How Does Soil pH Affect Garden Plants

August 19, 2017 in Gardening by Christine

Care About Soil pH – How pH In The Soil Affects Plant Growth

Soil pH rating for healthy plantsIt is important for gardeners to know what soil pH is and how it is affecting their garden plants and lawns. It is necessary to check the soil pH before growing plants in the garden as different plants will have different preferred pH for their proper growth. pH is the short form of “potenz Hydrogen”. This word means the potential to be hydrogen. The soil pH shows how acidic or alkaline the soil is. The pH scale starts from zero and goes to the maximum of 14. Zero represents the most acidic level and 14 shows the most alkaline level. The hydrogen ions in the solution decide the acidity or alkalinity of a solution. An acidic solution will have a higher level of hydrogen ions and alkaline solutions will have lesser hydrogen ions.

Why pH Of Soil Matters?

The soil pH matters to the plant because there are several plant growth factors which get influenced by the soil pH. Soil pH plays an important role in the absorption of nutrients by plants, bacterial growth in the soil, toxic contents in the soil and availability of nutrients. Soil contains bacteria which help in releasing nitrogen contained in dead and decaying organic matter into the soil. These bacteria are more effective in releasing nitrogen an important element needed for plant growth at the optimal pH of 5.5 to 7-0 range. The plant nutrients present in soil will get leached out of the soil only when the pH is below 5-0. Above pH value of 5-0, these nutrients do not get released for plant use. Plants will be able to absorb the nutrients easily only when the pH range is between 5.5 and 6.5. pH also affects the soil structure. Clay soils will be granular in texture and can be easily worked when the pH is in the optimum range of 5.5 -7-0. When the soil is extremely acid or alkaline the clay will be stickier and not appropriate for plant cultivation.

Correcting pH

A soil test will tell you about the pH of the garden soil. By knowing the pH, the gardener can determine whether the soil is apt for growing certain plants or some additions are needed to correct the pH to grow certain produce. Most of the plants will prefer a pH range of 5.5 to 7.0 for their normal growth. The pH levels below 6.0 will affect the availability of nutrients like nitrogen, phosphorous and potassium. When the pH is above 7.5 nutrients like phosphorous, manganese and iron are less available to the plants. Some plants may, however, require more acidic or more alkaline soil for their normal growth. To increase the alkalinity of the soil, usually, lime or dolomite is added. For home gardens, adding ground lime stone and dolomite is the perfect way to make the soil alkaline. If the pH is to be reduced, acid forming materials like sulfur or ammonium sulfate is needed to be applied to the soil. The quantity of the additives will depend on the pH of the soil and the level of correction needed.

Example Of Daylilies pH for Optimum Growth

You can see by the Nutrient availability chart the nutrients available at each pH range. You can also see the nutrients that daylilies take up with a pH of 6.5 to 7.0 is best, they get a good amount the nutrients over 90%, except for aluminium because they are not acid loving plants like azaleas, rhododendrons and camellias and this is why daylilies give the best results at this pH range. By growing a daylily in the 5.0 range you can clearly see by the chart that the daylily plant will not take up its ideal range of nutrients that are needed for good growth. Why does it matter, remember the daylily will not grow anywhere near as good if it is not growing in the correct pH range.

Various factors such as rainfall, soil type, vegetation in the area, temperature, etc., can affect the pH of the soil so check the soil pH before you use them for cultivation. Protection Status