My Pieris that was planted in June, 2008, has half of it's leaves turning brown and all of the flowers are brown and dead. A second plant (planted same day), located across sidewalk, 8-feet away is brilliant green and hundreds of white, hanging flowers. What could be wrong with the one Pieris???
Since it is part of the shrub rather than the whole thing, as might happen if soil ball had dried out probably root rot caused by water molds such as Phytophthora. New to North American forestry and horticulture is P. ramorum. This may attack the foliage directly and produce a blighting off like you have described, rather than damaging roots and causing dieback from below. Try your state Cooperative Extension Service for assistance with identifying possible causes of garden plant problems likely to be pathogenic. In addition to finding out from them exactly what you are dealing with and what can be done about it, if P. ramorum has appeared on your site they may like to know about it being present in the area.
