A few weeks ago, before the weather turned quite so wet, I clambered up Taratahi Mount Holdsworth.
I knew it was too late in the year to see the many wildflowers that are such an attraction above the bush line, but I was pleasantly surprised by how many plants were carrying berries. On the lower slopes it was almost exclusively various species of Coprosma, some of which I could identify, but some were new to me. The berries ranged from bright orange through softer tones, to some lovely light blue ones.
However, the most exciting plant was up much higher on the maunga, in the area sometimes called the goblin forest, where the trees are reduced in size, and the undergrowth is sparse. Growing and glowing in the dappled shade, and in full berry, was a bright mountain astelia, probably A. nervosa.
This plant had the silvery-green leaves that one might associate with North Island versions and was carrying a large crop of bright orange berries. It was the only berry-carrying astelia that I saw on my trip.
Astelias are slowly becoming popular in New Zealand gardens, especially for those looking for some textural contrast – they look great when grown in association with large-leaved plants like rangiora, or alongside grasses and sedges. In the wild they are largely epiphytes, growing high in the branches of large trees, earning them the common name of perching lilies, but most species will adapt to growing in the ground. Superficially, their rosette growth habits and fibre-rich leaves bring to mind New Zealand flax plants, and they can be used in similar ways in the garden.
There are several forms of A. nervosa available in the garden trade, the silvery green one being perhaps the most popular. It is usually grown for its foliage with nice arching leaves and carries spikes of subtly coloured very small flowers in the summer. In the South Island, this species tends to have deeper coloured leaves, and nursery owners have been keen to selects stronger-toned cultivars for the horticultural trade. One of the best of these is ‘Westland’, which has arching foliage of red/brown, colouring that intensifies with colder weather. Like most cultivars of this species, it will do best in semi-shade, and looks very impressive when planted in bulk. It grows to about 80cm.
The most popular of all the astelias is the large form from the Chatham Islands called – wait for it – Astelia chathamica. This is a true beauty, with large clumps of metallic silver leaves growing to about 1.5m and looking like an improved flax, with more textured leaves. This likes very good drainage, so do not plant it in a wet spot, but otherwise is easily grown and quickly provides an interesting focal point. It also flourishes very well in containers.
‘Frosted Bronze’ is another of the Chatham Island varieties worth planting. It is also a taller variety, growing to about 1.5m, but in this case, the new foliage appears with a rich purple-red colouring that fades to silvery-bronze. Like ‘Westland’, it takes on deeper tones over winter.
The trend for more natural-looking gardens has seen an increased uptake in the use of New Zealand’s own natives, but the range of plants used is not usually very large – lots of hebes, sedges, dwarf pittosporums, coprosmas and small flaxes. However, some really interesting natives should find their place in the garden.
For many years we had a wild Spaniard in our front garden – no, not an irascible European, but rather a speargrass, taramea, Aciphylla squarossa. This lovely rosette-forming plant has very sharply pointed leaves, hence the “wild” and “speargrass” part of the common name. It grows wild in Wairarapa, in sub-alpine areas but also occasionally in coastal areas – there are some lovely plants growing wild at Matakitaki-a-Kupe, Cape Palliser. There it almost looks like tussock, but in summer it pops up flower stems, with lots of small flowers, and some interesting spikes too. It needs to be planted in moist but well-drained soils and prefers sun or semi-shade. Our plant was eventually overgrown by a large evergreen magnolia and died out. I have to say that weeding around it was a nightmare – those pointed leaves got even sharper when they died off around the base of the plant – so I didn’t miss that part of the job.
The renga renga lilies are more suited for a shady spot, with their lush grey-green leaves and masses of pretty white flowers. There are several selected forms available, including ‘Matapouri Bay’ and ‘Parnell’, both with growth to about 60cm, while ‘Te Puna’ is a smaller growing form. All will need protection from the worst of our frosts and do best in well-drained fertile soil in at least semi-shade. Apart from that they are easy to grow.