Question
We have large borders of Holly bushes, about 5 years old.
This winter, although unseasonably mild, we lost 5 large bushes.
It appears several other bushes are also stressed, emerging
flowering foliage is brownish/black and dying.
The leaves seem to be healthy and green, only the tips are
withered.
Any information would be greatly appreciated.
Thank you for your help.

Answer
Dear Catherine, The appearance of black foliage suggests that you have scale on your holly.  Scale is an unmoving insect in its adult stage, and the insect is protected under a shell or scale, which may be white, brown, or black depending on the type of scale.  Scale also secretes a honeydew which accounts for the blackened sooty foliage.  If you look closely, you will notice small bumps on the plants, on the leaves and stems.  Scale doesn't respond to most insecticides because the hard covering protects it from most chemicals.  To get rid of them, you will need to spray with a horticultural oil product.  The oil will smother the insects, and cause them to fall off and die.  SunSpray is one of the best.  Do not use cooking oil.  You will need to spray several times about a week apart.  You will know that the oil is working when a moderate stream of water knocks the scale loose from the plant.  If the plants are heavily infested, it may take a while to clear them up, but this method will work.  I hope this information helps.  Write back if you have more questions.  Good luck, Melissa