Nick Hansa of Fairhill Native Plants describes their new Grafting Grevilleas onto Silky Oak root stock as a fantastic point of difference that has enabled many types that simply wouldn’t grow in Queensland soil to thrive. Grafting grevilleas is, of course, hardly a new concept as they have been grafted for many years in order to bring plants from other niches that struggle to grow in eastern Australian soil with their own root system.
What Nick and his team at Fairhill are doing differently is grafting what will grow here in Australia but have a tendency to fail if not grown in their preferred conditions. It provides those with heavier soils the chance to successfully grow this genus of plant. The robust root system of the silky oak grevillea also makes the plants far more tolerant of the vagaries of the Australian weather (prolonged wet and prolonged dry periods) which it seems have been very prevalent these past few years.
The native Grevillea is generally grown successfully all over Australia, but Grevillea robusta, commonly called ‘silky oak’ also has the advantage of being a fantastically adaptable member of the Grevillea family. Its natural home is found within the rainforests of the sub tropics and often around water. Its adaption to the cooler conditions of Australia’s southern states has extended its list of qualities. Unusually for the tree that started in the wet climate of the rainforest tree, it has considerable drought tolerant properties and equally surprising is its cold tolerance.
So why is grafting the answer, in blending proven properties in two plants in this case? Nick Hansa explained, “Grafting is an excellent option because it allows the plants to establish comfortably on a rootstock that is compatible with the local climate and soil”.
There is such a wide variety of colours and foliage forms in the Grevillea genus. These Australian natives can be combined to produce a beautiful array of colour and result in stunning gardens and landscape projects. The many advantages that grevilleas have is that several groups form excellent ground covers and hence make a superb weed suppressant. Combining that with their lack of desire for frequent feeding, it sends them very nicely down to the low maintenance group of gems we can rely on.
The impact these natives have is not only visual but practical too. Grevillea flowers attract many species of birds to the garden. They are an excellent producer of nectar for bees and food for possums.
So what started the ‘Grafted Tough’ range? Nick explained it was a chance find situation from the misfortunes of the 2010 floods. “At Fairhill, the retail staff had a customer from Brisbane wanting to have grevilleas in his garden. His garden is fairly flat and clay soil so they were pretty insistent that he only use grevilleas grafted onto silky oak. Unfortunately for him, but probably fortunately for us, his house was flooded in 2010 and under water for four days. All of his grevilleas survived”.
So what was the key to the flooded gardens survival rate and findings? Nick explains that they are not called ‘robusta’ for nothing, “Silky oaks have stronger, deeper roots that are resistant to phytophthora. Almost all other grevilleas have very fine shallow roots. The main reason that grevilleas die in wet conditions is that their roots are attacked by phytophthora. Silky oak will tolerate waterlogged soil for weeks, this is probably why our customers plants handled the flooding”.
Nick explained that water saturation was not their exclusive quality, “General fertilisers can be used without the fear of phosphate toxicity. Most forms are bushier when grafted, our experience is that they require less pruning. Over all the plants are stronger, much more tolerant of adverse weather conditions and potentially, a longer lived plant”.
Trialling continues in full swing at the nursery and many of the varieties can be seen at their botanic gardens in Nindery. Nick hopes that the ability of the grafted types to be grown better in containers will add further to their appeal for both the retail and wholesale industry adding, “Many grown on their own roots don’t take to containers. I believe our ‘grafted tough’ range in the extremes of our current climate, has given them all a better chance of survival”. Music to the ears of native lovers up and down the land.