Yellow leaves? Iron chlorosis symptoms and treatment.

My hydrangeas have been yellowing for a couple of years. Up until now I‘ve treated them with an iron supplement. Note – Yellow leaves are a very different issue than ASTER YELLOWS.

After doing some research, I’m ready to work on some probable causes:

– lower the pH

– correct a drainage problem

– As always, I should be doing a soil test before doing anything else!

Here are three excellent articles on identifying and dealing with chlorosis:

Missouri Botanical Garden – Iron Chlorosis

Utah State University – what is Iron Chlorosis and What Causes it?

Government of Canada Agriculture – Iron Chlorosis