Magnesium Deficiency

Magnesium deficiency manifests as chlorosis between the veins of older leaves, while the veins remain green. As the deficiency progresses, the leaves may turn brown and wither; this problem often occurs with high potassium fertilization. Before supplementing with magnesium, consider the pH, previous fertilization, and soil fertility. Magnesium sulfate can correct a confirmed deficiency, but an excess of it limits calcium uptake, and a spray that is too concentrated can damage the leaves.