Soil pH in Malheur, OR: Lime or Sulfur?

Typical topsoil pH in Malheur, OR

Typical topsoil in Malheur, OR is pH 7.9 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 Malheur 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 7.9, consider raised beds for anything acid-loving; with 54% of soils here carrying free lime, sulfur will not hold.

How mixed the soil is

Of the 174,727 surveyed acres in Malheur, OR, 87% are alkaline (above 7.3), 13% are near neutral (6.5-7.3). Mapped soils run from pH 7 to 10.1, a spread of 3.1 units across 79 soil components. 87% 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 14.9% clay and 1.33% 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. 54% of mapped components carry free carbonate (lime already in the ground), enough that sulfur gets neutralised before it does much.

Malheur against the rest of Oregon

pH 7.9 is 1.6 above the Oregon median of 6.3. 35 of 36 Oregon counties have more acidic topsoil. Nationally it is more alkaline than the US county median of 6.05.

Closest in pH within the state: Morrow (7.04), Baker (7.1), Lake (7.46), Harney (7.47).