Question
I live in central Oklahoma, started my corkscrew willow tree from a cutting.  The tree did really well for the first 3 years, now the leaves are a pale green (not yellow) color, otherwise the tree looks healthy.  I am concerned because the leaves are such a pale green, I wonder if there is some kind of nutrients that it might need.  I fertilized the last 2 years with tree spikes.  I have another smaller corkscrew willow that has beautiful lime green colored leaves, looks fine.  Any clue as to what this tree could need?  It is getting big, probably 12-14 feet and I don't want to lose this tree. Have asked some of the greenhouses in my area and they don't seem to have a clue.  Thanks for your help!

Answer
I would fertilize it with a whole fertilizer such as 13-13-13. Spread the fertilizer under the tree but not within 6 inches of the trunk and water in. I would put about a Lb. out each month until it looks better. I would also add some Iron to the mixture here is a web link for the use of iron to green up Chlorotic trees:
http://www.oznet.ksu.edu/library/forst2/mf718.pdf