Yellow tips that then turn brown are the first sign that a plant or tree has been over fertilized. If you really over did it the outer edge of the leaves tend to be affected next.

I am wondering if it could be something else like the cold. I have a Limequat that was planted last Spring and it has never been fertilized and is planted in native soil that has the same thing going on. As does a Dwarf Lemon tree that is older. None of the other citrus in the area have this issue and the only difference is that the two effected trees were not covered during the freezes and the others were.

Well, this tree has easily survived in-ground for 25 years. We actually had never fertilized it before two weeks ago. The yellow tips started appearing a couple of months ago and appear throughout the tree - outside leaves and internal leaves.

I'm guessing its just a response to the cold soil temperatures we had this winter. When soils are cool, plants (especially citrus) have a hard time pulling nutrients out of the soil. When the weather warms up the symptoms usually dissapear.

This is one reason why it isn't beneficial to fertilize in the winter - plant roots are pretty inactive at this time of year and can't process the nutrients.

As long as you followed the recommended amounts when applying your fertilizer your tree should be fine. In case you need more information on fertilizing, use the U of A publication located at the link below.

A guide to common nutrient deficiencies and herbicide damage can be found at http://cals.arizona.edu/pubs/crops/az1007/contents.html

Here is a link that might be useful: Fertilizing citrus

goldiell if it was not a sever over fertilization then the damage is done and it will get better. If it looks like its getting worse by spreading to the leaf edges then you over fertilized by a lot. If thats the case then lots of deep watering in is order.