Garden Minute - Iron Chlorosis

June 30, 2015

This is Jason Lamb with your Gardening Minute.

Iron chlorosis is the most common micro-nutrient problem of ornamentals, shrubs, and trees in Quay County. Leaves in affected plants turn light green, to yellow, then to white with distinct green veins in the leaf.  In severe cases, the leaves may be entirely white. The margins of severely affected leaves often scorch and die during hot weather. 

Iron chlorosis is the result of the inability of the plant to extract sufficient iron from the soil. Iron is often plentiful in the soil, but it is tightly bound to the soil particles in high pH soils. Preventing and controlling iron chlorosis is difficult. When irrigating, growers should wet the root zone and then given time to dry out before the next irrigation. This allows iron to be more readily available to the plant.  

Numerous iron chelate compounds are available for treating iron chlorosis and should be applied in the spring when the iron is readily taken up by the newly developing foliage. Once the foliage is fully developed, iron will not be readily taken up by the leaves. Treatments later in the growing season should be made with soil applied chelated iron. Any foliar applications should not be made when the temperature is over 85 degrees, as the chemical will burn the foliage. High temperatures will also affect the ability of roots to absorb the nutrient; therefore, soil applications during hot weather are less effective. 

If you would like more information on iron chlorosis please contact the Extension office at 461-0562. This has been your Gardening Minute with Jason Lamb your Quay County Ag. Extension Agent. Where are programs are open to everyone.