Soil pH in Clark, KY: Lime or Sulfur?

Typical topsoil pH in Clark, KY

Typical topsoil in Clark, KY is pH 6.3, already right for vegetable garden (6-7). Test before adding anything.

What Clark needs, by plant

• Already in range: lawn (cool-season grass), vegetable garden, tomatoes, strawberries, roses, pink hydrangeas.
• Sulfur: potatoes 1.8 lb/100 sq ft; blueberries 3 lb/100 sq ft over 2 applications; azaleas and rhododendrons 2.3 lb/100 sq ft over 2 applications; blue hydrangeas 2.3 lb/100 sq ft over 2 applications.

What to do next

If your test lands near 6.3, 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 143,365 surveyed acres in Clark, KY, 41% are moderately acidic (5.5-6.5), 39% are near neutral (6.5-7.3), 12% are strongly acidic (below 5.5), 9% are alkaline (above 7.3). Mapped soils run from pH 4.6 to 7.9, a spread of 3.3 units across 236 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 24.6% clay and 2.76% 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. 8% of mapped components carry free carbonate (lime already in the ground).

Clark against the rest of Kentucky

pH 6.3 is 0.51 above the Kentucky median of 5.79. 105 of 120 Kentucky counties have more acidic topsoil. Nationally it is more alkaline than the US county median of 6.05.

Closest in pH within the state: Mason (6.25), Garrard (6.26), Scott (6.27), Washington (6.28), Spencer (6.33), Mercer (6.34), Nicholas (6.34), Bourbon (6.37).

The range in Kentucky runs from Greenup at 5.09 to Carroll at 6.63; Clark sits 79% of the way up.