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Johnston County Soil Data

Johnston County, North Carolina

USDA SSURGO / PHZM

Avg pH

5.2

Texture

Sandy Loam

Drainage

N/A

Organic Matter

1.7%

Hydrologic Group

N/A

Data Story

About Soil in Johnston County, North Carolina

Typical Coastal Plain Acidity

The average pH here is 5.21, making it slightly less acidic than the state average of 5.14. It remains notably more acidic than the national median of 6.5, which usually requires lime for vegetable gardening.

High Sand for Rapid Drainage

With a high sand content of 65.3%, this soil is built for rapid water movement and easy workability. Silt accounts for 23.1%, while clay is low at 11.6%, meaning nutrients may leach through the profile faster than in heavier soils.

Lean Soil Requires Enrichment

Organic matter levels are low at 1.73%, falling far short of the North Carolina average of 5.12%. The available water capacity of 0.118 in/in is also below the state benchmark, suggesting a need for frequent irrigation during summer.

Efficient Water Movement

There is currently no specific data on drainage classes or hydrologic groups for this county. Given the 65.3% sand percentage, most areas likely experience rapid drainage that prevents root rot during wet seasons.

Abundant Sun in Zone 8a

Zone 8a conditions allow for an extensive variety of crops, from cotton and tobacco to backyard blueberries. Adding heavy layers of compost will help improve the low water retention of this sandy landscape.

Soil Composition

Sandy Loam
Sand: 65.3%
Silt: 23.1%
Clay: 11.6%
Sandy Loam

Soil pH

5.2pH
5.21124715937646
Strongly AcidicSlightly AcidicNeutralSlightly AlkalineStrongly Alkaline
Ideal lawn range: 6.0 - 7.0

Soil Series

Detailed soil series data not yet available for this county.

Hydrologic Group

Hydrologic group data not available.

Drainage Class

Drainage class data not available.

Soil Profile

Dominant texture: Sandy Loam

O HorizonOrganic layer
0-2"
A HorizonTopsoil
2-10"
B HorizonSubsoil
10-30"
C HorizonParent material
30-60"
R HorizonBedrock
60"+

Typical soil profile. Actual depths vary by location.

Acidic Soil Detected

Your county's average pH is 5.2. These products help balance soil pH for healthier grass.

Browse Soil Amendments

Frequently Asked Questions

What type of soil does Johnston County have?

Johnston County's soil is classified as Sandy Loam. This indicates the relative proportions of sand, silt, and clay — 65% sand, 23% silt, and 12% clay. Loamy soils hold moisture well and support a wide range of plants.

Is Johnston County's soil acidic or alkaline?

Johnston County's soil has a low pH of 5.2, which is strongly acidic. Acidic soils benefit from lime applications to raise pH and improve nutrient availability.

What is the drainage class for Johnston County?

Drainage class data is not currently available for Johnston County.

What crops or plants grow well in Johnston County's soil?

Based on Johnston County's Sandy Loam texture, pH of 5.2, and drainage class, the soil is well suited for acid-loving plants like blueberries and azaleas, row crops and vegetable gardens.

What USDA soil order is found in Johnston County?

The dominant USDA soil order for Johnston County is not currently available in our dataset.

Soil & Planting Advisory: Johnston County

Soil Verdict

Johnston County is in USDA hardiness zone 8a, a warm climate zone. where winter lows can reach 10°F. Mild winters mean soil rarely freezes deeply, allowing year-round microbial activity and faster organic matter breakdown.

Planting Guidance

Warm-season crops, citrus relatives, and heat-loving ornamentals do well. Cool-season vegetables should be planted in fall and winter. Always match plant selections to the specific microclimate of your property — low spots, slopes, and wind exposure can shift effective hardiness by half a zone.

Soil Implications

Warm soils accelerate organic matter breakdown, so compost and mulch need replenishing more frequently than in cooler zones. Sandy soils common in warm zones drain quickly; water-retentive amendments like compost or peat help hold moisture.

Regional Context

Johnston County closely matches the North Carolina average hardiness conditions.

Other Counties in North Carolina

By Evan Brooks, Data EditorUpdated Reviewed by Evan Brooks, Data Editor

Soil data sourced from USDA SSURGO via Soil Data Access. Data is informational only and should not be used as a substitute for on-site soil testing. Contact your local NRCS office for site-specific soil information.