Question
The leaves on my Crimson King have turned to a milky white color? Any idea of a cause and/or a treatment for this?

Answer
Sounds like a disease called powdery mildew. The damage due to infection by the fungi causing powdery mildew can be slight to severe. The disease generally occurs during spring, fall and winter months during cool weather with high relative humidity and in shady areas.

A powdery, fluffy white to light gray-colored fungus growth on succulent stems, leaves, buds and flowers is the characteristic symptom of powdery mildew. Young plants and actively growing shoots are more severely damaged than older plants, leaves or branches. Infected leaves may be dwarfed, curled or deformed. Powdery mildew can destroy the blossoms on crape myrtle. Small dead flecks in the leaves and defoliation may occur on some varieties of azalea and rhododendron that are infected with powdery mildew without the obvious development of white fungus growth.

Spray the foliage and branches with a fungicide. here is a list of fungicides to use on powdery mildew.

Propiconazole (Banner Maxx) is registered for control of powdery mildew and numerous other diseases on ornamentals.

Myclobutanil (Systhane, Eagle, and Immunox) is registered for control of powdery mildew and numerous other diseases on ornamentals.

Sulfur as a spray or dust as needed. Sulfur may cause some plant injury if applied when air temperature exceeds 90 F.

Triforine (Funginex) is labeled for use on roses and several other ornamentals. Follow manufacturer's instructions on the label. This product is only available in small packages.

Triadimefon (Bayleton and Strike) is now registered for use on a number of ornamentals.

Fenarimol (Rubigan) is a locally systemic fungicide for the prevention or therapeutic control of powdery mildew of field or landscape grown ornamentals.

In some situations copper fungicides will provide control of powdery mildew.

Check with your local nursery/garden type store for one of these. Make sure next spring you spray the new foliage --this will kill any spores that may have made it through the winter months. I would also rack up the fallen leaves and move them off the site so the spores will not reinfect the leaves.