by Dick Beamish
Rhododendron Rubicon was hybridized in New Zealand by Ron C. Gordon and registered in 1979 as RHS 79. It seems that it arrived in North America in 1980. It is a cross between Noyo Chief and Kilimanjaro and superior to either of its parents. Kilimanjaro is an Elliottii cross that is red, has chocolate spots on the dorsal lobes of the 18 or so flowers that bloom about mid-season. Kilimanjaro has a cold hardy rating of – 15 °C. Noyo Chief is an Arboreum ssp Nilagiricum cross that also is red, blooms early-midseason and has very glossy slightly bullate leaves with darker veins and a cold hardy rating of –12 °C. The cross of Noyo Chief and Kilimanjaro took the best features of each parent and made them better.
Rubicon is a very common and a popular rhododendron in New Zealand that has been described as the best New Zealand rhododendron of all time. There is even one article that rates Rubicon as the best dwarf rhododendron in the world. Greer describes it as a “superior” plant. This is a compact plant that is wider than tall and rated as 1.3 m after 10 years. The medium sized leaves are a glossy deep green with even darker, prominent veins. The size, shape, colour and arrangement of the leaves are perfect. The flower is described is cardinal red, but it is a darker cardinal red and probably could be best described as “Rubicon red”.
All of this is perfect, but it is the bloom time that contributes to making this the world’s best hybrid. In our garden we have 5 plants than are in partial sun to full shade. They are one of the first to bloom and one of the last to bloom. Even one plant will bloom over a two month period. The truss has too many flowers to count, but it is described as having 17 to 18 flowers per truss which is perfectly shaped with black spotting on the upper lobes of the flower and distinct white anthers that contrast the dark red flowers.
A blooming Rubicon immediately stands out in any garden because of the unique red but also because almost all the trusses are compact and perfectly symmetrical. A good truss always wins a ribbon in a show and will occasionally satisfy a judge as the best in the show. It has a reputation around the Vancouver Island as not being hardy, but it is listed as hardy
to – 15 °C which is colder than I recall it being for winters around Nanaimo. Paul Wurz lives outside of Campbell River and has 2 he keeps in pots which is one way of enjoying the plant and protecting it if there is an exceptional cooling event. Certainly Rubicon is well worth any additional effort.