What is Acid Soil?

Acid soil is soil which has a low pH, indicating that it is on the acidic side of neutral. Gardeners can determine soil pH with home testing kits, or by sending samples to labs which service gardeners, and determinations of soil acidity are a very important part of gardening, because plants respond to changes in soil acidity or alkalinity. Some plants prefer acid soil, while others like a more neutral or alkaline environment, and soil conditions can be an important limitation to think about when gardening.

Soil pH tends to range between five and eight, with five being very acidic for soil. A number of things can influence the balance of the soil, including the compounds present in the soil and amendments added by a gardener, ranging from sand to fertilizer. It is possible to deliberately adjust the pH level of soil to meet the needs of specific plants.

Plants which thrive in acid soil need acidic conditions to live. If they are grown in neutral or alkaline soils, they may not be able to access the nutrients they need. As a result, they will fail to thrive. They may be more prone to developing diseases and infections, in addition to being listless and slow to grow, and the plants may eventually die because the conditions are not optimal. When transplanted to areas with acidic soil, these plants will generally perk up and begin to flourish.

When plants which prefer alkaline or neutral soil are grown in acid soil, they also fail to thrive. The nutrients they need are inaccessible because of the composition of the soil, and they can be prone to health problems. Because gardeners may tend to fertilize when plants start to struggle, the fertilizer may compound the problem by “burning” the plant and creating patches of brown and yellow on the leaves and stems.

If soil tests reveal that soil is more acidic than desired, lime can be added to the soil to make it more alkaline. The lime needs to be worked deeply into the soil and the soil will need to be periodically tested to confirm that the pH is stable. Amendments can also be added to make soil more acidic if gardeners need acid soil. Most garden supply stores carry tools for adjusting soil pH, and some also carry testing kits or have information about labs which can perform soil tests.

Gardeners should get into the habit of checking the pH preferences of plants before they grow them, so that they can select plants which will grow in their soil, and grow well with other plants. Mixing acid-loving and alkaline-loving plants will not work out, because the plants have opposing soil needs.