County soil summary

Soil types in Howard County, Maryland

The most widespread soils are Glenelg, Manor and Glenville; the most common drainage class is well drained (64% of the land), and typical topsoil pH is 5.4.

Mapped soil survey data 161,000 acres of mapped land · 40 named soil series

Well or moderately well drained
80%
of land · state 70%
Typical topsoil pH
5.4
strongly acidic · state 5.4
Septic fields very limited
77%
of land · state 85%
Subject to flooding
6%
of land, any frequency · state 10%

Most common soils in Howard County

Share of mapped land

A county is a patchwork of many soils. These 8 cover 76% of the mapped land; 40 named soil series are mapped here in all.

Most common soils in Howard County by share of mapped land
Soil Share of land Drainage Topsoil pH
Glenelg 25.6% Well drained 5.4
Manor 12.5% Well drained 5.3
Glenville 9.7% Moderately well drained 6.8
Gladstone 9.0% Well drained 6.3
Urban landLand type, not a soil series 7.1% — —
UdorthentsGeneral soil group, not a named series 5.5% — —
Baile 3.4% Poorly drained 5.2
Codorus 2.8% Somewhat poorly drained 5.3

Drainage and pH for a series are its typical values across all its mapped acres nationwide. A dash means the row is not a soil series.

What this means

What the soils in Howard County mean for gardens, lawns and septic systems

For your garden

Typical topsoil in Howard County is strongly acidic: pH 5.4 (most land between 5.2 and 6.1). Most vegetables and lawn grasses do best around 6.0 to 7.0, so lime is often needed; blueberries, azaleas and rhododendrons like it as it is.

Loamy topsoil (loam, silt loam and similar) covers 88% of the land: generally the easiest soil to garden, holding moisture without staying waterlogged. The most common surface texture is loam (52% of the land).

80% of the land is moderately well to excessively drained, which suits most garden plants.

For your lawn and yard

Most land is in hydrologic groups B and C, where rain soaks in at a moderate pace.

For a septic system

For conventional septic absorption fields, NRCS rates 77% of the land in Howard County very limited, 12% somewhat limited and 0% not limited (11% not rated, such as urban land, pits or water).

Statewide, 85% of the land is very limited, so Howard County is less restrictive than typical.

Where the soil is very limited (slow permeability, a high water table, flooding, shallow bedrock or steep slopes), alternative systems such as mound or sand-filter designs are common and cost more.

Flooding is mapped on 6% of the land (3% occasional, 3% frequent).

Only a licensed site evaluation or perc test at the actual lot decides whether a system is allowed and which design.

Generated from the mapped numbers above using fixed rules, not a site visit. See how these notes are written.

Drainage

How long the soil stays wet

The most common drainage class is well drained (64%). 80% of the land is moderately well drained or better, compared with 70% across Maryland.

Excessively drained <1%
Somewhat excessively drained 1%
Well drained 64%
Moderately well drained 15%
Somewhat poorly drained 2%
Poorly drained 7%
Very poorly drained 0%
Not rated 11%
Natural drainage class, share of mapped land in Howard County. Scale 0 to 100% of mapped land.
Show as a table
Natural drainage class, share of mapped land in Howard County.
CategoryHoward CountyMaryland
Excessively drained0.2%1.3%
Somewhat excessively drained1.0%1.9%
Well drained64.3%48.1%
Moderately well drained14.7%18.2%
Somewhat poorly drained1.8%4.5%
Poorly drained7.3%12.9%
Very poorly drained0.0%6.3%
Not rated10.7%6.8%

Septic absorption fields

NRCS rating for conventional drain fields

The rating looks at the soil from 24 to 60 inches deep: permeability, depth to a seasonal water table or bedrock, flooding and slope. “Very limited” means at least one feature is unfavorable enough that a conventional field is hard to make work.

Not limited 0%
Somewhat limited 12%
Very limited 77%
Not rated 11%
Septic tank absorption field rating, share of mapped land in Howard County. Scale 0 to 100% of mapped land.
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Septic tank absorption field rating, share of mapped land in Howard County.
CategoryHoward CountyMaryland
Not limited0.0%0.5%
Somewhat limited12.4%7.6%
Very limited77.0%85.4%
Not rated10.6%6.5%

Rain, runoff and water table

Hydrologic soil group, flooding, seasonal water table

Hydrologic soil group

How fast rain soaks in when the soil is already wet. Group A soaks in fastest, D slowest.

