|Iron chlorosis on maple leaves|
Some environmental conditions can cause or aggravate iron chlorosis because they interfere with normal plant functions, including the uptake of nutrients. Overwatering is probably the most common cause of iron chlorosis symptoms in the landscape. While water is essential, too much drives out soil oxygen and kills or damages roots. Dead roots means no (or reduced) nutrient absorption.
Soil compaction, the pressing together of soil particles, is another common cause. Compaction reduces the amount of oxygen and water penetration into the soil. It increases the amount of runoff and heat conductivity. You guessed it: this kills or injures roots, making it tough to perform their water and nutrient absorption job!
So what is a plant owner to do?
• Avoid planting species that are very susceptible to iron chlorosis including silver and amur maple and pin oak. Aspen, cherry and birch are also susceptible.
• Add organic matter to the soil before planting to help improve soil condition. Plant based compost is best. For more information: http://www.ext.colostate.edu/pubs/garden/07235.html
• Core aerate turf and around the base of affected vegetation to increase water and oxygen penetration.
• Apply iron to the soil or plant. Recommended techniques work better in some situations than others, depending on the plant, soil condition and severity of the problem.
For specific instructions on iron applications, see this fact sheet published by Utah State University: