Soil pH in Catahoula, LA: Lime or Sulfur?

Typical topsoil pH in Catahoula, LA

Typical topsoil in Catahoula, LA is pH 5.52, too acidic for vegetable garden. Expect roughly 11.5 lb of lime per 100 sq ft, but only after a soil test confirms it.

What Catahoula needs, by plant

• Already in range: potatoes, strawberries, azaleas and rhododendrons.
• Just outside, test first: blueberries (off by 0), blue hydrangeas (off by 0).
• Lime: lawn (cool-season grass) 11.5 lb/100 sq ft over 3 applications; vegetable garden 11.5 lb/100 sq ft over 3 applications; tomatoes 11.5 lb/100 sq ft over 3 applications; roses 11.5 lb/100 sq ft over 3 applications; pink hydrangeas 8 lb/100 sq ft over 2 applications.

What to do next

If your test confirms pH near 5.52, spread about 115 lb of ground limestone per 1,000 sq ft of vegetable bed in 3 doses, ideally in fall.

How mixed the soil is

Of the 387,535 surveyed acres in Catahoula, LA, 65% are strongly acidic (below 5.5), 21% are moderately acidic (5.5-6.5), 13% are near neutral (6.5-7.3), 1% are alkaline (above 7.3). Mapped soils run from pH 4.3 to 8, a spread of 3.7 units across 91 soil components. 65% 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 37% clay and 2.04% organic matter, which this site treats as clay. Moving it one pH unit takes about 11.5 lb of lime or 3.4 lb of sulfur per 100 sq ft. 1% of mapped components carry free carbonate (lime already in the ground).

Catahoula against the rest of Louisiana

pH 5.52 is right at the Louisiana median of 5.54. 30 of 64 Louisiana counties have more acidic topsoil. Nationally it is more acidic than the US county median of 6.05.

Closest in pH within the state: Jefferson Davis (5.41), Richland (5.44), Acadia (5.45), Tangipahoa (5.48), Livingston (5.52), Lafayette (5.55), West Feliciana (5.6), Bossier (5.66).

The range in Louisiana runs from Allen at 4.88 to St. Bernard at 7; Catahoula sits 30% of the way up.