Treatment of Iron Chlorosis on Landscape Plantings

Description of Plant Symptoms:  Affected leaves turn a yellowish color while the leaf veins remain a dark green. Iron chlorosis is caused by the plant not being able to obtain the iron it needs. Iron is needed for the production of chlorophyll. Therefore, a lack of iron results in a loss of the green color in the leaves. In severe cases, leaf color may change from yellow to white to brown. If uncorrected twigs and eventually branches may die leading to the death of the tree.

Symptoms may appear over the entire tree, on one side only, or be limited to individual branches.

Soils in Illinois usually have adequate amounts of mineral iron. However, as soil pH rises above 7.0, iron changes to an insoluble form that many plants have difficulty picking up.

What We Do: Soil Treatment - Lowering the soil pH is a more permanent way of correcting iron chlorosis caused by high pH soils. Unfortunately this is also one of the most difficult treatment methods because it is almost impossible to lower the soil pH significantly to depths of 10 to 24 inches.

A more feasible approach is to add iron to the soil in sufficient quantity to increase the amount available to roots. Our application mixes sulfur and iron chelate at a specific ratio achieving both effects. Treatment is made by drill holes into the soil, not the tree. The sulfur lowers the pH in a small area and makes the iron more available to the tree. The iron chelate provides instant iron to the tree creating a dramatic green up in 30-45 days.

All you need to do is water the area under treated trees and shrubs for about 2 hours after the application has been made. To do this we recommend the use of an oscilating sprinkler. This treatment will last from 1 to 5 years depending on soil conditions.