Cowichan Valley Rhododendron Society
Newsletter
Volume 37:8
Hoar Frost on a Rhododendron
Editor: Verna Buhler
Contributors: Alan Campbell, Dorothy Kennedy, Verna Buhler, Debra Lamb
Technical Support: Joanne Meredith
Table of Contents
November Brings Frost
As November settles over the Cowichan Valley, the season's first frosts typically arrive on clear, calm nights when temperatures dip toward zero. While our Vancouver Island climate is milder than the Interior's, low-lying areas and frost pockets near the Cowichan and Koksilah rivers can see frost weeks before more sheltered properties. Most rhododendrons hardy in our region tolerate light frost well — the gentle onset of cold here is one reason the Valley suits them so beautifully.
A little preparation makes all the difference. Ensure plants enter winter well-watered, as moist soil insulates roots better than dry ground, and apply mulch around the base while keeping it slightly back from the stem. Avoid fertilizing now — tender late growth is vulnerable to frost damage. Newly planted or marginally hardy varieties benefit from a burlap screen or temporary cover on the coldest nights, removed during the day so air circulates. And in spring, wait until new growth appears before pruning out any browned, frost-damaged foliage. Members are always welcome to share winter-protection tips at our monthly meetings.