Iron Chlorosis

Key Features


  • Yellowing leaves
  • Dark green veins
  • Premature leaf drop
Iron chlorosis- note the green veins against a light yellow leaf
Darker veins with lighter leaves is a symptom of iron chlorosis
Heavy feeders like Calibrachoa often suffer from iron chlorosis.

Symptoms


Iron chlorosis is a very common nutrient deficiency that is seen in many plants growing under higher pH soil conditions (greater than pH 6.5). Leaves become pale green to yellow, and leaf veins are a darker green. On hot, sunny days the leaf margins can scorch, and leaves drop prematurely.

Iron chlorosis is a regular problem on petunia
Magnesium deficiency is another common nutrient disorder

Biology


Iron chlorosis is the result of a lack of iron in the soil available to the plant. Alkaline soils with a high pH increase the chances of a plant developing iron chlorosis. Though iron deficiency is more common, this problem can occur in conjunction with manganese deficiency and cause similar symptoms. A soil test is needed to conclusively diagnose this problem.

Management Recommendations


The management of iron chlorosis is both difficult and expensive, so prevention through the selection of more tolerant plant species and cultivars is essential. Always check soil pH and submit a leaf sample for analysis. See the links section (the 'i' in the upper left corner of the main page of this app) for a plant diagnostic lab in your state. There are several treatments for the management of iron chlorosis, but these need to be continued on a regular basis and most people find them unsatisfactory in the long-term. Foliar sprays of iron can temporarily remove symptoms but must be applied repeatedly.

Effective Pesticides


Pesticides are neither available nor recommended for managing this condition.

landscape report
Purdue Landscape Report
PPDL
Plant & Pest Diagnostic Laboratory