District of Columbia Soil Data
District of Columbia, District of Columbia
USDA SSURGO / PHZMAvg pH
5.3
Texture
Silt loam
Drainage
Well drained
Organic Matter
2.3%
Hydrologic Group
C
Data Story
About Soil in District of Columbia, District of Columbia
Acidic Ultisols Define the Capital's Ground
The District's soil consists primarily of Ultisols with a dominant silt loam texture. At 5.27, the average pH is significantly more acidic than the national median of 6.5, mirroring the regional baseline exactly.
A Balanced Mix of Sand and Silt
With 51.1% sand and 34.9% silt, this soil offers a gritty but workable texture for urban landscapes. The relatively low 13.4% clay content prevents heavy compaction while still providing enough structure for root stability.
Healthy Organic Matter for Urban Growing
Organic matter levels reach 2.30%, which exceeds the national average of 2.0%. Combined with an available water capacity of 0.154 in/in, the soil provides a steady, fertile foundation for city gardens and parklands.
Efficient Drainage Meets Dense Subsoil
The land is categorized as well-drained, yet it falls into Hydrologic Group C, indicating a slow rate of water transmission when saturated. This combination means surface water clears quickly, but the deeper layers may resist rapid infiltration during heavy storms.
Thriving in the Capital's Zone 7b
D.C.’s 7b hardiness zone is perfect for growing heat-tolerant greens, azaleas, and even fig trees in the acidic silt loam. Whether you are planting a community plot or a balcony box, the District's soil is ready for your next urban garden project.
Soil Composition
Soil pH
Soil Series
Detailed soil series data not yet available for this county.
Hydrologic Group
Group C — Moderate-High Runoff
Soils with slow infiltration rates, often with a layer that impedes downward water movement. Higher clay content restricts drainage.
Drainage Class
Well drained
Water is removed from the soil readily but not rapidly. Optimal for most plants and construction.
Soil Profile
Dominant texture: Silt loam
Typical soil profile. Actual depths vary by location.
USDA Soil Orders
Acidic Soil Detected
Your county's average pH is 5.3. These products help balance soil pH for healthier grass.
Browse Soil AmendmentsFrequently Asked Questions
What type of soil does District of Columbia have?
District of Columbia's soil is classified as Silt loam. This indicates the relative proportions of sand, silt, and clay — 51% sand, 35% silt, and 13% clay. Loamy soils hold moisture well and support a wide range of plants.
Is District of Columbia's soil acidic or alkaline?
District of Columbia's soil has a low pH of 5.3, which is strongly acidic. Acidic soils benefit from lime applications to raise pH and improve nutrient availability.
What is the drainage class for District of Columbia?
District of Columbia has a dominant drainage class of "Well drained." Well-drained soils allow excess water to move through quickly, reducing waterlogging risk and supporting most field and garden crops.
What crops or plants grow well in District of Columbia's soil?
Based on District of Columbia's Silt loam texture, pH of 5.3, and Well drained, the soil is well suited for acid-loving plants like blueberries and azaleas, row crops and vegetable gardens, most annual and perennial crops.
What USDA soil order is found in District of Columbia?
District of Columbia's dominant soil order is Ultisols. Ultisols are highly weathered, clay-rich soils common in humid regions. They are low in natural fertility and often require lime and fertilizer for agriculture.
Soil & Planting Advisory: District of Columbia
Soil Verdict
District of Columbia is in USDA hardiness zone 7b, a moderate climate zone. where winter lows can reach 5°F. Mild winters mean soil rarely freezes deeply, allowing year-round microbial activity and faster organic matter breakdown.
Planting Guidance
Warm-season crops, citrus relatives, and heat-loving ornamentals do well. Cool-season vegetables should be planted in fall and winter. 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
Warm soils accelerate organic matter breakdown, so compost and mulch need replenishing more frequently than in cooler zones. Sandy soils common in warm zones drain quickly; water-retentive amendments like compost or peat help hold moisture.
Regional Context
District of Columbia closely matches the District of Columbia average hardiness conditions. The zone range of 7b-8a within the county means soil and planting decisions should account for local elevation and topography.
Planning your lawn? View lawn care data for District of Columbia on LawnByCounty.com →
Other Counties in District of Columbia
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.