Soil pH in Amador, CA: Lime or Sulfur?

Typical topsoil pH in Amador, CA

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

What Amador needs, by plant

• Already in range: lawn (cool-season grass), vegetable garden, potatoes, strawberries, roses, azaleas and rhododendrons, pink hydrangeas.
• Just outside, test first: tomatoes (off by 0.2).
• Sulfur: blueberries 2.3 lb/100 sq ft over 2 applications; blue hydrangeas 1.8 lb/100 sq ft.

What to do next

If your test lands near 6, you can skip lime and sulfur for lawn (cool-season grass), vegetable garden, tomatoes, potatoes, strawberries, roses, azaleas and rhododendrons, pink hydrangeas.

How mixed the soil is

Of the 262,645 surveyed acres in Amador, CA, 90% are moderately acidic (5.5-6.5), 6% are strongly acidic (below 5.5), 4% are near neutral (6.5-7.3). Mapped soils run from pH 4.5 to 7.5, a spread of 3 units across 324 soil components. 90% 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 15.9% clay and 3.87% 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. 7% of mapped components carry free carbonate (lime already in the ground).

Amador against the rest of California

pH 6 is 0.54 below the California median of 6.54. 3 of 58 California counties have more acidic topsoil. Nationally it is more acidic than the US county median of 6.05.

Closest in pH within the state: Del Norte (5.43), Humboldt (5.75), Mariposa (5.87), Tuolumne (6.02), El Dorado (6.04), Nevada (6.04), Mendocino (6.05).

The range in California runs from Del Norte at 5.43 to Imperial at 8.16; Amador sits 21% of the way up.