pH
pH is the measure of soil's acidity or alkalinity, measured on a scale of 1 to 14. Water is considered neutral at pH 7.pH levels below 7 are classified as acidic, or "sour". Levels above 7 are basic, alkaline or "sweet".
Most plants prefer a slightly acidic soil pH of 6.0 to 6.5.
Modifying soil pH will not occur overnight. It may take one or two years
for the soil pH level to be raised or lowered.
pH--LOWER
Before modifying the soil pH, make sure to have a soil test to determine the current pH.To lower the pH (or make more acidic) by one pH point, supply roughly 15 pounds of garden or elemental sulfur per 1000 square feet, depending on soil type. More sulfur would be needed for clay soils; less for sandy types. Incorporate the sulfur into the soil or spread on top of the ground. Water well.
It may take a year or two for the soil pH to reflect the change.
The use of pine needles and peat moss will also acidify the soil, though
it is difficult to state accurate amounts needed.
pH--RAISING
Before modifying the soil pH, make sure to have a soil test to determine the current pH.To raise the pH (or make more alkaline) by one point, supply roughly 120 pounds of garden limestone per 1000 square feet. Incorporate into the soil or spread uniformly on top of the ground. Water well.
It may take a year or two for the soil pH to reflect the change.