Soil pH in Lemhi, ID: Lime or Sulfur?

Typical topsoil pH in Lemhi, ID

Typical topsoil in Lemhi, ID is pH 7.29 and calcareous, so sulfur won't lower it for long. For vegetable garden, choose alkaline-tolerant varieties and add compost rather than fighting the soil.

What Lemhi needs, by plant

• Beds or pots instead: lawn (cool-season grass), vegetable garden, tomatoes, potatoes, strawberries, roses, blueberries, azaleas and rhododendrons, blue hydrangeas, pink hydrangeas.

What to do next

If your test confirms pH near 7.29, consider raised beds for anything acid-loving; with 44% of soils here carrying free lime, sulfur will not hold.

How mixed the soil is

Of the 812,054 surveyed acres in Lemhi, ID, 45% are alkaline (above 7.3), 41% are near neutral (6.5-7.3), 14% are moderately acidic (5.5-6.5). Mapped soils run from pH 5 to 9.1, a spread of 4.1 units across 414 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 17.2% clay and 2.55% 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. 44% of mapped components carry free carbonate (lime already in the ground), enough that sulfur gets neutralised before it does much.

Lemhi against the rest of Idaho

pH 7.29 is 0.28 above the Idaho median of 7.01. 31 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: Elmore (7.26), Franklin (7.26), Twin Falls (7.27), Jerome (7.29), Minidoka (7.34), Payette (7.36), Custer (7.37), Madison (7.37).

The range in Idaho runs from Valley at 6.04 to Jefferson at 8.06; Lemhi sits 62% of the way up.