Photos by Linda Langelo, CSU Horticulture Program Associate
The condition in the above pictures is an iron deficiency. Along with the iron a leaf scorch is sure to follow. There are many reasons for an iron deficiency among which is compacted soil, soil that is too wet or too dry. If the pH of the soil where the tree is planted ranges above 7.0 into 7.2 and 7.5, then this condition begins. Take a soil test before you decide which type of tree you can plant in your landscape. Along with crabapples, maple trees are also very susceptible to iron deficiency. Without adequate iron, the tree cannot complete the photosynthesis cycle. So the tree ends up not getting a good supply of sugars and starches. Applying chelated iron is helpful.