Soil series profile

Lofgren soil series

Lofgren is a poorly drained soil with a clay surface, mapped on 27,335 acres in 1 county in CA. Hydrologic group D.

#8804 by mapped area very-fine Xeric Epiaquerts (Vertisols)

Drainage class
Poorly drained
94% of mapped acres
Hydrologic group
D
94% of mapped acres
Typical topsoil pH
5.1
strongly acidic · range 5.1–6.0
Mapped area
27k
acres in 1 county, 1 state

Typical Lofgren profile

Texture and pH by depth

Typical Lofgren soil profile by depth 0 in 20 in 40 in 60 in 80 in 0–5 in · Ap · pH 5.1 · 66% clay Clay 5–12 in · Bssg1 · pH 6.7 · 65% clay Clay 12–29 in · Bssg2 · pH 7.5 · 66% clay Clay 29–38 in · Bkssg · pH 8.1 · 65% clay Clay 38–44 in · Bkg · pH 8.1 · 61% clay Clay 44–47 in · 2Bkq · pH 8.5 · 29% clay Clay loam 47–62 in · 2Bkqm1 · pH 8.7 · 16% clay Cemented material 62–82 in · 2Bkqm2 · pH 8.4 · 17% clay Cemented material
Depth to scale. More strongly shaded layers hold more clay. Horizon names are the soil survey's (A = topsoil, B = subsoil, C = parent material).
Show as a table
Typical Lofgren horizons (representative values)
Depth Texture pH Clay Sand Organic matter
0–5 in (Ap) Clay 5.1 66% 7% 2.64%
5–12 in (Bssg1) Clay 6.7 65% 9% 1.22%
12–29 in (Bssg2) Clay 7.5 66% 8% 0.71%
29–38 in (Bkssg) Clay 8.1 65% 10% 0.55%
38–44 in (Bkg) Clay 8.1 61% 13% 0.62%
44–47 in (2Bkq) Clay loam 8.5 29% 34% 0.38%
47–62 in (2Bkqm1) Cemented material 8.7 16% 50% 0.21%
62–82 in (2Bkqm2) Cemented material 8.4 17% 50% 0.09%

Representative values from the most extensive Lofgren map unit (Lofgren-Blavo , 0 to 1 percent slopes, survey area CA612). Other map units of this series vary within the series range.

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

What this means

What Lofgren soil means for gardens, lawns and septic systems

For gardens

Typical topsoil in Lofgren soils is strongly acidic: pH 5.1 (most land between 5.1 and 6.0). 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.

Clayey topsoil covers 94% of mapped Lofgren acres. Clay holds water and nutrients but drains slowly and compacts if worked wet: add compost, avoid tilling soggy soil and consider raised beds. The most common surface texture is clay (94% of mapped Lofgren acres).

94% of mapped Lofgren acres is somewhat poorly to very poorly drained, so soil stays soggy for long spells after rain and in wet seasons. Raised beds, plants that tolerate wet feet, and not working the soil while wet all help.

For lawns and yards

On 94% 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 94% of the acres in mapped Lofgren soils very limited, 0% somewhat limited and 0% not limited (6% 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.

Flooding is mapped on 94% of the acres (30% occasional, 0% 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.

Where Lofgren soil is found

Mapped acres

Lofgren is mapped in California.

Counties with the most mapped Lofgren soil
County Acres Share of county land
Butte County, CA 27,335 2.0%

Septic absorption fields

NRCS rating, share of Lofgren acres

Not limited 0%
Somewhat limited 0%
Very limited 94%
Not rated 6%
Septic tank absorption field rating across mapped Lofgren acres. Scale 0 to 100% of mapped land.
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Septic tank absorption field rating across mapped Lofgren acres.
CategoryShare of acres
Not limited0.0%
Somewhat limited0.0%
Very limited94.4%
Not rated5.6%

Drainage, water table and flooding

Share of Lofgren acres

Depth to seasonal high water table
About 1.7 feet (20 in) (median where reported).
Flooding
Mapped as flooding on 94% of acres (30% occasional, 0% frequent).
Slope
Typically 0–0% (median 0%).
Topsoil organic matter
Median 2.6%.

Drainage class

Excessively drained 0%
Somewhat excessively drained 0%
Well drained 0%
Moderately well drained 0%
Somewhat poorly drained 0%
Poorly drained 94%
Very poorly drained 0%
Not rated 6%
Drainage class across mapped Lofgren acres. Scale 0 to 100% of mapped land.
Show as a table
Drainage class across mapped Lofgren acres.
CategoryShare of acres
Excessively drained0.0%
Somewhat excessively drained0.0%
Well drained0.0%
Moderately well drained0.0%
Somewhat poorly drained0.0%
Poorly drained94.4%
Very poorly drained0.0%
Not rated5.6%

Hydrologic soil group

A: fast infiltration (mostly sandy or gravelly) 0%
B: moderate infiltration 0%
C: slow infiltration 0%
D: very slow infiltration (clayey, shallow or wet) 94%
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 6%
Hydrologic soil group across mapped Lofgren acres. Scale 0 to 100% of mapped land.
Show as a table
Hydrologic soil group across mapped Lofgren acres.
CategoryShare of acres
A: fast infiltration (mostly sandy or gravelly)0.0%
B: moderate infiltration0.0%
C: slow infiltration0.0%
D: very slow infiltration (clayey, shallow or wet)94.4%
A/D: D as is, A if drained0.0%
B/D: D as is, B if drained0.0%
C/D: D as is, C if drained0.0%
Not rated5.6%

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 Lofgren (component kind "Series") in SSURGO: 27,335 acres.
Method
Shares are by mapped acres of Lofgren components. The profile comes from the single largest Lofgren component. Full methodology.

Independent reference site. No government affiliation or endorsement.

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