A: fast infiltration (mostly sandy or gravelly) 9%
B: moderate infiltration 46%
C: slow infiltration 21%
D: very slow infiltration (clayey, shallow or wet) 8%
A/D: D as is, A if drained 0%
B/D: D as is, B if drained 3%
C/D: D as is, C if drained 10%
Not rated 4%
Hydrologic soil group, share of mapped land in Howard County. Scale 0 to 100% of mapped land.
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Hydrologic soil group, share of mapped land in Howard County.
CategoryHoward CountyMaryland
A: fast infiltration (mostly sandy or gravelly)9.0%10.9%
B: moderate infiltration45.6%26.7%
C: slow infiltration20.7%25.7%
D: very slow infiltration (clayey, shallow or wet)8.0%11.6%
A/D: D as is, A if drained0.0%4.5%
B/D: D as is, B if drained2.9%5.3%
C/D: D as is, C if drained9.9%12.8%
Not rated3.9%2.5%

Flooding

No flooding 91%
Rare or very rare 0%
Occasional 3%
Frequent or very frequent 3%
Not reported 4%
Most frequent flooding class in any month, share of mapped land in Howard County. Scale 0 to 100% of mapped land.
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Most frequent flooding class in any month, share of mapped land in Howard County.
CategoryHoward CountyMaryland
No flooding90.6%86.8%
Rare or very rare0.0%0.2%
Occasional2.7%2.6%
Frequent or very frequent2.8%7.5%
Not reported3.8%2.9%

Seasonal high water table

Within 18 inches at some time of year 9%
18 inches to 3.3 feet 15%
Deeper than 3.3 feet or none reported 73%
Not reported 4%
Shallowest depth to a saturated zone in any month, share of mapped land in Howard County. Scale 0 to 100% of mapped land.
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Shallowest depth to a saturated zone in any month, share of mapped land in Howard County.
CategoryHoward CountyMaryland
Within 18 inches at some time of year8.5%25.1%
18 inches to 3.3 feet15.0%18.9%
Deeper than 3.3 feet or none reported72.6%53.1%
Not reported3.8%2.8%

Topsoil pH and texture

First mineral layer of each soil

Typical topsoil pH is 5.4 (strongly acidic); 80% of rated land falls between 5.2 and 6.1. Median topsoil organic matter is 2.5%.

Strongly acidic (below 5.5) 48%
Moderately to slightly acidic (5.5–6.4) 35%
Near neutral (6.5–7.3) 6%
Alkaline (7.4 and up) 0%
Not reported 11%
Topsoil pH band, share of mapped land in Howard County. Scale 0 to 100% of mapped land.
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Topsoil pH band, share of mapped land in Howard County.
CategoryHoward CountyMaryland
Strongly acidic (below 5.5)48.2%50.9%
Moderately to slightly acidic (5.5–6.4)35.0%33.6%
Near neutral (6.5–7.3)6.1%7.0%
Alkaline (7.4 and up)0.0%1.1%
Not reported10.7%7.5%

Texture

Sandy <1%
Loamy (loam, silt loam and similar) 88%
Clayey (40%+ clay) 0%
Organic (muck or peat) <1%
Not reported (rock, urban land, etc.) 11%
Topsoil texture group, share of mapped land in Howard County. Scale 0 to 100% of mapped land.
Show as a table
Topsoil texture group, share of mapped land in Howard County.
CategoryHoward CountyMaryland
Sandy0.4%9.5%
Loamy (loam, silt loam and similar)88.4%78.4%
Clayey (40%+ clay)0.0%0.0%
Organic (muck or peat)0.5%5.8%
Not reported (rock, urban land, etc.)10.7%6.3%

Most common surface textures: loam 52% · silt loam 24% · gravelly silt loam 4% · sandy loam 4% · channery loam 3%.

Sources & data dates

Source
USDA NRCS Soil Survey Geographic Database (SSURGO), queried through Soil Data Access. Public domain.
Data date
SSURGO as published on November 3, 2026 (most recent survey area update October 26, 2026). NRCS refreshes SSURGO each October.
Scope
Howard County, Maryland (FIPS 24027): 160,719 acres of mapped land, 1,381 acres of open water excluded. State comparisons pool all mapped land in Maryland.
Method
Shares are by mapped land area: each map unit’s acres in the county times each soil component’s percentage. Open water is excluded. Topsoil values use the first mineral horizon of each component. Full methodology.

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