The quality of plant growth and reproduction is affected by the pH level of the soil and the requirements vary depending on the plants themselves. The pH value is directly related to how available nutrients in the soil are for the plants. Different plants require different pH levels. Azaleas and blueberries are at their best in acidic soils with a pH between 5 and 5.5. Grasses, ornamental flowers, and vegetables prefer a slightly acidic soil with a pH between 5.8 and 6.5. Nutrient deficiencies may result of the soil pH is above or below the recommended range.

Soil pH values above or below these ranges may result in less vigorous growth and nutrient deficiencies.

Three are 3 categories of nutrients required for healthy, productive plants and vegetables. Nitrogen, phosphorus and potassium are the primary nutrients and are needed in much larger quantities than other the secondary or micronutrients. The secondary nutrients, magnesium, sulfur, and calcium are needed in much smaller quantities but are still very important to the health of the plants. The micronutrients, manganese and zinc are required in small amounts. For the most part secondary and micronutrients can be controlled by maintaining the soil pH at the proper level. The primary nutrients are controlled by adding fertilizer.

Plant growth is impacted by the availability of nutrients which is affected by the extremes of the pH. Some nutrients become toxic to plants when they are more available to them such as aluminum or manganese in highly acidic soils. At low pH values, calcium, phosphorus and magnesium become less available for the plant to take up. When the soil pH is above 6.5, most of the micronutrients are less available to the plants.