Iron for Grass that Looks Dead

Cause

• The lack of iron in grass, or iron chlorosis, occurs when green chlorophyll in grass blades does not develop adequately. Iron is among the essential nutrients required by grass blades for synthesizing the molecules of chlorophyll. Iron deficiency may be because the soil is deficient in the nutrient or because an excessive amount of another nutrient, such as bicarbonate or phosphate, is affecting the ability of grass to absorb iron.

Symptoms

• Early symptoms of iron deficiency is a yellowing of leaf blades. The usual dark green color of grass reduces to lighter green or yellowish green. The discoloration may be interveinal, giving leaf blades a distinctly striped look. As the damage gets worse, grass starts to turn yellow or white and dies entirely. Dying grass appears on the lawn in irregular patterns.

Remedy

• The use of chelated iron fertilizers are considered among the most appropriate material to apply on iron-deficient grass. In these fertilizes, iron is mixed with the chemical chelate that helps keep the nutrient in plant-accessible form. The use of non-chelated iron fertilizers is not recommended, especially in soil with high pH levels, because the iron becomes unavailable to the grass. Chelated iron fertilizers include Fe-DTPA, Fe-EDTA and Fe-EDDHA.

Cultural Management

• Improve the condition of your grass to help prevent an iron deficiency from occurring. This includes keeping the lawn well aerated by reducing compaction and avoiding excessive use of water. Reduce soil pH in alkaline soil by adding elemental sulfur. Recommended rates of application are 5 to 20 lbs. of elemental sulfur for every 1,000 square feet of grass to reduce iron chlorosis. In lawns with deficiency, choose the more acidifying nitrogen sources like ammonium sulfate.