Insufficient iron in the soil is also a problem. In the Chicagoland area, most soils have adequate iron. The problem is the availability of the iron in soil to the plant. In Northeastern Illinois, most soils were formed from limestone bedrock. Thus the chlorosis problem is often due to high soil pH. Herbaceous plants as well as woody plants are susceptible to chlorosis.
Symptoms can vary depending on several factors.
The higher the pH, the more chlorotic the plant. In general, the longer the plant has been chlorotic, the more severe the chlorosis. In some cases, only part of the plant is chlorotic. In addition, chlorotic leaves are more prone to scorching and leaf diseases. With severe chlorosis, the leaf veins will turn yellow, followed by the death of the leaf, the affected branch may die back, and death of the entire plant can occur.