Soil pH in Benewah, ID: Lime or Sulfur?

Typical topsoil pH in Benewah, ID

Typical topsoil in Benewah, ID is pH 6.49, already right for vegetable garden (6-7). Test before adding anything.

What Benewah needs, by plant

• Already in range: lawn (cool-season grass), vegetable garden, tomatoes, strawberries, roses, pink hydrangeas.
• Sulfur: potatoes 2.3 lb/100 sq ft over 2 applications; blueberries 3.5 lb/100 sq ft over 2 applications; azaleas and rhododendrons 2.8 lb/100 sq ft over 2 applications; blue hydrangeas 2.8 lb/100 sq ft over 2 applications.

What to do next

If your test lands near 6.49, 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 220,527 surveyed acres in Benewah, ID, 79% are near neutral (6.5-7.3), 21% are moderately acidic (5.5-6.5). Mapped soils run from pH 4.8 to 7.3, a spread of 2.5 units across 178 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 8.2% clay and 5.08% organic matter, which this site treats as loam. At 5.08% organic matter the soil buffers like a heavier one, which pushes it into the loam bracket. 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.

Benewah against the rest of Idaho

pH 6.49 is 0.52 below the Idaho median of 7.01. 11 of 44 Idaho counties have more acidic topsoil. Nationally it is more alkaline than the US county median of 6.05.

Closest in pH within the state: Fremont (6.42), Kootenai (6.44), Idaho (6.46), Lewis (6.46), Camas (6.49), Caribou (6.53), Adams (6.63), Nez Perce (6.7).

The range in Idaho runs from Valley at 6.04 to Jefferson at 8.06; Benewah sits 22% of the way up.