Evergreen tree is perfect weather protector

THE other day I had to take out my hedge trimmer and mount an assault on some trees and shrubs growing around the patio on the west side of the house.

The growth has been good this summer and they were blocking the light coming in through the dining room window and obscuring the view.

You can see across a meadow, across a raised bog and over to a flat horizon that’s over 20 kilometres away. I love having such a distant horizon and a view without any buildings or signs of human activity. It’s the next best thing to living on the seashore. But it does have its down side.

In winter screaming gales tear in from the west, buffeting the house and scorching the plants. So over the years I have experimented with different trees and shrubs to provide some shelter from the wind. Most of the experiments have been failures. Some February gale eventually cuts them back and they wither and die.

But there are also a few successes, otherwise I wouldn’t have had to take out the hedge trimmer to reclaim the view. The main plant I attacked was a small and extremely hardy evergreen tree – a pittosporum.

There are about 200 species of pittosporum – sometimes called cheesewoods – growing wild in the world, and a good few cultivated varieties as well. They come from Australia, New Zealand, south-east Asia and a few from Africa. Most of them are no good for providing shelter in Irish gardens because they’re not frost hardy.

But one or two of the New Zealand species are quite astonishingly tough, providing year-round wind protection and even thriving in coastal areas. Pittosporum tenuifolium is probably the best of all, along with cultivated varieties with golden or silver leaves that have been bred from it.

But garden plants with odd-coloured or variegated leaves are never quite as strong as ones with old-fashioned green leaves because they lack the full amount of green chlorophyll needed for efficient photosynthesis. So I grow the un-improved strain of pittosporum for shelter.

The pale green leaves look a little like holly leaves without the spines and in summer it produces tiny white flowers which seem to be very attractive to bees and other nectar-loving insects. The very dense evergreen foliage not only shelters me, it also provides excellent roosting and nesting cover for small birds. The tree on the patio is the base camp for a pair of wrens.

Pittosporums (apparently the correct plural form of the name) are quite small and slow-growing – a 10 metre specimen would be old and large. They take well to being clipped and can be grown as a hedge.

The crinkly leaves are regularly used by florists to provide the green foliage in floral decorations. There is also an intriguing species called the petroleum nut (pittosporum resiniforum) which yields a form of petrol which is claimed to be superior for use in engines to petrol derived from crude oil. I don’t know if the petroleum put will grow in Ireland (if anyone does I’d be interested to hear from them) but some people are touting it as a possible source of bio-fuel to replace oil.

As a wildlife gardener I usually implore people to plant native trees and shrubs, largely because they support more invertebrate species that are the base of the food pyramid in the garden. But pittosporum provides so many benefits in our windy climate that it has to be one of the exceptions.