JARS v37n1 - Hybrids or Species

Hybrids or Species
Herbert A. Spady, M.D., Salem, OR

Reprinted from Portland Chapter Newsletter

Among rhododendron enthusiasts there exists some friendly conflict between hybrid growers and species purists. Even though the arguments range, one seldom sees a rhodoholic's garden without some of both.
The very reason for hybridization is to improve the parents in some way. Do hybrids do that? Indeed they do. Rhododendron species have certain glaring deficiencies for the usual gardener. On the whole they are tolerant of only a very narrow range of growing conditions. A few species have tolerance to cold, heat, less acid soil, and other adverse conditions. Many gardeners would like plants that do have those tolerances. When these or other desirable characteristics exist they usually do so at the exclusion of the perfect flower or plant habit. Hybridizers have been working over the years to combine these various characteristics to yield hybrids that are suitable for a multitude of garden and landscaping conditions. They are not finished yet. Dramatic improvement can be expected over the next few decades. One bonus of hybridization is often hybrid vigor. This frequently results in plants that are "better doers" than any of the species parents. Many hybrids are easy to propagate and are readily available in the nursery trade. Many hybrids bloom at an earlier age than either parent and with more abandon. They may exhibit sharp contrast to species plants that may be seen struggling to survive the heat, cold, fertilizer, or other less than ideal conditions in most collections.
With all that praise and virtue why grow species? Why climb a mountain? Because it is there? Strong motivation will come to many gardeners just because these are interesting plants encompassing a vast array of different types that grow around the world. Shall we say that species plants are more interesting than hybrids because they come from "Nature's Garden"?
Some species enthusiasts take strong pride in their collections and the avoidance of hybrids. Be that as it may. To the real student of the genus (hybrids and species) the species are the basis for an understanding of the hybrids. Without some experience with and knowledge of species one can not understand the principle and results of hybridization.
Finally, there is something lacking in hybrid rhododendrons. The void is usually in the plant habit and leaf, but occasionally in the flower. Probably the void is seldom seen in the flower because the hybrid is usually selected for its flower. One seldom sees the soft felt green in the leaves of any R. griersonianum hybrids. Although used to reduce the size of larger species or hybrids, its offspring seldom capture the balance of plant size and leaf size seen in R. williamsianum . No doubt many of these fine characteristics of the species will be captured in the hybrids someday, but if you want them today you must grow species. "The appeal of the species is great, but as with other entertainments of refinement, it plays to a small audience."