Later, the terminal and lateral buds die. This is rare, as the azaleas require very little calcium. High levels of calcium inhibit the distribution of iron, resulting in iron chlorosis and the accumulation of iron along veins. Mature leaves seldom recover from the chlorosis. Magnesium Symptoms are chlorosis of older leaves, beginning at the leaf tips.
Veins remain green at first but later lose color.
Brown, dead areas appear on the tips and margins of lower leaves which soon drop off. They may develop reddish purple blotches on their upper surfaces. While azaleas apparently require more magnesium than calcium, that amount is small compared to other plants. Iron Iron deficiency causes interveinal chlorosis of young leaves, with young leaves becoming yellow, cream colored or white while the veins remain green. The lower leaves are the last to be affected.