Ideal Chemical Levels to Grow a Garden

Soil pH

• The range of soil pH is a scale from 0 to 14. Measurements from 0 to 7 are considered acidic, and alkaline soils have a measurement of 7 to 14. The pH of the soil plays a major role in the ability of plants to take in nutrients and utilize the soil for healthy growth. Unbalanced soil pH is related to problems with plants, including weak, stunted growth or dieback. Most plants thrive in a slightly acidic soil.

Alkaline Soil

• Alkaline soils are those that have a high content of sulfur or those that develop from basic rocks. Desert soils and soils in low-moisture areas tend to be more basic on the pH scale, which means that desert plants like cacti, scrub bushes and desert flowers do well in alkaline soils. Some ornamental and flowering plants, like day lilies, require a soil that tends toward a more neutral to basic pH. Day lilies grow best in soil that ranges from 6.0 to 8.0.

Acidic Soil

• Fruit trees and many flowers prefer a pH that ranges from 4.0 to 6.5. Plants that prefer highly acidic soils, which are closer in measurement to 4.0, include azaleas and hydrangeas, which grow best in soil that has a pH of 4.5 to 6.0. Fruit trees require a great deal of nitrogen to grow, and nitrogen is most easily available in acidic soils. Alkaline soils lack nitrogen, which leads to the production of weak, yellow leaves.

Maintaining Soil pH

• Annual soil tests are crucial to determine whether the chemical level of the soil is adequate for growing plants. The type of plants in the garden change what the pH of the soil should be. Soil pH is increased by the addition of chemicals like lime, including agricultural limestone, according to the Clemson Cooperative Extension. Decreasing the pH of the soil involves ammonium sulfate or sulfur, which helps produce acidity in the soil.