Soil pH in Sussex, DE: Lime or Sulfur?

Typical topsoil pH in Sussex, DE

Typical topsoil in Sussex, DE is pH 5.79, just outside the 6-7 range for vegetable garden. Test first; it may need nothing.

What Sussex 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 2.1 lb/100 sq ft.
• Sulfur: blueberries 1 lb/100 sq ft; blue hydrangeas 0.6 lb/100 sq ft.

What to do next

If your test lands near 5.79, 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 439,956 surveyed acres in Sussex, DE, 73% are moderately acidic (5.5-6.5), 23% are strongly acidic (below 5.5), 3% are alkaline (above 7.3), 2% are near neutral (6.5-7.3). Mapped soils run from pH 4 to 8, a spread of 4 units across 407 soil components. 73% 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 7.5% clay and 3.08% organic matter, which this site treats as sandy. Moving it one pH unit takes about 3 lb of lime or 1.2 lb of sulfur per 100 sq ft. 3% of mapped components carry free carbonate (lime already in the ground).

Sussex against the rest of Delaware

pH 5.79 is right at the Delaware median of 5.75. 2 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), Kent (5.75).