Soil pH in Roanoke City, VA: Lime or Sulfur?

Typical topsoil pH in Roanoke City, VA

Typical topsoil in Roanoke City, VA is pH 5.13, 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 Roanoke City 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 7.7 lb/100 sq ft over 2 applications.

What to do next

If your test confirms pH near 5.13, 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 14,281 surveyed acres in Roanoke City, VA, 82% are strongly acidic (below 5.5), 12% are moderately acidic (5.5-6.5), 6% are near neutral (6.5-7.3). Mapped soils run from pH 4.6 to 7.3, a spread of 2.7 units across 71 soil components. 82% 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 17.8% clay and 1.59% 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.

Roanoke City against the rest of Virginia

pH 5.13 is 0.11 below the Virginia median of 5.24. 44 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: Augusta (5.12), Nelson (5.12), Hopewell City (5.12), Chesterfield (5.13), Carroll (5.14), Stafford (5.15), Clifton Forge City (5.15), Appomattox (5.17).

The range in Virginia runs from Newport News City at 4.76 to Poquoson City at 6.36; Roanoke City sits 23% of the way up.