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Willacy County Soil Data

Willacy County, Texas

USDA SSURGO / PHZM

Avg pH

7.6

Texture

Sandy Loam

Drainage

N/A

Organic Matter

1.2%

Hydrologic Group

A

Data Story

About Soil in Willacy County, Texas

Sandy Coastal Soils of South Texas

Willacy County features highly alkaline soils with an average pH of 7.57, well above the national median of 6.5. While specific taxonomic orders are not documented here, the high alkalinity is characteristic of the Rio Grande Valley. This environment requires plants that can tolerate more basic conditions.

Dominated by Deep Sands

Sand makes up a staggering 65.0% of the soil profile, with only 15.6% silt and 19.4% clay. This high sand content means the soil is exceptionally easy to work but struggles to hold onto nutrients. It is a stark contrast to the heavier clay soils found in central parts of the state.

Low Retention in a Warm Climate

Organic matter is low at 1.23%, falling below the state average of 1.66%. The available water capacity is also quite low at 0.099 in/in, compared to the state average of 0.133 in/in. This means irrigation is essential for any consistent growing success in the county.

Fast Infiltration and High Permeability

The soil belongs to Hydrologic Group A, which indicates high infiltration rates and low runoff potential. While specific drainage classes aren't listed, Group A soils are typically the most permeable, letting water move through quickly. This is ideal for avoiding flooding but challenging for moisture-loving plants.

Subtropical Gardening in Zone 10a

Willacy is in Zone 10a, allowing for a year-round growing season that includes citrus and tropical fruits. The soil's low water capacity and high pH mean you should focus on drought-tolerant, alkaline-loving species. Adding organic mulch will be your best strategy to keep your sandy garden productive.

Soil Composition

Sandy Loam
Sand: 65.0%
Silt: 15.6%
Clay: 19.4%
Sandy Loam

Soil pH

7.6pH
7.57448787440579
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

Group A — Low Runoff

Sandy, well-drained soils with high infiltration rates. Water moves quickly through the soil profile. Lowest runoff potential when thoroughly wetted.

Runoff potential:Low

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.

Alkaline Soil Detected

Your county's average pH is 7.6. These products help acidify soil for better nutrient uptake.

Browse Soil Amendments

Frequently Asked Questions

What type of soil does Willacy County have?

Willacy County's soil is classified as Sandy Loam. This indicates the relative proportions of sand, silt, and clay — 65% sand, 16% silt, and 19% clay. Loamy soils hold moisture well and support a wide range of plants.

Is Willacy County's soil acidic or alkaline?

Willacy County's soil has a pH of 7.6, which is mildly to moderately alkaline. Sulfur amendments can lower pH if needed.

What is the drainage class for Willacy County?

Drainage class data is not currently available for Willacy County.

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

Based on Willacy County's Sandy Loam texture, pH of 7.6, and drainage class, the soil is well suited for drought-tolerant crops and native grasses, row crops and vegetable gardens.

What USDA soil order is found in Willacy County?

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

Soil & Planting Advisory: Willacy County

Soil Verdict

Willacy County is in USDA hardiness zone 10a, a very warm climate zone. where winter lows can reach 30°F. Warm winters keep soil biology active nearly year-round, accelerating decomposition but increasing pest and disease pressure in topsoil.

Planting Guidance

Tropical and subtropical plants are viable. Year-round gardening is possible, though summer heat may limit some cool-season crops. Frost is rare; tender plants can overwinter with minimal protection. 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

Rapid organic matter turnover means soils can become nutrient-poor quickly; test annually and fertilize based on results. High soil temperatures favor certain soilborne pathogens; practice crop rotation and avoid overwatering.

Regional Context

Willacy County is significantly warmer than the Texas average, shifting effective hardiness by roughly 1.8 zones.

Other Counties in Texas

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.