Soil pH in Culpeper, VA: Lime or Sulfur?

Typical topsoil pH in Culpeper, VA

Typical topsoil in Culpeper, VA is pH 5.07, too acidic for vegetable garden. Expect roughly 9.8 lb of lime per 100 sq ft, but only after a soil test confirms it.

What Culpeper needs, by plant

• Already in range: potatoes, blueberries, azaleas and rhododendrons, blue hydrangeas.
• Lime: lawn (cool-season grass) 9.8 lb/100 sq ft over 2 applications; vegetable garden 9.8 lb/100 sq ft over 2 applications; tomatoes 9.8 lb/100 sq ft over 2 applications; strawberries 6.3 lb/100 sq ft over 2 applications; roses 9.8 lb/100 sq ft over 2 applications; pink hydrangeas 8.4 lb/100 sq ft over 2 applications.

What to do next

If your test confirms pH near 5.07, spread about 98 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 205,165 surveyed acres in Culpeper, VA, 79% are strongly acidic (below 5.5), 21% are moderately acidic (5.5-6.5). Mapped soils run from pH 4.3 to 6.2, a spread of 1.9 units across 176 soil components. 79% 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 16.6% clay and 1.82% 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.

Culpeper against the rest of Virginia

pH 5.07 is 0.17 below the Virginia median of 5.24. 38 of 127 Virginia counties have more acidic topsoil. Nationally it is more acidic than the US county median of 6.05.

Closest in pH within the state: Waynesboro City (5.03), Martinsville City (5.05), Amelia (5.06), Hanover (5.06), Henrico (5.09), Prince William (5.09), Augusta (5.12), Nelson (5.12).

The range in Virginia runs from Newport News City at 4.76 to Poquoson City at 6.36; Culpeper sits 19% of the way up.