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Plant Protection

Select varieties adapted to climatic conditions in your area.  ARS hardiness ratings give an indication of minimum temperatures that a well established plant can be expected to survive without damage.  There is presently no rating for maximum high temperature adaptation.  Hardiness ratings for selected species and hybrids can be found in the ARS website plant database.  The local chapter of the American Rhododendron Society is an excellent source of information on rhododendrons that grow best in your local area. (See chapter locations to get in touch with your closest chapter.)

Even with recommended varieties, plant performance will be improved with reasonable protection from drying winds.  In some northern areas gardeners protect rhododendron plants by building a windbreak around them or covering them with burlap or other protective material during the worst part of the winter.

winter view
Snow coat on R. 'Janet Blair'
Photo by Richard H. Gustafson.
Copyright 1996, ARS.

In the so-called ideal rhododendron areas there may occasionally be damage by early fall or late spring frosts.  In the Pacific Northwest, for instance, there are rhododendrons which will start blooming in February and others which follow along all spring.  These early bloomers may be quite hardy in bud, but the open flowers will be damaged if there is frost.  These plants are usually planted in a protected place and may be covered during a frosty night.

Partial shade is desirable in most cases; in hot dry areas it is essential.  There are a few varieties which simply will not tolerate full sun, developing quite yellowish leaves under such conditions.  There are many others which, in a reasonably favorable climate, make a better shaped plant, and set many more flower buds if grown in full sun.  The beginner, without definite knowledge as to the requirements of a variety, will do well to plant rhododendrons in locations where the plants will receive shade in the afternoon.

  Index of Topics:
  Botanical classifications  |  Use in landscape  |  Plant selection  |  Climate  |
  Protection  |  Soil  |  Planting  |  Subsequent care  |  Fertilizing  |  Pruning  |
  Insect & disease control  |  Propagation  |  Transplanting  |


American Rhododendron Society
Executive Director: P.O. Box 525,  Niagara Falls, NY 14304
Ph: 416-424-1942   Fax: 905-262-1999   E-Mail: lauragrant@arsoffice.org
1998-2014, ARS, All rights reserved.