Soil pH in Pottawatomie, OK: Lime or Sulfur?

Typical topsoil pH in Pottawatomie, OK

Typical topsoil in Pottawatomie, OK is pH 6.55, already right for vegetable garden (6-7). Test before adding anything.

What Pottawatomie needs, by plant

• Already in range: lawn (cool-season grass), vegetable garden, tomatoes, roses.
• Just outside, test first: strawberries (off by 0), pink hydrangeas (off by 0).
• Sulfur: potatoes 2.3 lb/100 sq ft over 2 applications; blueberries 3.5 lb/100 sq ft over 2 applications; azaleas and rhododendrons 3 lb/100 sq ft over 2 applications; blue hydrangeas 3 lb/100 sq ft over 2 applications.

What to do next

If your test lands near 6.55, you can skip lime and sulfur for lawn (cool-season grass), vegetable garden, tomatoes, strawberries, roses, pink hydrangeas.

How mixed the soil is

Of the 449,258 surveyed acres in Pottawatomie, OK, 48% are moderately acidic (5.5-6.5), 29% are near neutral (6.5-7.3), 20% are alkaline (above 7.3), 2% are strongly acidic (below 5.5). Mapped soils run from pH 5.3 to 7.9, a spread of 2.6 units across 66 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 17.9% clay and 1.4% 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. 15% of mapped components carry free carbonate (lime already in the ground).

Pottawatomie against the rest of Oklahoma

pH 6.55 is right at the Oklahoma median of 6.55. 38 of 77 Oklahoma counties have more acidic topsoil. Nationally it is more alkaline than the US county median of 6.05.

Closest in pH within the state: Johnston (6.42), Pawnee (6.44), Grady (6.49), Logan (6.52), Grant (6.56), Canadian (6.57), Noble (6.58), Love (6.59).

The range in Oklahoma runs from Adair at 5.12 to Beaver at 7.65; Pottawatomie sits 57% of the way up.