Tuateawa Plant Spot: Kowhai.

The year is moving along. Townies can tell, by what appears in the shops! Xmas decorations are now available! In shopless Tuateawa spring is on the way because the kowhais are in bloom. It is always worth taking some time to sit in a kowhai grove and watch all the activity. Tuis alternate between feeding and aerial combat. If you are lucky you may also see some kaka and kereru.

As with the pohutakawa, our kowhai has relatives in other parts of the world, like Chile and Hawaii. Even so, many people consider it to be our national flower. NZ has eight kowhai species of it's own. The species in Tuateawa is known as Kowhai tetraptera after the four wings on the seed capsule although this is also found on other species.

Kowhai seeds have an undeserved reputation. They do contain a poisonous alkaloid but there is not a single record of stock or human death from eating the seeds. Two people have become rather poorly though as a result of eating a meal made using a spoon of kowhai wood.

Kowhai trees are mostly found along streams and other waterways. They do prefer well drained situations but their seeds and seed pods are well adapted for distribution by water. The seed capsules float, and so do most of the seeds when pods rot and release them. Viable seed from NZ has been found washed up on the shores of the Kermadec and Chatham Islands.

Dr. Eric Godley, a kowhai specialist, has expressed concern about the decline of kowhai in some locations in NZ, particularly in areas of intensive management. The status of kowhai in Tuateawa seems to be an open question . There are plenty of mature trees. There are also quite a lot of small seedlings to be found. I do wonder how many of these will become saplings and then young trees. Rabbits are more prevalent since predator controls have been introduced.

We have planted kowhai on our section that have been ring barked by rabbits. In one kowhai grove we visit there are no saplings present to replace the old trees that are falling prey to borer beetles and the wind. An heavy infestation of kikuyu could be stopping the kowhais replacing themselves in this location.

Of course, we can always grow our own replacement plants. There is no shortage of kowhai seed in Tuateawa. The seed coat does need to be damaged before germination can occur. Once it is though, germination is rapid. Some use nail files and others sharp knives to abrade the coat. Another alternative involves using coarse grade sandpaper. If you place seed inside a piece of sandpaper folded on itself, a rubbing motion, on a flat surface, roughens up the surface. If the seed is then placed on some soggy paper towel in an old saucer you can see if the treatment has worked. A germinating seed swells up as it takes in water. It also looses a yellow dye. If you see these things happening it's time to plant the seed!