Does Alkalinity Affect Grass Growth?

pH Level

• The alkalinity level of soil affects grass growth just as it does most species of plants. The pH level of soil is a measurement that ascertains the acidity or alkalinity present in soil, with the scale ranging from 0 to 14. A measurement of 7.0 is considered to be neutral. Numbers below 7.0 indicate various levels of acidity, and numbers higher than 7.0 measure the degree of alkalinity present in grass. The ability of grass to absorb nutrients is dependent on its pH level.

Grass pH Level

• Grass grows best in slightly acidic soil with a pH level ranging from 5.8 to 6.5. Therefore, if grass is planted in alkalinic soil with a pH level in excess of 7.0, grass growth will be adversely affected. The degree to which the grass experiences a loss of vigor in growth is determined by the degree of alkalinity in the earth. A soil pH level of 7.1 will still allow the growth of healthy grass, while a pH level of 13 denotes an alkaline-laden soil in which grass will likely suffer growth problems.

Soil Makeup

• When grass grows in alkaline soil with a pH level above 6.5, the grass has difficulty absorbing important nutrients like phosphorus, zinc and manganese. The pH level of soil depends on the types of rocks that broke down to form the dirt and also on the amount of rainfall in the area. As water seeps through the earth, it snatches away nutrients like magnesium and calcium, while leaving behind acidic elements like iron and aluminum.

Balancing pH

• Gardeners and homeowners should routinely test the alkalinity of the soil where their grass grows. The application of elemental sulfur is called for as a means of reducing alkalinity. However, to avoid damage to turf grass, it should not be utilized at a rate of greater than 10 lbs. per 1,000 square feet. Soils with a significant amount of organic matter do a better job of maintaining a balanced pH level, and organic matter should be introduced at the same time new grass is brought to the soil.