Nikau: stalwart of the south

At this time of year it is easy to think of places in the sun, places we like to escape to. The quintessential plant of the tropics is the palm tree. The most important of these is the coconut palm, a true icon and it is not found outside the tropics. Its slender trunks and swaying fronds line most sandy beaches in the islands. But it’s not an altogether innocent tree because its falling nuts can injure people who seek their shade. In our climate, though, there are many palms which are well suited to evoke the tropical escape. Not least of all, the native nikau, Rhopalostylis sapida. Even within the range of the New Zealand geography there is quite some variety in its form. On the Chathams, the nikau has rather more stout trunks and a robust crown shaft. This population, which is now confined only to Pitt Island, consists of only 70 specimen and is under threat. It is also the most southerly occurring species of palm in the world. Further to the north is a population on Little Barrier Island where the variant is larger in all proportions than those of the mainland populations. Here the trunks may grow up to half a metre in diameter! Intermediate between the Little Barrier Island palms and the mainland group are those of Great Barrier Island. Further still to the north, on the Kermadecs, is another nikau. This one however has been put into a separate botanical group, Rhopalostylis baueri var. cheesemanii. syn. R. cheesemanii, R. baueri var. kermadecensis. So now with its botanical identity established it can be described as a more robust species than the New Zealand nikau, with a larger crown shaft of fronds of a more arching nature and largely more tolerant of wind. In my observation the New Zealand mainland species of nikau R. sapida, found flourishing in the bottom of gullies, is less well adapted to the environment above the canopy of the forest. Once exposed to the elements the fronds tend to burn and look a little tatty. For our purposes, the old saying ‘right plant in the right place’ must be observed. There is yet another member of this genus, from Norfolk Island, the Norfolk nikau, R. baueri var. baueri, which I have never seen it advertised for sale.

Now is a perfectly good time to be planting palms as long as they are given plenty of mulch and not fed until they commence into their summer growth. While the palms are dormant it is inadvisable to feed them as the roots are easily damaged at this point. Once new fronds start to unfurl is a good time to be feeding, the plant is growing and will take up and use the nutrients supplied. Nikaus especially will benefit from timely feeding, increasing their rate of growth substantially. In the wild nikaus are notably slow to form a trunk, taking up to thirty years before it begins to emerge!

While on the topic of sunshine, I have in a pot on the deck some Cape cowslip Lachenalia aloides ‘Aurea’. These bulbs from South Africa, as the common name suggests, are an old fashioned favourite. Whose grandmother didn’t have a row of them at the front of their garden bed? Well mine were given to me by a friend, not my grandmother, but each year they multiply and intrigue me from the first emergence of the green and red mottled leaves in autumn to the striking yellow and red flowers during the dark days of winter. Thank you, Greg, for this gift I always enjoy them, a splash of sunshine during rainy days.