Soil pH in Rock, WI: Lime or Sulfur?

Typical topsoil pH in Rock, WI

Typical topsoil in Rock, WI is pH 6.57, already right for vegetable garden (6-7). Test before adding anything.

What Rock needs, by plant

• Already in range: lawn (cool-season grass), vegetable garden, tomatoes, roses.
• Just outside, test first: strawberries (off by 0.1), pink hydrangeas (off by 0.1).
• Sulfur: potatoes 2.5 lb/100 sq ft over 2 applications; blueberries 3.7 lb/100 sq ft over 2 applications; azaleas and rhododendrons 3 lb/100 sq ft over 2 applications; blue hydrangeas 3 lb/100 sq ft over 2 applications.

What to do next

If your test lands near 6.57, you can skip lime and sulfur for lawn (cool-season grass), vegetable garden, tomatoes, strawberries, roses, pink hydrangeas.

How mixed the soil is

Of the 429,939 surveyed acres in Rock, WI, 76% are near neutral (6.5-7.3), 22% are moderately acidic (5.5-6.5), 2% are alkaline (above 7.3). Mapped soils run from pH 5.5 to 7.9, a spread of 2.4 units across 190 soil components. 76% 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 19.2% clay and 3.18% 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. 7% of mapped components carry free carbonate (lime already in the ground).

Rock against the rest of Wisconsin

pH 6.57 is 0.49 above the Wisconsin median of 6.08. 54 of 72 Wisconsin counties have more acidic topsoil. Nationally it is more alkaline than the US county median of 6.05.

Closest in pH within the state: Lafayette (6.5), Green (6.53), Dane (6.54), Columbia (6.55), Walworth (6.63), Green Lake (6.69), Milwaukee (6.69), Outagamie (6.69).

The range in Wisconsin runs from Iron at 5.16 to Washington at 6.88; Rock sits 82% of the way up.