Words & Photos: Dylan Norfield
Whether it be to admire design, plant combinations or true wow factor, visiting other people’s gardens is a pastime all gardeners love. For many of us, the greatest excitement comes from spotting plants less familiar to us. The more you learn about plants, the more you realise what you don’t know and how many species there are out there that we can grow in our gardens. In New Zealand there are an estimated 25,000 to 35,000 exotic plant species, along with 2000 native species; we have a huge range from which to choose.
Around the world, pressure on many plant species is increasing. This is largely due to human interactions with our environment, be it from direct deforestation and population pressures or indirectly through climate fluctuations. A report from Kew recently on the ‘state of the world’s plants’ put the number of the world’s plant species at risk of extinction at more than 20%. This is alarming, but we can all do our bit by growing the rare and unusual in our gardens, securing many plant species in captivity.
Our native plants are listed under the New Zealand threat classification system, which aims to rank all our natives from ‘not threatened’ to – the most serious – ‘nationally critical’. The twining vine Tecomanthe speciosa is classed as threatened, nationally critical, but has become a success story. One plant existed in the wild on the Great Island, of the three Kings Islands. It is still at serious risk in the wild, even with intensive management of potential pests, but due to its natural beauty and suitability as a great garden plant it is sold widely around the country for its aesthetic properties.
A very similar success story is of Clianthus puniceus, also classed as threatened, nationally critical, and better known as the kakabeak. Again, it is only known from one plant in the wild, but the attractive red, pea-like flowers have made it a garden favourite not just in New Zealand but around the world.
The lesser-known Gunnera hamiltonii may not be in the same league as the previous two, but still has its own beauty, despite its smaller stature. It is a sand dune plant only found on the south coast of the South Island, near Invercargill and Stewart Island. It makes a beautiful ground cover being easy to grow and available from many specialist native nurseries. Its biggest problem is that the remaining populations are scattered, with most only made up of one sex. This is making it difficult for seed to be produced and has been classed as threatened, nationally critical.
Other plants the world over have similar threats, especially due to human population pressures. Acer pentaphyllum from southwest Sichuan in China is a very rare species that has suffered due to subsistence farming in the area where it naturally grows. Unfortunately, even though it is protected by the government, trees are still being harvested by locals for firewood with estimated numbers now at less than 200. Franklinia alatamaha is so rare it is now extinct in the wild and only known in cultivation. The beautiful camellia white flowers are borne in autumn against the red and orange autumn colours.
Closer to home, one of the success stories of recent years was the discovery of Wollemia nobilis. The so called Wollemi pine was discovered in 1994 only 150km north-west of Sydney. Previously known only from fossil records, it is in the same family as the better-known monkey puzzle tree.
The biggest problem is sourcing all these amazing plant species, as the range in many garden centres is decreasing due to many nurseries over the past decade closing down. Do not despair, however, as the plant material is still here, but often you will need to join local clubs and plant groups to find the unusual, and acquire the material through the generosity of gardeners. The few remaining specialist nurseries also need our support, so by asking for the unusual at garden centres and nurseries we can support the industry by keeping the wide range that we can grow available.