Why is soil pH important?
Nearly all plants prefer the pH to be in the neutral zone (6.5 – 7.5) in order to flourish. Plants are able to absorb and assimilate nutrients much more easily when the soil has the proper pH. Plants suffer in soil with an elevated pH. The Metroplex soil has a naturally high pH arond 8.4. The alkaline soil causes plant growth to be slowed or stunted.
Maintaining proper pH levels in your soil is as important to the overall health of your plants as fertilizing, watering, and pest control. Why? Soil pH affects nutrient availability for one thing. Certain nutrients like iron, copper, and aluminum become less available to plants in alkaline soils and other nutrients such as calcium and phosphorus become less available in moderately acidic soils. For example, the availability of aluminum in acidic soils is what gives hydrangea flowers a blue color. The optimum pH range for most garden plants is between 6.0 and 6.5, slightly acidic. Certain plants, however, prefer more extreme pH conditions. Shrubs such as rhododendrons, azaleas, and blueberries prefer a more acidic soil so be sure to check the preferences of your plants.
Hydrogen ions are involved in numerous chemical interactions, so their presence is beneficial, but in large quantities, ie. acidic soils, they start to dominate the soil colloid. Hydrogen is not considered a plant nutrient and its dominance diminishes the potential storage of ‘real’ plant nutrients. Excess hydrogen also creates highly reactive soils, where miscellaneous chemical reactions become highly probable and compete against plant and microbe requirements. Alkaline soils have no excess hydrogen available, making it difficult for many chemical reactions to occur readily. Soil pH also appears to have a direct impact on minerals with both low and high pH levels limiting their availability. Interestingly, minerals are all available to some degree at pH 6.3 – and curiously, many systems in nature also work optimally around this pH, including plant sap and blood.
