Xeronema is one of the most remarkable plants in the New Zealand flora, on account of the very obvious appeal of its flowers and its enigmatic distribution. It has become one of the most popular native plants for use in gardens, due to the extraordinary red flowers that it produces in early summer, and its vibrant, sword-like foliage.
Xeronema callistemon is normally associated with the Poor Knights Islands (where it adorns the cliffs and tree canopies), whilst it is also found on the Hen and Chickens Islands. The genus contains only two species; with the other species, Xeronema moorei, occurring in New Caledonia, where it occupies rocky mountain sites.
The discovery of Xeronema is an interesting tale. W. M. Fraser, a naturalist and Maori scholar “discovered” it on the Poor Knights Islands. However, it was not entirely coincidental that he came across the species; he had been asked by the eminent New Zealand ethnographer, Elsdon Best to seek on the Poor Knights Islands a plant of Maori tradition, called raupo taranga.
After some botanical study, the plant was determined as belonging to a genus that had previously comprised just one species (X. moorei); that species growing in the inland mountains of New Caledonia. It was a truly remarkable addition to the New Zealand flora, due to the connection with New Caledonia and its large, brightly coloured inflorescences. The specific name of callistemon (which is Greek for “beautiful stamens”) refers to the resemblance of the inflorescence to that of the Australian bottlebrush (Callistemon spp.).
Xeronema has become particularly popular in recent times with the rising popularity of sub-tropical gardens in Auckland. The widespread use of the plant belies its actual capacity for use in gardens. It is a common sight to see Xeronema plants rotted back to the base, as the result of being planted under normal garden conditions. This is not a plant for the average urban garden soil, for it inhabits the cliffs of rugged, sub-tropical islands.
Therefore, it requires conditions similar to those under which it grows in the wild. Very good drainage is essential, and plants benefit from root restriction. They also benefit from the application of salt water (once yearly) and seaweed, as indicated by its extreme coastal habitat. The satisfaction of these conditions will encourage the plant to flower earlier than it normally would. One must usually wait 5 to 6 years to get flowers off a Xeronema, but I have heard of cases of plants flowering surprisingly precociously.
Due to its affinity for the aforementioned conditions, Xeronema makes an ideal pot plant. It is also especially suited to being attached to the forks of trees (in which position it often grows on the Poor Knights Islands), and on crib walls (an application that we have seen at Hortresearch’s grounds in Mt Albert, Auckland – shown above).