G94-1218 Iron Chlorosis of Trees and Shrubs
© 1994, The Board of Regents of the University of Nebraska on behalf of the University of Nebraska–Lincoln Extension. All rights reserved.
This NebGuide describes the symptoms and causes of iron chlorosis in trees, shrubs and other ornamentals, and provides three techniques for correcting it.
Many trees, shrubs, and other ornamental plantings in Nebraska suffer from iron deficiency induced by poorly drained or compacted soils or by soils with a high calcium content. These soils are characterized by pH levels above 7.5. The unavailability or non-utilization of iron commonly causes a condition called 'chlorosis,' an abiotic disease characterized by yellow leaves, slow growth, and branch dieback. In eastern Nebraska, pin oak and silver maple frequently show this condition. Chlorosis becomes progressively more apparent on many other kinds of trees and shrubs as one travels west across the state. This is due to increasing soil pH levels.