Available from - High Country Roses
highcountryroses.com

My experience with 'Wilhelm' has been the exact opposite of the previous poster. My garden is in central NC- fairly mild winters, wet springs, hot and humid summers. My specimen has proven extremely vigorous, healthy, free-flowering, heat-tolerant and shows very little susceptibilty to fungal issues. I highly recommend this rose.

This rose mildewed like crazy here in Georgia. Never saw anything like it. Early spring, while everyone else is happy, this rose nearly dies of mildew.