Soil pH in Dallas, TX: Lime or Sulfur?

Typical topsoil pH in Dallas, TX

Typical topsoil in Dallas, TX is pH 7.75 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 Dallas 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 7.75, consider raised beds for anything acid-loving; with 83% of soils here carrying free lime, sulfur will not hold.

How mixed the soil is

Of the 398,049 surveyed acres in Dallas, TX, 83% are alkaline (above 7.3), 10% are near neutral (6.5-7.3), 7% are moderately acidic (5.5-6.5). Mapped soils run from pH 5.5 to 8.2, a spread of 2.7 units across 84 soil components. 83% 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 45.1% clay and 2.14% organic matter, which this site treats as clay. Moving it one pH unit takes about 11.5 lb of lime or 3.4 lb of sulfur per 100 sq ft. 83% of mapped components carry free carbonate (lime already in the ground), enough that sulfur gets neutralised before it does much.

Dallas against the rest of Texas

pH 7.75 is 0.32 above the Texas median of 7.43. 200 of 254 Texas counties have more acidic topsoil. Nationally it is more alkaline than the US county median of 6.05.

Closest in pH within the state: Bandera (7.73), Mitchell (7.73), Ward (7.73), McCulloch (7.74), Hutchinson (7.75), Taylor (7.75), Borden (7.76), Comal (7.76).

The range in Texas runs from Hardin at 4.64 to Upton at 8.19; Dallas sits 88% of the way up.