Soil series profile

Tolstoi soil series

Tolstoi is a moderately well drained soil with a silt loam surface, mapped on 676,522 acres in 4 counties in AK. Hydrologic group D.

#358 by mapped area loamy-skeletal Lithic Humicryods (Spodosols)

Drainage class: Moderately well drained
Hydrologic group: D
Typical topsoil pH: 5.3
Mapped area: 677k

Typical Tolstoi 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 Tolstoi horizons (representative values)
Depth	Texture	pH	Clay	Sand	Organic matter
0–4 in (Oe)	Moderately decomposed plant material	3.8	Not reported	Not reported	80%
4–6 in (E)	Silt loam	5.3	3%	27%	7%
6–10 in (Bhs)	Highly organic very fine sandy loam	5.3	3%	58%	12%
10–20 in (Bs)	Very gravelly fine sandy loam	5.3	5%	60%	4%
20–60 in (R)	Unweathered bedrock	Not reported	Not reported	Not reported	Not reported

Representative values from the most extensive Tolstoi map unit (Tolstoi and Kaikli soils, alpine, 76 to 120 percent slopes, survey area AK646). 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 Tolstoi soil means for gardens, lawns and septic systems

For gardens

Typical topsoil in Tolstoi soils is strongly acidic: pH 5.3 (most land between 4.5 and 5.3). 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 Tolstoi acres: generally the easiest soil to garden, holding moisture without staying waterlogged. The most common surface texture is silt loam (51% of mapped Tolstoi acres).

100% of mapped Tolstoi 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 Tolstoi 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 Tolstoi soil is found

Mapped acres

Tolstoi is mapped in Alaska.

Counties with the most mapped Tolstoi soil
County	Acres	Share of county land
Hoonah-Angoon Census Area, AK	238,474	5.8%
Ketchikan Gateway Borough, AK	215,385	6.0%
Wrangell-Petersburg Census Area, AK	118,219	2.2%
Haines Borough, AK	104,443	7.3%

Septic absorption fields

NRCS rating, share of Tolstoi acres

Not limited 0%

Somewhat limited 0%

Very limited 100%

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

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

Drainage, water table and flooding

Share of Tolstoi 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 21–88% (median 66%).
Topsoil organic matter: Median 7%.

Drainage class

Excessively drained 0%

Somewhat excessively drained 0%

Well drained 44%

Moderately well drained 56%

Somewhat poorly drained 0%

Poorly drained 0%

Very poorly drained 0%

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

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Drainage class across mapped Tolstoi acres.
Category	Share of acres
Excessively drained	0.0%
Somewhat excessively drained	0.0%
Well drained	43.8%
Moderately well drained	56.2%
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 0%

D: very slow infiltration (clayey, shallow or wet) 100%

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 Tolstoi acres. Scale 0 to 100% of mapped land.

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Hydrologic soil group across mapped Tolstoi acres.
Category	Share of acres
A: fast infiltration (mostly sandy or gravelly)	0.0%
B: moderate infiltration	0.0%
C: slow infiltration	0.0%
D: very slow infiltration (clayey, shallow or wet)	100.0%
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 Tolstoi (component kind "Series") in SSURGO: 676,522 acres.
Method: Shares are by mapped acres of Tolstoi components. The profile comes from the single largest Tolstoi component. Full methodology.

Independent reference site. No government affiliation or endorsement.

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