Soil pH in Washington, IN: Lime or Sulfur?

Typical topsoil pH in Washington, IN

Typical topsoil in Washington, IN is pH 5.82, just outside the 6-7 range for vegetable garden. Test first; it may need nothing.

What Washington needs, by plant

• Already in range: potatoes, strawberries, azaleas and rhododendrons.
• Just outside, test first: lawn (cool-season grass) (off by 0.2), vegetable garden (off by 0.2), roses (off by 0.2), pink hydrangeas (off by 0.2).
• Lime: tomatoes 4.9 lb/100 sq ft.
• Sulfur: blueberries 1.8 lb/100 sq ft; blue hydrangeas 1.4 lb/100 sq ft.

What to do next

If your test lands near 5.82, you can skip lime and sulfur for lawn (cool-season grass), vegetable garden, potatoes, strawberries, roses, azaleas and rhododendrons, pink hydrangeas.

How mixed the soil is

Of the 327,858 surveyed acres in Washington, IN, 82% are moderately acidic (5.5-6.5), 15% are strongly acidic (below 5.5), 3% are near neutral (6.5-7.3). Mapped soils run from pH 4.2 to 7, a spread of 2.8 units across 133 soil components. 82% 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 17.3% clay and 2.17% organic matter, which this site treats as loam. Moving it one pH unit takes about 7 lb of lime or 2.3 lb of sulfur per 100 sq ft. None of the mapped components carry free carbonate.

Washington against the rest of Indiana

pH 5.82 is 0.53 below the Indiana median of 6.35. 10 of 92 Indiana counties have more acidic topsoil. Nationally it is more acidic than the US county median of 6.05.

Closest in pH within the state: Floyd (5.7), Clark (5.76), Scott (5.79), Orange (5.8), Lawrence (5.84), Jackson (5.86), Greene (5.87), Owen (5.87).

The range in Indiana runs from Brown at 4.97 to Hamilton at 6.74; Washington sits 48% of the way up.