A report on research conducted by Dr. Davis of the University of Massachusetts testing the root hardiness of several Pieris cultivars released to the nursery industry by Oregon State University. The two Pieris cultivars tested were, 'Valley Valentine' and 'Valley Fire'.
To view the article, click on the link attachment.
Aug.-Sept. 1978 Vol. 2, Issue 4 Pages 6-7
R. L. Ticknor North Willamette Experiment Station Oregon State University