Soil pH in Lawrence, PA: Lime or Sulfur?

Typical topsoil pH in Lawrence, PA

Typical topsoil in Lawrence, PA is pH 5.84, just outside the 6-7 range for vegetable garden. Test first; it may need nothing.

What Lawrence 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 4.9 lb/100 sq ft.
• Sulfur: blueberries 1.8 lb/100 sq ft; blue hydrangeas 1.4 lb/100 sq ft.

What to do next

If your test lands near 5.84, 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 217,405 surveyed acres in Lawrence, PA, 69% are moderately acidic (5.5-6.5), 24% are strongly acidic (below 5.5), 6% are near neutral (6.5-7.3), 1% are alkaline (above 7.3). Mapped soils run from pH 4.1 to 7.5, a spread of 3.4 units across 275 soil components. 69% 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 16.9% clay and 3.04% 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. 1% of mapped components carry free carbonate (lime already in the ground).

Lawrence against the rest of Pennsylvania

pH 5.84 is 0.53 above the Pennsylvania median of 5.31. 61 of 67 Pennsylvania counties have more acidic topsoil. Nationally it is more acidic than the US county median of 6.05.

Closest in pH within the state: Lehigh (5.77), Adams (5.78), Chester (5.79), Lancaster (5.81), Delaware (5.86), Montgomery (5.91), Bucks (5.92), Washington (6.04).

The range in Pennsylvania runs from Forest at 4.57 to Greene at 6.07; Lawrence sits 85% of the way up.