Sunday, November 22, 2009
This weird spring has had many gardeners scratching their heads, wondering quite what the climate gods are going to throw at us next. Most of us have planted our summer vegetables, but every week or so another southerly comes through and we look out our windows at night, worried that the morning might see a frost.
So where is the weather headed for summer?
It looks suspiciously like the meteorologists are ducking for cover on this making statements about possibly slightly warmer or perhaps slightly cooler weather, and maybe above, maybe below average temperatures.
But Maori lore is telling us we are in for a hot, dry summer. There is a long-held belief that a better than usual flowering season among ti kouka, cabbage trees, indicates the following summer will be warmer and drier than usual. Looks like we are in for a warm one based on the exceptional flowering of cabbage trees this spring.
The strong stems of these giants of the lily world are a strong feature of the New Zealand landscape, and many New Zealand artists have drawn on their strong outline to portray the New Zealand landscape.
Maori harvested ti kouka, eating the new leaves, and preserving the roots in a complicated process, to extract the sugars. Early pakeha settlers are also said to have eaten the hearts of young trees, giving the plant its common name.
Our relationship with the cabbage tree in the garden is a little more complex. Although very valued in the larger landscape – both in the wild, and in parks and commercial plantings – we are more reluctant to bring the ti kouka into the garden.
I am sure this is partially due to the problem of the fallen leaves. Mature trees tend to drop lots of leaves in the late spring period, at about the same time as our lawns grow with the most vigour. Cabbage tree leaves have very strong fibres – Maori used them to make fabric - and they will win a battle with lawn mower blades. This has meant many gardeners – especially those whose job roster includes lawn mowing – are very reluctant to have cabbage trees around.
There are two steps to take. The first is to ensure the trees are planted in gardens rather than as specimen trees in the lawn, where the leaves will prove a problem. The other is to gather the leaves and keep them until they are completely dry. Under these conditions they make superb kindling.
There are a few species of cabbage trees for the garden, and a few cultivars as well.
The most common species is Cordyline australis, with long green sword shaped leaves. This is the wild form most commonly seen in the wild and it is easily grown as long as a little care is taken at the time of planting. It will flourish best in well cultivated soil, and establishes most quickly if given a good head start with adequate watering.
The toi, C. indivisa, is a beautiful tree with broader leaves, often with a purplish cast and an orange midrib, and heads of the most amazingly scented flowers. It grows naturally in the mountain forests of our regions, and is a always a delight to stumble across when in on a tramp. Unfortunately this charming species is not easy to bring into the garden. It seems to need the higher rainfall and moister atmosphere of the mountains.
C. banksii is another forest species, with shorter stems and longer leaves. There is a nice purple form of this species that is sometimes available from specialist nurseries. It is another species that does best in cool and moist conditions.