LOCATION DAROW OR
Established Series
Rev. DKS/RHB/TDT
12/2025
DAROW SERIES
The Darow series consists of moderately deep, moderately well drained soils that formed in residuum and colluvium weathered from siltstone or shale. Darow soils are on hillslopes and have slopes of 1 to 35 percent. The mean annual precipitation is about 24 inches (610 mm) and the mean annual air temperature is about 53 degrees F (12 degrees C).
TAXONOMIC CLASS: Fine, smectitic, mesic Vertic Argixerolls
TYPICAL PEDON: Darow silty clay loam, forested. (Colors are for moist soil unless otherwise noted.)
A1--0 to 5 inches (0 to 13 cm); dark brown (10YR 3/3) silty clay loam, brown (10YR 5/3) dry; strong medium granular structure; hard, friable, slightly sticky and plastic; many fine roots; many irregular pores; neutral (pH 6.8); abrupt smooth boundary. (4 to 7 inches (10 to 18 cm) thick)
A2--5 to 12 inches (13 to 30 cm); dark brown (10YR 3/3) silty clay loam, brown (10YR 5/3) dry; moderate fine subangular blocky structure; hard, friable, sticky and plastic; common fine and few medium roots; many very fine tubular pores; neutral (pH 6.6); clear smooth boundary. (6 to 9 inches (15 to 23 cm) thick)
BA--12 to 21 inches (30 to 53 cm); brown (10YR 4/3) silty clay, yellowish brown (10YR 5/4) dry; weak coarse subangular blocky structure; very hard, firm, very sticky and plastic; few fine and common medium roots; common very fine tubular pores; slightly acid (pH 6.4); clear smooth boundary. (3 to 10 inches (8 to 25 cm) thick)
Bt--21 to 32 inches (53 to 81 cm); dark yellowish brown (10YR 4/4) silty clay, yellowish brown (10YR 5/4) dry; weak coarse prismatic structure; very hard, very firm, very sticky and very plastic; common fine roots; common very fine tubular pores; few moderately thick clay films on peds and in pores; slightly acid (pH 6.4); clear wavy boundary. (7 to 15 inches (18 to 38 cm) thick)
Crt--32 inches (81 cm); weathered siltstone bedrock with thick brown (7.5YR 4/4) clay films in fractures.
TYPE LOCATION: Jackson County, Oregon; 4 miles south of Medford, about 850 feet south and 1,750 feet west from the NE corner of sec. 13, T. 38 S., R. 2 W., W.M.
RANGE IN CHARACTERISTICS: The mean annual soil temperature ranges from 54 to 56 degrees F (12 to 13 degrees C). The soils are usually moist but, in most years, they are dry between 4 and 12 inches (10 to 30 cm) for 80 to 110 consecutive days during the summer. The soils crack to 20 inches (50 cm) or more in the summer months in more than 7 out of 10 years. Depth to a paralithic contact is 20 to 40 inches (50 to 100 cm). It has 0 to 5 percent gravel.
The A horizon has hue of 10YR or 7.5YR, value of 3 moist, 5 dry, and chroma of 2 or 3 moist and 3 or 4 dry.
The Bt horizon has hue of 10YR, 7.5YR, or 2.5Y, value of 4 or 5 moist, 5 or 6 dry, and chroma of 3 or 4 moist and dry. It is a silty clay or clay with 45 to 60 percent clay. Soft gravel fragments range from 0 to 15 percent.
COMPETING SERIES: These are the
Adaboi,
Ayette,
Forsgren,
Gimmi,
Hann,
Karney,
Kuck,
Leepcreek, McDesh,
Montour,
Tub, and
Ukiah series. Adaboi, Forsgren, and Hann soils do not have bedrock within 60 inches (150 cm). Ayette soils have a paralithic contact between 100 and 150 cm and slickensides in the argillic horizon. Gimmi soils are well drained and average 15 to 35 percent gravel and cobbles in the argillic horizon. Karney soils are well drained, have a mean annual soil temperature of 49 to 53 degrees F (9 to 12 degrees C), and have a lithic contact below the paralithic contact. Kuck soils have a mean annual precipitation of 12 to 20 inches (305 to 510 mm), 5 to 30 percent rock fragments, and value of 2 or 3 dry in the A horizon and 4 or 5 dry in the Bt, chroma of 1 to 3 dry in the A horizon and 1 or 2 dry in the Bt. Leepcreek soils have a lithic contact between 100 and 150 cm. McDesh soils have a lithic contact between 50 and 100 cm. Montour soils have calcareous C horizons and do not have bedrock within 60 inches (150 cm). Tub soils contain secondary carbonates, do not have bedrock within 150 cm, and have a mean annual soil temperature of 47 to 50 degrees F (8 to 10 degrees C). Ukiah soils have a mean annual soil temperature of 47 to 51 degrees F (8 to 11 degrees C).
GEOGRAPHIC SETTING: Darow soils are on hillslopes at elevations of 1,200 to 3,000 feet (365 to 910 m). Slopes range from 1 to 35 percent. The soils formed in residuum and colluvium weathered from siltstone, shale or tuffaceous sandstone rocks. The mean annual precipitation is 18 to 30 inches (460 to 720 mm). The mean annual air temperature is 52 to 54 degrees F (12 to 13 degrees C). The frost-free period is 120 to 180 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Brader,
Carney,
Debenger,
Manita, and
Selmac soils. Carney soils have intersecting slickensides. Manita soils are well drained and have ochric epipedons. Selmac soils have an ochric epipedon and are fine-loamy over clayey in the control section. Brader soils are less than 20 inches (50 cm) to bedrock. Debenger soils are fine-loamy.
DRAINAGE AND PERMEABILITY: Moderately well drained; medium to rapid runoff; slow permeability.
USE AND VEGETATION: Used mainly for pasture, hay, pears, grazing and homesites. Native vegetation consists of Oregon white oak, poison oak, birchleaf mountain mahogany, ponderosa pine, Idaho fescue, Junegrass, and other grasses.
DISTRIBUTION AND EXTENT: Southwestern Oregon. The series is inextensive.
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Jackson County Area, Oregon, 1988.
REMARKS:
Particle Size Control Section for this pedon: 53 to 81 cm
Diagnostic horizons and features recognized in this pedon are:
Mollic Epipedon: 0 to 30 cm
Argillic Horizon: 53 to 81 cm
Paralithic Contact: 81 cm
Vertic Subgroup: cracks to a depth of 50 cm or more
Added metric depths and updated competing series 12/2025. -JBB
National Cooperative Soil Survey
U.S.A.