Clay-Dominant Landscape
This soil is composed of 47.7% clay and a tiny 4.1% sand fraction, creating a very heavy texture. Such high clay levels mean the soil holds onto nutrients and water with extreme tenacity. However, this also makes it prone to shrinking and swelling, which affects both gardening and construction.
Massive Organic Matter Reserves
The organic matter content is an incredible 20.48%, which is more than ten times the national average. This high carbon level, combined with a water capacity of 0.210 in/in, creates a spongy, highly fertile environment. This soil acts as a massive reservoir for both moisture and plant nutrients.
High Capacity for Moisture
Although specific drainage classes are not listed, the low sand and high organic matter ensure the soil remains saturated for long periods. The soil acts like a sponge, holding 0.210 inches of water per inch of soil. This requires careful management of drainage to prevent anaerobic conditions for plant roots.
Tropical Potential in Zone 9b
In the mild winters of zone 9b, you can grow satsumas, papayas, and ginger with ease. The high-clay, high-organic soil is a dream for moisture-loving plants like hibiscus and cannas. Start your backyard oasis today and enjoy the incredible natural fertility of the delta.
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: Clay
Typical soil profile. Actual depths vary by location.
USDA Soil Orders
Acidic Soil Detected
Your county's average pH is 5.8. These products help balance soil pH for healthier grass.
Browse Soil AmendmentsFrequently Asked Questions
What type of soil does St. Charles Parish have?
St. Charles Parish's soil is classified as Clay. This indicates the relative proportions of sand, silt, and clay — 4% sand, 32% silt, and 48% clay. Clay soils retain water and nutrients but can have drainage challenges.
Is St. Charles Parish's soil acidic or alkaline?
St. Charles Parish's soil has a pH of 5.8, which is moderately acidic. This range suits many crops and is common across much of the eastern US.
What is the drainage class for St. Charles Parish?
Drainage class data is not currently available for St. Charles Parish.
What crops or plants grow well in St. Charles Parish's soil?
Based on St. Charles Parish's Clay texture, pH of 5.8, and drainage class, the soil is well suited for vegetables, grains, and most field crops, wetland plants and crops tolerant of slow drainage.
What USDA soil order is found in St. Charles Parish?
The dominant USDA soil order for St. Charles Parish is not currently available in our dataset.
Soil & Planting Advisory: St. Charles Parish
Soil Verdict
St. Charles Parish is in USDA hardiness zone 9b, a warm climate zone. where winter lows can reach 25°F. Warm winters keep soil biology active nearly year-round, accelerating decomposition but increasing pest and disease pressure in topsoil.
Planting Guidance
Tropical and subtropical plants are viable. Year-round gardening is possible, though summer heat may limit some cool-season crops. Frost is rare; tender plants can overwinter with minimal 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
Rapid organic matter turnover means soils can become nutrient-poor quickly; test annually and fertilize based on results. High soil temperatures favor certain soilborne pathogens; practice crop rotation and avoid overwatering.
Regional Context
St. Charles Parish closely matches the Louisiana average hardiness conditions.
Planning your lawn? View lawn care data for St. Charles Parish on LawnByCounty.com →
Other Counties in Louisiana
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.