As the heat of the summer is coming to an end along with the rains we received this season, I happened to look through my gardens I have planted along the edges of my home. Much of my plants have benefitted from the extra moisture and are thriving.
But, I noticed one of my plants being discolored throughout its foliage. The plant is doing fine overall with healthy leaves and has grown throughout the summer, but the color is a concern.
The leaves on this plant are no longer green, but yellow in appearance and have prominent green veining throughout. This yellowing of the leaves is not a disease but a nutrient deficiency called iron chlorosis. Iron chlorosis is a deficiency of iron within the plant. While the deficiency looks rather concerning and can lead to degraded plant health and leaf decay, it is not a disease and can be treated.
According to Natalie Goldberg, a New Mexico State University plant pathologist, iron chlorosis is the leading landscape concern in New Mexico and is typically presented in early spring when leaves are emerging from the plant.
As the summer months’ progress, untreated plants can develop a sickly appearance with brown and dying leaf spots. Leaves can also progress from a yellow color to a white color (Goldberg, 2017). Iron deficiency along with the environmental stressors we have experienced with our weather could have your plants looking like mine.
Goldberg also explains some of the most common plants submitted for testing for iron deficiency include photinia, willows, mulberry, maples, sycamores, poplars, roses, apples, pears, hawthorn, stone fruits and pecan (Goldberg, 2017).
Iron is an important nutrient for plant growth and provides its green color, hence the most common presentation being in spring. James Walworth, a University of Arizona soil extension specialist, says it is common to see a plant presenting an iron deficiency next to a plant that is thriving and healthy. This is because some plants grown and adapted to the area are able to acclimate and pull nutrients from the soil for survival (Walworth, 2013).
While iron is present in our New Mexico soils, our alkaline soils bind the iron, making it unavailable to plants. When untreated, plants can eventually die back and/or die completely. To turn the deficiency of iron to an efficiency does not require a huge effort on your part.
Iron can be purchased at your local garden store and/or online and should be chelated iron. Chelated iron allows the iron to be available to the plant. Fe-EDDHA is the most effective chelated iron source for our alkaline soils and can be applied directly to the soil (Walworth, 2013).
Foliar applications are the best, avoiding the issue of high pH soils’ binding the iron you apply directly to the soil. This strategy is best used in spring and when temperatures are below 85 degrees Fahrenheit. If temperatures are above 85 degrees, leaf burning could occur and the iron should be applied to the soil.
Overall, iron chlorosis is an iron deficiency that is very common throughout our New Mexico landscape plants. The deficiency can cause yellowing of the leaves with green veins, but ultimately cause decreased plant health and even death of the plant in extreme cases left untreated.
Reversing the deficiency is fairly easy with products available at most retail nurseries, garden departments, and online. For more information on iron chlorosis, please reach out to the Valencia County Extension Office or fread the publications linked below.
NMSU Iron Chlorosis: aces.nmsu.edu/pubs/_h/H171/welcome.html
UA Recognizing and Treating Iron Deficiency in the Home Yard: extension.arizona.edu/sites/extension.arizona.edu/files/pubs/az1415.pdf
For more information visit the NMSU Publication site: extension.nmsu.edu
Free virtual classes are offered the first and third Wednesday of the month from 3-4 p.m. with Ready, Set, GROW!
To register for an upcoming program, call the Valencia County Cooperative Extension Service at 505-565-3002. For more information, visit valenciaextension.nmsu.edu.