Asked January 21, 2020, 3:20 PM EST
My silver maple is showing a lack of nitrogen and probably other nutrients. What is the best form of fertilizer, what method of application and what is the best time of year to do it? The tree is approximately 50+ years old. It is not in the lawn and gets watered regularly, the soil is not over watered. We are located in Centennial and the soil is sandy.
Arapahoe County Colorado
Thanks for using Ask an Expert for your home gardening needs. It sounds like your tree is possibly suffering from iron chlorosis. There is plenty of iron in most Colorado soils but it is in an unavailable form in some cases. The online Garden Notes sheet #223 has information to answer all of your questions. You can access the Garden Notes at www.cmg.colostate.edu