Soil pH in Valley, MT: Lime or Sulfur?

Typical topsoil pH in Valley, MT

Typical topsoil in Valley, MT is pH 7.19, just outside the 6-7 range for vegetable garden. Test first; it may need nothing.

What Valley needs, by plant

• Just outside, test first: lawn (cool-season grass) (off by 0.2), vegetable garden (off by 0.2), roses (off by 0.2).
• Beds or pots instead: tomatoes, potatoes, strawberries, blueberries, azaleas and rhododendrons, blue hydrangeas, pink hydrangeas.

What to do next

If your test lands near 7.19, you can skip lime and sulfur for lawn (cool-season grass), vegetable garden, roses.

How mixed the soil is

Of the 3,118,118 surveyed acres in Valley, MT, 64% are near neutral (6.5-7.3), 35% are alkaline (above 7.3), 1% are moderately acidic (5.5-6.5). Mapped soils run from pH 5.8 to 9, a spread of 3.2 units across 352 soil components. 64% 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 32.1% clay and 1.76% organic matter, which this site treats as clay. Moving it one pH unit takes about 11.5 lb of lime or 3.4 lb of sulfur per 100 sq ft. 32% of mapped components carry free carbonate (lime already in the ground), enough that sulfur gets neutralised before it does much.

Valley against the rest of Montana

pH 7.19 is 0.11 below the Montana median of 7.3. 21 of 56 Montana counties have more acidic topsoil. Nationally it is more alkaline than the US county median of 6.05.

Closest in pH within the state: Glacier (7.15), Hill (7.17), Phillips (7.17), Blaine (7.19), Chouteau (7.24), Sweet Grass (7.25), Cascade (7.27), Daniels (7.28).

The range in Montana runs from Flathead at 6.02 to Wheatland at 7.77; Valley sits 67% of the way up.