Maple Iron Deficiency

Maple Tree Iron Chlorosis

We have noticed several trees throughout our community beginning to turn yellow during the summer. This is caused by an iron deficiency call iron chlorosis, which is fairly common in Colorado due to our highly alkaline soil. The iron may be present in the soil but unavailable for the tree to absorb. This gets progressively worse each year and without regular treatment for the rest of the life of the tree, the tree will die.

“The primary symptoms of iron deficiency are interveinal chlorosis, a general yellowing of leaves with veins remaining green. In severe cases, leaves may become pale yellow or whitish, but veins retain a greenish cast.”

If you would like to help your trees, we generally recommend having a qualified arborist come take a look at your trees. We have had good experience with Davey Tree and SavATree.

Treatment options include:

Method	Advantages	Disadvantages
Soil application: Iron sulfate-elemental sulfur	Lasts up to several years Relatively inexpensive No injury to plant Simple procedure	Slow response Results sometimes variable Too expensive for large areas of low-value crops Can be labor-intensive
Soil application: Iron chelates	Simple procedure Generally no injury to plant Relatively quick response	May last less than one season Expensive Results sometimes variable
Foliar application: Chelates or iron sulfate	Quick response Fairly simple, easy procedure (except for large trees)	Only practical method for field crops Expensive on trees Can cause temporary leaf burning Often lasts less than one season
Trunk injection or implantation	Lasts up to several years Moderate expense	Injures tree’s trunk Can’t be used on shrubs or non-woody plants Results sometimes variable Can cause temporary leaf burning Somewhat complicated procedure

You can read more about iron chlorosis and various treatment options on the CSU Extension website here.