Macronutrient - The element, magnesium (Mg), is a building block of the chlorophyll molecule. Therefore, it is essential for the photosynthesis process. It also helps to activate certain plant enzymes necessary for plant growth.

Sources - The soil contains magnesium as does organic matter and dolomitic limestone.

Note: We have provided some general information and observations on this topic aimed at the home gardener. Before you take any serious action in your landscape, check with your state's land grant university's Cooperative Extension Service for the most current, appropriate, localized recommendations.