Question
We have a new varigated holly bush but it's leaves are turning redish yellow what is wrong with it ?

Answer
Dear David, I am assuming that you are talking about already established leaves on the plant turning color.  It is common for new leaves to start off sometimes with a very reddish color.  After the leaves are mature, however, the color change would usually indicate a disease.  Probably the reddish yellow color is in the form of blotches, in which case, you likely have a fungal leaf spot, probably Cercospora or something similar.  The best treatment for these stubborn fungal infections would be a strong fungicide containing the active ingredient Proprioconozole or Chlorothalonil.  Either of these is excellent for treating fungal diseases.  In addition, you will need to (while wearing gloves) clean the entire area of fallen leaves.  These fungi are often spread by the disease on fallen leaves which, when watered, will splash up and re-infect the plant.  Also, avoid watering at night time when the cooler temperatures will encourage fungus growth.  So, clean up the area, water only in the morning or mid-day, and spray with fungicide.  If your leaves don't fit this general description, or if your country doesn't have these ingredients in fungicides, let me know what you have available or how your leaves differ and I will update my answer.  I hope this information is helpful.  Good luck, Melissa