Soil pH in Franklin, KY: Lime or Sulfur?

Typical topsoil pH in Franklin, KY

Typical topsoil in Franklin, KY is pH 6.45, already right for vegetable garden (6-7). Test before adding anything.

What Franklin needs, by plant

• Already in range: lawn (cool-season grass), vegetable garden, tomatoes, strawberries, roses, pink hydrangeas.
• Beds or pots instead: potatoes, blueberries, azaleas and rhododendrons, blue hydrangeas.

What to do next

If your test lands near 6.45, 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 117,702 surveyed acres in Franklin, KY, 67% are near neutral (6.5-7.3), 26% are moderately acidic (5.5-6.5), 6% are alkaline (above 7.3), 2% are strongly acidic (below 5.5). Mapped soils run from pH 4.5 to 7.5, a spread of 3 units across 136 soil components. 67% 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 27.3% clay and 2.49% organic matter, which this site treats as clay. Moving it one pH unit takes about 11.5 lb of lime or 3.4 lb of sulfur per 100 sq ft. 38% of mapped components carry free carbonate (lime already in the ground), enough that sulfur gets neutralised before it does much.

Franklin against the rest of Kentucky

pH 6.45 is 0.66 above the Kentucky median of 5.79. 113 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: Bourbon (6.37), Fayette (6.39), Harrison (6.4), Bath (6.43), Anderson (6.47), Fulton (6.48), Jessamine (6.5), Woodford (6.53).

The range in Kentucky runs from Greenup at 5.09 to Carroll at 6.63; Franklin sits 88% of the way up.