Soil series profile

Gilwood soil series

Gilwood is a well drained soil with a silt loam surface, mapped on 93,162 acres in 11 counties in IN. Hydrologic group C.

#3739 by mapped area fine-loamy Typic Hapludults (Ultisols)

Drainage class: Well drained
Hydrologic group: C
Typical topsoil pH: 5.5
Mapped area: 93k

Typical Gilwood profile

Texture and pH by depth

Depth to scale. More strongly shaded layers hold more clay. Horizon names are the soil survey's (A = topsoil, B = subsoil, C = parent material).

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Typical Gilwood horizons (representative values)
Depth	Texture	pH	Clay	Sand	Organic matter
0–6 in (A)	Silt loam	5.5	15%	8%	3%
6–11 in (BE)	Channery silt loam	5.0	19%	8%	0.75%
11–22 in (Bt)	Channery silt loam	4.6	23%	11%	0.25%
22–32 in (CB)	Extremely channery silt loam	4.6	18%	18%	0.25%
32–42 in (R)	Bedrock	Not reported	Not reported	Not reported	Not reported

Representative values from the most extensive Gilwood map unit (Brownstown-Gilwood silt loams, 25 to 75 percent slopes, survey area IN105). Other map units of this series vary within the series range.

Stock photo for illustration, not a sample of this soil series. Credit on the Sources & method page.

What this means

What Gilwood soil means for gardens, lawns and septic systems

For gardens

Typical topsoil in Gilwood soils is strongly acidic: pH 5.5 (most land between 5.1 and 5.5). 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 100% of mapped Gilwood acres: generally the easiest soil to garden, holding moisture without staying waterlogged. The most common surface texture is silt loam (100% of mapped Gilwood acres).

100% of mapped Gilwood acres is moderately well to excessively drained, which suits most garden plants.

For lawns and yards

On 100% of mapped acres, rain soaks in slowly (hydrologic groups C and D, including dual groups that are D until drained). Expect runoff and puddles after heavy rain: core-aerate compacted lawns and keep ground sloping away from foundations.

For a septic system

For conventional septic absorption fields, NRCS rates 100% of the acres in mapped Gilwood soils very limited, 0% somewhat limited and 0% not limited.

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.

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.

Where Gilwood soil is found

Mapped acres

Gilwood is mapped in Indiana.

Counties with the most mapped Gilwood soil
County	Acres	Share of county land
Monroe County, IN	34,670	13.8%
Lawrence County, IN	15,139	5.3%
Washington County, IN	12,629	3.8%
Jackson County, IN	10,132	3.1%
Floyd County, IN	7,570	8.0%
Clark County, IN	6,599	2.8%
Bartholomew County, IN	3,854	1.5%
Scott County, IN	950	0.8%
Brown County, IN	868	0.4%
Harrison County, IN	700	0.2%
Johnson County, IN	50	0.0%

Septic absorption fields

NRCS rating, share of Gilwood acres

Not limited 0%

Somewhat limited 0%

Very limited 100%

Septic tank absorption field rating across mapped Gilwood acres. Scale 0 to 100% of mapped land.

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Septic tank absorption field rating across mapped Gilwood acres.
Category	Share of acres
Not limited	0.0%
Somewhat limited	0.0%
Very limited	100.0%

Drainage, water table and flooding

Share of Gilwood acres

Depth to seasonal high water table: None reported within about 6.5 feet (median where reported).
Flooding: Not mapped as flooding on most acres.
Slope: Typically 15–38% (median 38%).
Topsoil organic matter: Median 3%.

Drainage class

Excessively drained 0%

Somewhat excessively drained 0%

Well drained 100%

Moderately well drained 0%

Somewhat poorly drained 0%

Poorly drained 0%

Very poorly drained 0%

Drainage class across mapped Gilwood acres. Scale 0 to 100% of mapped land.

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Drainage class across mapped Gilwood acres.
Category	Share of acres
Excessively drained	0.0%
Somewhat excessively drained	0.0%
Well drained	100.0%
Moderately well drained	0.0%
Somewhat poorly drained	0.0%
Poorly drained	0.0%
Very poorly drained	0.0%

Hydrologic soil group

A: fast infiltration (mostly sandy or gravelly) 0%

B: moderate infiltration 0%

C: slow infiltration 100%

D: very slow infiltration (clayey, shallow or wet) 0%

A/D: D as is, A if drained 0%

B/D: D as is, B if drained 0%

C/D: D as is, C if drained 0%

Hydrologic soil group across mapped Gilwood acres. Scale 0 to 100% of mapped land.

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Hydrologic soil group across mapped Gilwood acres.
Category	Share of acres
A: fast infiltration (mostly sandy or gravelly)	0.0%
B: moderate infiltration	0.0%
C: slow infiltration	100.0%
D: very slow infiltration (clayey, shallow or wet)	0.0%
A/D: D as is, A if drained	0.0%
B/D: D as is, B if drained	0.0%
C/D: D as is, C if drained	0.0%

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: All map unit components named Gilwood (component kind "Series") in SSURGO: 93,162 acres.
Method: Shares are by mapped acres of Gilwood components. The profile comes from the single largest Gilwood component. Full methodology.

Independent reference site. No government affiliation or endorsement.

Full narrative description: USDA Official Soil Series Description for Gilwood.