Soil pH in Washington, FL: Lime or Sulfur?

Typical topsoil pH in Washington, FL

Typical topsoil in Washington, FL is pH 4.98, too acidic for vegetable garden. Expect roughly 4.5 lb of lime per 100 sq ft, but only after a soil test confirms it.

What Washington needs, by plant

• Already in range: blueberries, azaleas and rhododendrons.
• Just outside, test first: potatoes (off by 0), blue hydrangeas (off by 0).
• Lime: lawn (cool-season grass) 4.5 lb/100 sq ft; vegetable garden 4.5 lb/100 sq ft; tomatoes 4.5 lb/100 sq ft; strawberries 3 lb/100 sq ft; roses 4.5 lb/100 sq ft; pink hydrangeas 3.9 lb/100 sq ft.

What to do next

If your test confirms pH near 4.98, spread about 45 lb of ground limestone per 1,000 sq ft of vegetable bed, ideally in fall.

How mixed the soil is

Of the 380,668 surveyed acres in Washington, FL, 96% are strongly acidic (below 5.5), 5% are moderately acidic (5.5-6.5). Mapped soils run from pH 4.3 to 6.6, a spread of 2.3 units across 212 soil components. 96% 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 5.3% clay and 1.64% 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.

Washington against the rest of Florida

pH 4.98 is 0.27 below the Florida median of 5.25. 10 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: Taylor (4.9), Liberty (4.91), Duval (4.95), Calhoun (4.98), Gulf (4.99), Jefferson (5), Lafayette (5), Bay (5.01).

The range in Florida runs from Franklin at 4.5 to Monroe at 7.81; Washington sits 15% of the way up.