Soil pH in Pointe Coupee, LA: Lime or Sulfur?

Typical topsoil pH in Pointe Coupee, LA

Typical topsoil in Pointe Coupee, LA is pH 6.84, already right for vegetable garden (6-7). Test before adding anything.

What Pointe Coupee needs, by plant

• Already in range: lawn (cool-season grass), vegetable garden, roses.
• Just outside, test first: tomatoes (off by 0).
• Sulfur: potatoes 4.4 lb/100 sq ft over 3 applications; strawberries 2.7 lb/100 sq ft over 2 applications; blueberries 6.1 lb/100 sq ft over 4 applications; azaleas and rhododendrons 5.4 lb/100 sq ft over 3 applications; blue hydrangeas 5.4 lb/100 sq ft over 3 applications; pink hydrangeas 2 lb/100 sq ft.

What to do next

If your test lands near 6.84, you can skip lime and sulfur for lawn (cool-season grass), vegetable garden, tomatoes, roses.

How mixed the soil is

Of the 265,847 surveyed acres in Pointe Coupee, LA, 87% are near neutral (6.5-7.3), 8% are strongly acidic (below 5.5), 5% are moderately acidic (5.5-6.5). Mapped soils run from pH 5 to 7.9, a spread of 2.9 units across 39 soil components. 87% 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 30.1% clay and 2.07% 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).

Pointe Coupee against the rest of Louisiana

pH 6.84 is 1.3 above the Louisiana median of 5.54. 61 of 64 Louisiana counties have more acidic topsoil. Nationally it is more alkaline than the US county median of 6.05.

Closest in pH within the state: Orleans (6.61), Plaquemines (6.71), St. James (6.76), St. John the Baptist (6.78), West Baton Rouge (6.9), St. Bernard (7).

The range in Louisiana runs from Allen at 4.88 to St. Bernard at 7; Pointe Coupee sits 92% of the way up.