How Does High pH Affect Plant Growth

Major effects of extremes in pH levels include gaps in nutrient availability and the presence of high concentrations of minerals that are harmful to plants. In very alkaline soil, certain micronutrients such as zinc and copper become chemically unavailable to plants.

What happens to plants if pH is too high?

Plants only take up dissolved nutrients through their roots. When the media-pH is too high, micronutrients (especially iron) are less soluble and unavailable for uptake by plant roots. High-pH induced iron deficiency can develop within one to two weeks, resulting in chlorosis of new growth and overall stunting.

Is high pH good for plants?

When a plant’s soil pH increases, which is what would happen when its food’s pH is too high, the plant’s ability to absorb certain nutrients is disrupted. As a result, some nutrients cannot be absorbed properly. … The soil’s high pH prevents the iron present in the soil from changing into a form the plant can absorb.