Soil pH in Macomb, MI: Lime or Sulfur?

Typical topsoil pH in Macomb, MI

Typical topsoil in Macomb, MI is pH 6.8, already right for vegetable garden (6-7). Test before adding anything.

What Macomb needs, by plant

• Already in range: lawn (cool-season grass), vegetable garden, tomatoes, roses.
• Sulfur: potatoes 3 lb/100 sq ft over 2 applications; strawberries 1.8 lb/100 sq ft; blueberries 4.1 lb/100 sq ft over 3 applications; azaleas and rhododendrons 3.5 lb/100 sq ft over 2 applications; blue hydrangeas 3.5 lb/100 sq ft over 2 applications; pink hydrangeas 1.2 lb/100 sq ft.

What to do next

If your test lands near 6.8, you can skip lime and sulfur for lawn (cool-season grass), vegetable garden, tomatoes, roses.

How mixed the soil is

Of the 296,561 surveyed acres in Macomb, MI, 38% are moderately acidic (5.5-6.5), 37% are near neutral (6.5-7.3), 25% are alkaline (above 7.3). Mapped soils run from pH 4.7 to 8.2, a spread of 3.5 units across 527 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 18.4% clay and 3.51% 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. 3% of mapped components carry free carbonate (lime already in the ground).

Macomb against the rest of Michigan

pH 6.8 is 0.76 above the Michigan median of 6.04. 76 of 83 Michigan counties have more acidic topsoil. Nationally it is more alkaline than the US county median of 6.05.

Closest in pH within the state: Shiawassee (6.57), Lenawee (6.61), Monroe (6.67), Gratiot (6.78), Sanilac (6.91), Wayne (6.93), Tuscola (6.95), Bay (6.96).

The range in Michigan runs from Baraga at 4.72 to Huron at 7.03; Macomb sits 90% of the way up.