Soil pH in Kent, DE: Lime or Sulfur?

Typical topsoil pH in Kent, DE

Typical topsoil in Kent, DE is pH 5.75, too acidic for vegetable garden. Expect roughly 5.6 lb of lime per 100 sq ft, but only after a soil test confirms it.

What Kent needs, by plant

• Already in range: potatoes, strawberries, azaleas and rhododendrons.
• Lime: lawn (cool-season grass) 5.6 lb/100 sq ft over 2 applications; vegetable garden 5.6 lb/100 sq ft over 2 applications; tomatoes 5.6 lb/100 sq ft over 2 applications; roses 5.6 lb/100 sq ft over 2 applications; pink hydrangeas 3.5 lb/100 sq ft.
• Sulfur: blueberries 1.8 lb/100 sq ft; blue hydrangeas 1.2 lb/100 sq ft.

What to do next

If your test confirms pH near 5.75, spread about 56 lb of ground limestone per 1,000 sq ft of vegetable bed in 2 doses, ideally in fall.

How mixed the soil is

Of the 309,369 surveyed acres in Kent, DE, 69% are moderately acidic (5.5-6.5), 31% are strongly acidic (below 5.5). Mapped soils run from pH 4 to 6.7, a spread of 2.7 units across 388 soil components. 69% 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 10.7% clay and 2.78% 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.

Kent against the rest of Delaware

pH 5.75 is right at the Delaware median of 5.75. 1 of 3 Delaware counties have more acidic topsoil. Nationally it is more acidic than the US county median of 6.05.

Closest in pH within the state: New Castle (5.73), Sussex (5.79).

The range in Delaware runs from New Castle at 5.73 to Sussex at 5.79; Kent sits 33% of the way up.