Iron Chlorosis

Iron chlorosis is a common tree health issue causing the leaves to turn yellow. Some of the more sensitive tree species that seem to suffer in our region include silver maples, freeman maples (those wildly popular maples that turn red in the fall), amur maples, river birch, swamp white oaks, and eastern white pines.  It occurs when trees can’t absorb enough iron from the soil to meet their nutritional needs.

The first sign of iron chlorosis is bright yellow leaves with bright green veins, but as the issue worsens, the leaves can turn completely yellow and become almost crispy. If iron is lacking in the leaves, they will not be able to produce chlorophyll, the green pigment that provides energy for photosynthesis.  Iron chlorosis occurs in soils with high pH, soils that are compacted, soils that are poorly drained, and soils with lime. Heavy, clay soils in our area can also be the culprit as maples will have difficulty using iron.

There are different ways to treat a tree suffering from iron chlorosis. Chemical applications or iron in a spray form, injecting iron into the tree, and implanting manganese into the trunk.

You can attempt to prevent iron chlorosis by avoiding overwatering trees, improving drainage, and aerating compact soil around the base of the tree.

It is best to avoid using plastic sheeting under your mulch near trees as it can restrict oxygen movement into the soil.

If left untreated, the leaves may become white and turn to brown followed by the dying back of the branches. Eventually, this will lead to failure and death of the tree.

Iron chlorosis can be difficult to treat. Local tree professionals are knowledgeable and have training and skills for this problem although it is also recommended to study your tree choices prior to planting by avoiding species that are most susceptible.