Soil pH in Rio Blanco, CO: Lime or Sulfur?

Typical topsoil pH in Rio Blanco, CO

Typical topsoil in Rio Blanco, CO is pH 7.36 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 Rio Blanco 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 7.36, consider raised beds for anything acid-loving; with 53% of soils here carrying free lime, sulfur will not hold.

How mixed the soil is

Of the 1,733,505 surveyed acres in Rio Blanco, CO, 52% are alkaline (above 7.3), 40% are near neutral (6.5-7.3), 7% are moderately acidic (5.5-6.5), 1% are strongly acidic (below 5.5). Mapped soils run from pH 5 to 8.8, a spread of 3.8 units across 1,352 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 19% clay and 1.97% 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. 53% of mapped components carry free carbonate (lime already in the ground), enough that sulfur gets neutralised before it does much.

Rio Blanco against the rest of Colorado

pH 7.36 is 0.19 above the Colorado median of 7.17. 42 of 63 Colorado counties have more acidic topsoil. Nationally it is more alkaline than the US county median of 6.05.

Closest in pH within the state: Broomfield (7.29), Weld (7.29), Kit Carson (7.33), Cheyenne (7.35), Montezuma (7.39), Saguache (7.39), Lincoln (7.41), Pitkin (7.44).

The range in Colorado runs from San Juan at 5.53 to Alamosa at 8.28; Rio Blanco sits 67% of the way up.