THE INTRODUCTION OF NEW HIBISCUS CULTIVARS
The wild form of H. rosa-sinensis is unknown and its origin cannot be traced. The present wide range of cultivars is considered to be a complex of interspecific hybrids between 8 or more different species originating from the African East Coast and islands in the Indian and Pacific Ocean. It is of interest, however, to note that in a hot tropical climate it rarely sets seed and that most breeding-work has been done and is still being done in subtropical areas such as Mauritius, Hawaii, Fiji, India, California and Florida. It is in these areas that many amateur breeders have produced a wide range of cultivars. In the US there is even an American Hibiscus Society which published an Official Nomenclature List as early as 1955. Of course, all these cultivars have been developed for outdoor use and are not necessarily suitable for use as potplants to be raised in plant houses. It is, however, likely that most of the potplant varieties at present in use have simply been imported from tropical or subtropical countries and have been tried out and introduced by commercial growers as potplants without any further breeding.
I believe that a systematic breeding and selection programme to develop specific cultivars for use as potplants is justified because
- the range of colours and types in use as potplants is very limited in comparison with what is known in the garden cultivars;
- it is unlikely that the present cultivars, which were selected for a completely different environment, are the best that can be arrived at in terms of propagation, growth and flowering;
- to assure a continuous demand for a potplant it is important that there is a fairly frequent introduction of novelties.
In Wageningen, at the Institute for Horticultural Plant Breeding, we started a small breeding-programme in 1966 on the basis of a range of cultivars introduced from West Africa, Surinam, Peru, Florida, Indonesia, Australia, Malaysia and commercial sources in Holland and Germany. Many of these introductions proved to be completely sterile and were discarded unless they appeared to have possibilities for direct commercial use. Only a limited number combined desirable characters