Soil pH in Madison, VA: Lime or Sulfur?

Typical topsoil pH in Madison, VA

Typical topsoil in Madison, VA is pH 5.29, too acidic for vegetable garden. Expect roughly 8.4 lb of lime per 100 sq ft, but only after a soil test confirms it.

What Madison 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) 8.4 lb/100 sq ft over 2 applications; vegetable garden 8.4 lb/100 sq ft over 2 applications; tomatoes 8.4 lb/100 sq ft over 2 applications; roses 8.4 lb/100 sq ft over 2 applications; pink hydrangeas 7 lb/100 sq ft over 2 applications.

What to do next

If your test confirms pH near 5.29, spread about 84 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 147,577 surveyed acres in Madison, VA, 58% are strongly acidic (below 5.5), 42% are moderately acidic (5.5-6.5). Mapped soils run from pH 4.6 to 6.2, a spread of 1.6 units across 170 soil components. No single class covers 60% of the county, so two gardens a few miles apart here can need opposite treatments. Test your own bed.

Clay, organic matter and rates

Topsoil here averages 16.8% clay and 2.28% 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.

Madison against the rest of Virginia

pH 5.29 is 0.05 above the Virginia median of 5.24. 76 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: Botetourt (5.27), Giles (5.28), Rockingham (5.28), Dinwiddie (5.29), Petersburg City (5.29), Scott (5.32), Wythe (5.32), Bedford (5.33).

The range in Virginia runs from Newport News City at 4.76 to Poquoson City at 6.36; Madison sits 33% of the way up.