Soil pH in Calvert, MD: Lime or Sulfur?

Typical topsoil pH in Calvert, MD

Typical topsoil in Calvert, MD is pH 5.31, too acidic for vegetable garden. Expect roughly 3.6 lb of lime per 100 sq ft, but only after a soil test confirms it.

What Calvert needs, by plant

• Already in range: potatoes, blueberries, azaleas and rhododendrons, blue hydrangeas.
• Just outside, test first: strawberries (off by 0.2).
• Lime: lawn (cool-season grass) 3.6 lb/100 sq ft; vegetable garden 3.6 lb/100 sq ft; tomatoes 3.6 lb/100 sq ft; roses 3.6 lb/100 sq ft; pink hydrangeas 2.7 lb/100 sq ft.

What to do next

If your test confirms pH near 5.31, spread about 36 lb of ground limestone per 1,000 sq ft of vegetable bed, ideally in fall.

How mixed the soil is

Of the 135,084 surveyed acres in Calvert, MD, 65% are strongly acidic (below 5.5), 32% are moderately acidic (5.5-6.5), 4% are near neutral (6.5-7.3). Mapped soils run from pH 3.6 to 7.2, a spread of 3.6 units across 192 soil components. 65% 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 9.7% clay and 3.27% 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. None of the mapped components carry free carbonate.

Calvert against the rest of Maryland

pH 5.31 is 0.18 below the Maryland median of 5.49. 7 of 24 Maryland counties have more acidic topsoil. Nationally it is more acidic than the US county median of 6.05.

Closest in pH within the state: Allegany (5), Baltimore City (5.03), Anne Arundel (5.05), St. Mary's (5.2), Harford (5.33), Somerset (5.35), Montgomery (5.47), Cecil (5.48).

The range in Maryland runs from Charles at 4.47 to Washington at 6.01; Calvert sits 55% of the way up.