Autumn Blaze Maple with chlorosis

Asked June 8, 2014, 7:59 PM EDT

We have an autumn blaze maple about 18 years old that appears to have chlorosis. Leaves are getting smaller each year and more yellow. We have tried deep root feeding with chelated iron for 2 years but it doesn't appear to be helping. Someone said we should test our soil pH and also analyze our water. They did not recommend the iron plugs that go into the tree trunk.
1. Should we analyze our soil and water?
2. If so, how deep do we dig to get a soil sample?
3. Where do we send samples for analysis?
4. We try to deep root feed at the drip line of the tree but are limited due to patios, fences, etc. Where is the best location around the tree to deep root feed?
5. For chlorosis, would you recommend the iron plugs that are inserted into the tree trunk or will this cause more damage?
Thank you for your help.

Boulder County Colorado trees and shrubs

1 Response

Unfortunately, maples often suffer from iron chlorosis in Colorado soils. Some interventions can help minor problems however some treatments can be costly over time and have limited results. Chlorosis can be caused by a variety of issues and I suggest further reading from the following document. http://www.ext.colostate.edu/mg/Gardennotes/223.html.

Soil testing would determine the ph level which would help to determine if treatments for lowering ph would be beneficial. Here is a link to information specific to soil tests http://www.ext.colostate.edu/mg/Gardennotes/221.html.

Water testing would not be helpful unless you are on well water.

Chlorosis can also be caused or magnified by over watering and over fertilizing. Please read the following for more information on fertilizing http://www.ext.colostate.edu/mg/Gardennotes/223.html and read the direction specific to the fertilizer you are using.

Finally, we neither recommend or don't recommend iron plugs but would suggest that you confer with a certified arborhist who could help consider the multiply factors in determining a treatment plan.