Soil pH in Grand Isle, VT: Lime or Sulfur?

Typical topsoil pH in Grand Isle, VT

Typical topsoil in Grand Isle, VT is pH 6.51, already right for vegetable garden (6-7). Test before adding anything.

What Grand Isle needs, by plant

• Already in range: lawn (cool-season grass), vegetable garden, tomatoes, roses.
• Just outside, test first: strawberries (off by 0), pink hydrangeas (off by 0).
• Sulfur: potatoes 3.4 lb/100 sq ft over 2 applications; blueberries 5.1 lb/100 sq ft over 3 applications; azaleas and rhododendrons 4.4 lb/100 sq ft over 3 applications; blue hydrangeas 4.4 lb/100 sq ft over 3 applications.

What to do next

If your test lands near 6.51, 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 48,257 surveyed acres in Grand Isle, VT, 84% are near neutral (6.5-7.3), 13% are moderately acidic (5.5-6.5), 2% are strongly acidic (below 5.5). Mapped soils run from pH 5.3 to 7.6, a spread of 2.3 units across 280 soil components. 84% 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 22% clay and 6.31% organic matter, which this site treats as clay. At 6.31% organic matter the soil buffers like a heavier one, which pushes it into the clay bracket. Moving it one pH unit takes about 11.5 lb of lime or 3.4 lb of sulfur per 100 sq ft. None of the mapped components carry free carbonate.

Grand Isle against the rest of Vermont

pH 6.51 is 1.22 above the Vermont median of 5.29. 13 of 14 Vermont counties have more acidic topsoil. Nationally it is more alkaline than the US county median of 6.05.

Closest in pH within the state: Caledonia (5.37), Addison (5.55), Franklin (5.58), Orange (5.7).