Soil pH in Martin, FL: Lime or Sulfur?

Typical topsoil pH in Martin, FL

Typical topsoil in Martin, FL is pH 5.7, too acidic for vegetable garden. Expect roughly 2.4 lb of lime per 100 sq ft, but only after a soil test confirms it.

What Martin needs, by plant

• Already in range: potatoes, strawberries, azaleas and rhododendrons.
• Just outside, test first: blueberries (off by 0.2), blue hydrangeas (off by 0.2).
• Lime: lawn (cool-season grass) 2.4 lb/100 sq ft; vegetable garden 2.4 lb/100 sq ft; tomatoes 2.4 lb/100 sq ft; roses 2.4 lb/100 sq ft; pink hydrangeas 1.5 lb/100 sq ft.

What to do next

If your test confirms pH near 5.7, spread about 24 lb of ground limestone per 1,000 sq ft of vegetable bed, ideally in fall.

How mixed the soil is

Of the 335,924 surveyed acres in Martin, FL, 54% are moderately acidic (5.5-6.5), 37% are strongly acidic (below 5.5), 6% are near neutral (6.5-7.3), 3% are alkaline (above 7.3). Mapped soils run from pH 4.5 to 8.2, a spread of 3.7 units across 217 soil components. No single class covers 60% of the county, so two gardens a few miles apart here can need opposite treatments. Test your own bed.

Clay, organic matter and rates

Topsoil here averages 2.2% clay and 2.33% 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. 1% of mapped components carry free carbonate (lime already in the ground).

Martin against the rest of Florida

pH 5.7 is 0.45 above the Florida median of 5.25. 54 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: Seminole (5.59), Charlotte (5.6), Lee (5.63), Dixie (5.66), Levy (5.71), Collier (5.77), Indian River (5.78), Palm Beach (5.8).

The range in Florida runs from Franklin at 4.5 to Monroe at 7.81; Martin sits 36% of the way up.