Soil pH in Santa Barbara, CA: Lime or Sulfur?

Typical topsoil pH in Santa Barbara, CA

Typical topsoil in Santa Barbara, CA is pH 6.69, already right for vegetable garden (6-7). Test before adding anything.

What Santa Barbara needs, by plant

• Already in range: lawn (cool-season grass), vegetable garden, tomatoes, roses.
• Just outside, test first: strawberries (off by 0.2), pink hydrangeas (off by 0.2).
• Sulfur: potatoes 2.8 lb/100 sq ft over 2 applications; blueberries 3.9 lb/100 sq ft over 2 applications; azaleas and rhododendrons 3.2 lb/100 sq ft over 2 applications; blue hydrangeas 3.2 lb/100 sq ft over 2 applications.

What to do next

If your test lands near 6.69, you can skip lime and sulfur for lawn (cool-season grass), vegetable garden, tomatoes, strawberries, roses, pink hydrangeas.

How mixed the soil is

Of the 599,049 surveyed acres in Santa Barbara, CA, 37% are moderately acidic (5.5-6.5), 35% are alkaline (above 7.3), 20% are near neutral (6.5-7.3), 9% are strongly acidic (below 5.5). Mapped soils run from pH 5.3 to 9, a spread of 3.7 units across 298 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 2.09% 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. 25% of mapped components carry free carbonate (lime already in the ground).

Santa Barbara against the rest of California

pH 6.69 is 0.15 above the California median of 6.54. 31 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: San Francisco (6.5), Madera (6.58), Solano (6.63), Contra Costa (6.69), Sierra (6.71), Los Angeles (6.72), Fresno (6.75), Siskiyou (6.75).

The range in California runs from Del Norte at 5.43 to Imperial at 8.16; Santa Barbara sits 46% of the way up.