Question
Some of our Holly plants have leaves which are browning at the tips. Others have leaves that are a lighter green and some are turning yellow with brown spots. What can we do to return the plant to a dark green healthy status?

Answer
Meadowbrook;

Several things can cause these symptoms that you are describing. Most of them are related to an unfavorable root environment. Things like this can include too much or not enough water or possible fertilizer imbalances.  I don't think you are dealing with a disease or insect.  I would suggest having a soil test done on the soil from this area. Contact your local county Extension office or a local garden center or nursery for information about having this done.  It is usually free through Extension. Having a soil test would give you a baseline to start from rather than guessing what you need for the soil.  As always, you could just buy some general fertilizer that contains some minor elements like iron to just try on your shrubs.  Also take a look at the water situation--things like is it too wet in that area or not.  Take a look also at the main stem near the soil line and look for evidence of bark damage.  This is a remote possibility, especially if you have mulch around these plants.

Hope this helps narrow down the possibilities. I can only guess and give you some possibilities without actually seeing the plants.

Steve