Soil series profile

Shedd soil series

Shedd is a well drained soil with a silt loam surface, mapped on 154,500 acres in 7 counties in CA. Hydrologic group C.

#2390 by mapped area fine-silty Typic Xerorthents (Entisols)

Drainage class: Well drained
Hydrologic group: C
Typical topsoil pH: 8.2
Mapped area: 155k

Typical Shedd 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 Shedd horizons (representative values)
Depth	Texture	pH	Clay	Sand	Organic matter
0–30 in (H1)	Silt loam	8.2	26%	9%	3%
30–34 in (H2)	Bedrock	Not reported	Not reported	Not reported	Not reported

Representative values from the most extensive Shedd map unit (Shedd silt loam, 30 to 75 percent slopes, severely eroded, survey area CA053). 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 Shedd soil means for gardens, lawns and septic systems

For gardens

Typical topsoil in Shedd soils is moderately alkaline: pH 8.2 (most land between 8.0 and 8.2). Acid-loving plants such as blueberries and azaleas struggle without amended beds, and some trees and shrubs show iron chlorosis (yellow leaves with green veins).

Loamy topsoil (loam, silt loam and similar) covers 93% of mapped Shedd acres: generally the easiest soil to garden, holding moisture without staying waterlogged. The most common surface texture is silty clay loam (62% of mapped Shedd acres).

93% of mapped Shedd acres is moderately well to excessively drained, which suits most garden plants.

For lawns and yards

On 88% 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 93% of the acres in mapped Shedd soils very limited, 0% somewhat limited and 0% not limited (7% not rated, such as urban land, pits or water).

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 Shedd soil is found

Mapped acres

Shedd is mapped in California.

Counties with the most mapped Shedd soil
County	Acres	Share of county land
Monterey County, CA	93,980	4.4%
Santa Barbara County, CA	40,809	3.7%
San Benito County, CA	13,278	1.5%
Alameda County, CA	3,046	0.6%
Glenn County, CA	2,945	0.3%
San Luis Obispo County, CA	65	0.0%
Kern County, CA	46	0.0%

Septic absorption fields

NRCS rating, share of Shedd acres

Not limited 0%

Somewhat limited 0%

Very limited 93%

Not rated 7%

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

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Septic tank absorption field rating across mapped Shedd acres.
Category	Share of acres
Not limited	0.0%
Somewhat limited	0.0%
Very limited	93.1%
Not rated	6.9%

Drainage, water table and flooding

Share of Shedd 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 20–60% (median 40%).
Topsoil organic matter: Median 3%.

Drainage class

Excessively drained 0%

Somewhat excessively drained <1%

Well drained 93%

Moderately well drained 0%

Somewhat poorly drained 0%

Poorly drained 0%

Very poorly drained 0%

Not rated 7%

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

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Drainage class across mapped Shedd acres.
Category	Share of acres
Excessively drained	0.0%
Somewhat excessively drained	0.6%
Well drained	92.5%
Moderately well drained	0.0%
Somewhat poorly drained	0.0%
Poorly drained	0.0%
Very poorly drained	0.0%
Not rated	6.8%

Hydrologic soil group

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

B: moderate infiltration 5%

C: slow infiltration 85%

D: very slow infiltration (clayey, shallow or wet) 3%

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%

Not rated 7%

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

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Hydrologic soil group across mapped Shedd acres.
Category	Share of acres
A: fast infiltration (mostly sandy or gravelly)	0.0%
B: moderate infiltration	4.9%
C: slow infiltration	85.3%
D: very slow infiltration (clayey, shallow or wet)	2.9%
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%
Not rated	6.9%

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 Shedd (component kind "Series") in SSURGO: 154,500 acres.
Method: Shares are by mapped acres of Shedd components. The profile comes from the single largest Shedd component. Full methodology.

Independent reference site. No government affiliation or endorsement.

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