Inkberry Holly with something powdery on leaves?

Question

What could this be? It has a grayish-white powder on all of the leaves that can be rubbed off. It is definitely nothing I have sprayed on or near it. Is it a fungus?

Answer 1

It's probably powery mildew
Holly disease factsheets
http://plantclinic.cornell.edu/treeshrub/holly.htm
The Plant Disease Diagnostic Clinic at Cornell University is located at 334 Plant Science Building, Ithaca, NY,
http://plantclinic.cornell.edu/FactSheets/powdery/powdery.htm

Ortho® Garden Disease Control
http://www.ortho.com/index.cfm/event/ProductGuide.product/documentId/031ae09d4fc805010313841419e1c54d
Stops and prevents over 130 diseases including rust, leaf spots, blights, powdery mildew, fruit rots and more (see label)
For use on vegetables, fruits, roses, flowers, shrubs and trees
Ortho makes a product called SEVIN DUST it come in 5% and 10% strengths most garden centers carry 5% it's a whole lot less toxic, and can be used on dog for fleas. It also treats powerdy mildew.

Answer 2

It is called powdery mildew, and it is a fungi, occuring in moist climates, or from over the top watering, usually forming underneath the leaf first. Usually a liquid soap solution mixed with water, sprayed all over the plant will do the trick. If not, a heavier duty fungicide, or even baking soda mixed with Sun Oil will work.