Iron Chlorosis Takes its Toll on Landscape Plants

Iron chlorosis on a sweetgum leaf
(Photo: NMSU-PDC)

As the temperatures begin to rise many of our landscape plants will begin to show symptoms of environmental stresses. One of the most common landscape disorders in New Mexico is iron deficiency, also called iron chlorosis. Iron deficiency symptoms typically begin in spring when the plants are leafing out. As summer progresses,
plants left untreated may exhibit severe symptoms and have an overall unthrifty appearance.

Iron Deficiency is one of the most common nutrient deficiencies in 
all sorts of landscape plants. Some of the most commonly submitted plants for diagnosis include: Photinia, willows, mulberry, maples, sycamore, Poplars, roses, apples, pears, Hawthorne, stone fruits and pecan. Iron is a critical element for good growth and green color. Iron may be plentiful in the soil, but it is tightly bound to the soil particles in high pH (alkaline and calcareous) soils. Under these conditions, the iron is 

Iron chlorosis on Photinia shrub>
(Photo: NMSU-PDC)

unavailable for plant use.

The classic symptom of iron deficiency is interveinal chlorosis where the leaf turns yellow and the veins remain green. In very severe cases, leaves may turn white in color or develop necrotic spots,
which can look like a fungal infection, on the affected leaves. Over time, plants which remain untreated will start to dieback, become unsightly in appearance and may eventually die. Symptoms can be exacerbated when shrubs are planted in heavy, poorly drained soils

Iron chlorosis on a
Bradford pear tree
(Photo: NMSU-PDC)

Dieback on Bradford pear
caused by iron deficiency
(Photo: NMSU-PDC)