ise Corymbia ficifolia, the red flowering gum from around Albany in south-west Western Australia with the swamp bloodwood, Corymbia ptychocarpa from northern Australia, which has the same spectacular terminal flowers common to all the Corymbias, but is obviously much better equipped to cope with the humidity and heat of northern Australia. By crossing those two species together, we get a group of hybrids which has been marketed as the Summer series – ‘Summer Red’, ‘Summer Beauty’ and ‘Summer Snow’, a white variety. By and large it’s been quite a successful series when planted in gardens up and down the east coast, from Melbourne through to Queensland. Hybridisation is one way to go, and I like to think of what he’s done as a wonderful reconciliation, a sort of ‘east meets west’, between the swamp bloodwood from the east and north east and, from the other corner of the continent right down in the south-west, the red flowering gum. That’s where I think plant breeding really does have a place in modern horticulture; to combine the outstanding features of two different species to come up with a plant that has all the right attributes to be a successful garden plant.
One of the issues with all the selections, whether they’re straight selections of Corymbia ficifolia or hybrids like the Summer series, is that they are difficult to propagate by cuttings – too difficult for commercial production. The way that they’re propagated now is by grafting onto the rootstock of a hardy member of the Corymbia group, such as the spotted gum, Corymbia maculata, or the red bloodwood, Corymbia gummifera. Finding the right species to use as a rootstock for different areas has become one of the key challenges for the selection and improvement of the Corymbia group, and in particular the flowering gums.
The second wave of improvement of the red flowering gum has come about through the selection of different clones of the red flowering gum though the hundred years or so that this plant has been in cultivation. In southern Australia, from P