Soil pH in San Benito, CA: Lime or Sulfur?

Typical topsoil pH in San Benito, CA

Typical topsoil in San Benito, CA is pH 6.09, already right for vegetable garden (6-7). Test before adding anything.

What San Benito needs, by plant

• Already in range: lawn (cool-season grass), vegetable garden, strawberries, roses, pink hydrangeas.
• Just outside, test first: tomatoes (off by 0.1), potatoes (off by 0.1), azaleas and rhododendrons (off by 0.1).
• Sulfur: blueberries 2.5 lb/100 sq ft over 2 applications; blue hydrangeas 1.8 lb/100 sq ft.

What to do next

If your test lands near 6.09, 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 22,312 surveyed acres in San Benito, CA, 41% are moderately acidic (5.5-6.5), 39% are near neutral (6.5-7.3), 19% are strongly acidic (below 5.5), 1% are alkaline (above 7.3). Mapped soils run from pH 5 to 8.2, a spread of 3.2 units across 142 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 11.2% clay and 1.94% 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. 0% of mapped components carry free carbonate (lime already in the ground).

San Benito against the rest of California

pH 6.09 is 0.45 below the California median of 6.54. 9 of 58 California counties have more acidic topsoil. Nationally it is more alkaline than the US county median of 6.05.

Closest in pH within the state: El Dorado (6.04), Nevada (6.04), Mendocino (6.05), Sonoma (6.08), Marin (6.11), Placer (6.13), Alpine (6.14), Calaveras (6.17).

The range in California runs from Del Norte at 5.43 to Imperial at 8.16; San Benito sits 24% of the way up.