Soil series profile

Harstine soil series

Harstine is a moderately well drained soil with a gravelly ashy sandy loam surface, mapped on 78,557 acres in 3 counties in WA. Hydrologic group C.

#4245 by mapped area coarse-loamy Vitrandic Dystroxerepts (Inceptisols)

Drainage class: Moderately well drained
Hydrologic group: C
Typical topsoil pH: 5.0
Mapped area: 79k

Typical Harstine 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 Harstine horizons (representative values)
Depth	Texture	pH	Clay	Sand	Organic matter
0–0 in (Oi)	Slightly decomposed plant material	4.5	10%	70%	75%
0–1 in (Oe)	Moderately decomposed plant material	4.5	10%	70%	75%
1–6 in (Bw1)	Gravelly ashy sandy loam	5.0	10%	70%	7.5%
6–14 in (Bw2)	Gravelly ashy sandy loam	5.4	10%	70%	2%
14–22 in (Bw3)	Gravelly ashy sandy loam	5.4	8%	70%	2%
22–32 in (Bw4)	Gravelly ashy sandy loam	5.6	8%	70%	0.2%
32–38 in (2Cd1)	Gravelly loamy sand	5.8	5%	80%	0.05%
38–61 in (2Cd2)	Gravelly loamy sand	5.8	5%	80%	0.05%

Representative values from the most extensive Harstine map unit (Harstine gravelly ashy sandy loam, 6 to 15 percent slopes, survey area WA653). 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 Harstine soil means for gardens, lawns and septic systems

For gardens

Typical topsoil in Harstine soils is very strongly acidic: pH 5.0. 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.

Sandy topsoil covers 100% of mapped Harstine acres. It drains fast and warms early in spring, but dries out and loses nutrients quickly: mulch, compost and steady watering help. The most common surface texture is gravelly ashy sandy loam (100% of mapped Harstine acres).

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

For lawns and yards

On 98% 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 80% of the acres in mapped Harstine soils very limited, 20% 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 Harstine soil is found

Mapped acres

Harstine is mapped in Washington.

Counties with the most mapped Harstine soil
County	Acres	Share of county land
Pierce County, WA	42,740	3.9%
Kitsap County, WA	29,501	11.7%
Mason County, WA	6,317	1.1%

Septic absorption fields

NRCS rating, share of Harstine acres

Not limited 0%

Somewhat limited 20%

Very limited 80%

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

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Septic tank absorption field rating across mapped Harstine acres.
Category	Share of acres
Not limited	0.0%
Somewhat limited	20.2%
Very limited	79.8%

Drainage, water table and flooding

Share of Harstine acres

Depth to seasonal high water table: About 2.5 feet (30 in) (median where reported).
Flooding: Not mapped as flooding on most acres.
Slope: Typically 3–25% (median 10%).
Topsoil organic matter: Median 7.5%.

Drainage class

Excessively drained 0%

Somewhat excessively drained 0%

Well drained 0%

Moderately well drained 100%

Somewhat poorly drained 0%

Poorly drained 0%

Very poorly drained 0%

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

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Drainage class across mapped Harstine acres.
Category	Share of acres
Excessively drained	0.0%
Somewhat excessively drained	0.0%
Well drained	0.0%
Moderately well drained	100.0%
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 98%

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%

Not rated 2%

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

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Hydrologic soil group across mapped Harstine acres.
Category	Share of acres
A: fast infiltration (mostly sandy or gravelly)	0.0%
B: moderate infiltration	0.0%
C: slow infiltration	97.7%
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%
Not rated	2.3%

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: All map unit components named Harstine (component kind "Series") in SSURGO: 78,557 acres.
Method: Shares are by mapped acres of Harstine components. The profile comes from the single largest Harstine component. Full methodology.

Independent reference site. No government affiliation or endorsement.

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