Soil pH in Polk, TX: Lime or Sulfur?

Typical topsoil pH in Polk, TX

Typical topsoil in Polk, TX is pH 5.23, too acidic for vegetable garden. Expect roughly 9.1 lb of lime per 100 sq ft, but only after a soil test confirms it.

What Polk needs, by plant

• Already in range: potatoes, blueberries, azaleas and rhododendrons, blue hydrangeas.
• Lime: lawn (cool-season grass) 9.1 lb/100 sq ft over 2 applications; vegetable garden 9.1 lb/100 sq ft over 2 applications; tomatoes 9.1 lb/100 sq ft over 2 applications; strawberries 5.6 lb/100 sq ft over 2 applications; roses 9.1 lb/100 sq ft over 2 applications; pink hydrangeas 7 lb/100 sq ft over 2 applications.

What to do next

If your test confirms pH near 5.23, spread about 91 lb of ground limestone per 1,000 sq ft of vegetable bed in 2 doses, ideally in fall.

How mixed the soil is

Of the 597,861 surveyed acres in Polk, TX, 63% are strongly acidic (below 5.5), 33% are moderately acidic (5.5-6.5), 4% are near neutral (6.5-7.3). Mapped soils run from pH 3.4 to 8.2, a spread of 4.8 units across 95 soil components. 63% of the land falls in one class, so the county figure is a fair first guess for most yards here.

Clay, organic matter and rates

Topsoil here averages 13.7% clay and 1.14% organic matter, which this site treats as loam. Moving it one pH unit takes about 7 lb of lime or 2.3 lb of sulfur per 100 sq ft. 3% of mapped components carry free carbonate (lime already in the ground).

Polk against the rest of Texas

pH 5.23 is 2.2 below the Texas median of 7.43. 6 of 254 Texas counties have more acidic topsoil. Nationally it is more acidic than the US county median of 6.05.

Closest in pH within the state: Liberty (5.13), Newton (5.17), San Jacinto (5.21), Tyler (5.21), Montgomery (5.27), Orange (5.31), Marion (5.36), Harrison (5.37).

The range in Texas runs from Hardin at 4.64 to Upton at 8.19; Polk sits 17% of the way up.