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Pruning and Dead-Heading (Withered Flower Removal)

Normally very little pruning is needed.  If a plant grows out over a walk or needs to be restricted for some reason, it may be pruned back moderately without fear that the plant as a whole will be damaged.  It is often possible to do this pruning during the blooming season and have flowers for the house.  Light maintenance pruning at the time "dead-heading" is done (see below), can help keep the plant in shape.  Light to moderate pruning done at the time the plant is flowering or immediately thereafter will not affect flower bud formation for the following year.

Sometimes, as the plant starts to grow, only one growth bud at the end of a stem will begin to expand.  If this single bud is broken out just as it starts to enlarge, it will cause two or more dormant buds at the end of the stem to expand, making a bushier plant.  Again, this will not affect bud set for the coming year.  

Close-up of R. odoriferum bark.
Photo by Eleanor Philp.
Copyright 1996

Old leggy plants may need pruning, but often these are better replaced with smaller newer varieties.  Old plants, however, can be cut back severely and still recover, although it may be a while before they bloom again.

It is desirable, with the large flowered rhododendrons, to remove the withered flower clusters after the blooming season.  This is fairly easily done as the central axis of the cluster, usually called a truss, will break free from the plant with a quick snap of the thumb pushing on the side, or can be cut off with a hand pruner.  With the smaller flowered rhododendrons and azaleas, dead-heading is labor intensive and and generally is not required.

Dead-heading is usually done to make the bush look more attractive, to reduce the prevalence of fungus and to prevent a heavy set of seed.  If it is not possible to remove the old flowers, it is usually not too detrimental, but flowering the next year may be reduced.

  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
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