Soil pH in Clay, FL: Lime or Sulfur?

Typical topsoil pH in Clay, FL

Typical topsoil in Clay, FL is pH 4.79, too acidic for vegetable garden. Expect roughly 5.1 lb of lime per 100 sq ft, but only after a soil test confirms it.

What Clay needs, by plant

• Already in range: blueberries, azaleas and rhododendrons.
• Just outside, test first: potatoes (off by 0.2), blue hydrangeas (off by 0.2).
• Lime: lawn (cool-season grass) 5.1 lb/100 sq ft over 2 applications; vegetable garden 5.1 lb/100 sq ft over 2 applications; tomatoes 5.1 lb/100 sq ft over 2 applications; strawberries 3.6 lb/100 sq ft; roses 5.1 lb/100 sq ft over 2 applications; pink hydrangeas 4.5 lb/100 sq ft.

What to do next

If your test confirms pH near 4.79, spread about 51 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 375,911 surveyed acres in Clay, FL, 94% are strongly acidic (below 5.5), 6% are moderately acidic (5.5-6.5). Mapped soils run from pH 4 to 6.2, a spread of 2.2 units across 322 soil components. 94% 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 2.6% clay and 2.38% organic matter, which this site treats as sandy. Moving it one pH unit takes about 3 lb of lime or 1.2 lb of sulfur per 100 sq ft. None of the mapped components carry free carbonate.

Clay against the rest of Florida

pH 4.79 is 0.46 below the Florida median of 5.25. 4 of 67 Florida counties have more acidic topsoil. Nationally it is more acidic than the US county median of 6.05.

Closest in pH within the state: Franklin (4.5), Baker (4.65), Columbia (4.72), Union (4.78), Madison (4.86), Bradford (4.87), Taylor (4.9), Liberty (4.91).

The range in Florida runs from Franklin at 4.5 to Monroe at 7.81; Clay sits 9% of the way up.