I can’t tell you how irritated I get by this sentiment and I have seen it trotted out on several occasions recently. I get irritated because it rarely reflects a thoughtful position. And when you drill down, it only applies to trees. The speaker is just as likely to be drinking tea, coffee or wine – all from imported plant material. Indeed almost 100% of food we eat in this country comes from imported plants originally, even if it is now grown in the backyard. All our fruit, all our vegetables. All our meat is raised on pasture that is comprised of exotic grasses. Our grains are all imported species, as are our grazing animals. Even the dominant earthworms include many foreigners.
The vast majority of flowers that adorn our gardens or we buy to bring indoors to beautify our environment are of foreign origin. Our forestry industry is built on imported plant species.
Most of us live in very heavily modified environments and lead lives that would be totally unsustainable without imported plant material. This is not to say that we should not value and defend the very few pockets of land which remain with vestiges of original vegetation. These are of high value and we should be trying to protect, extend and restore these. But your suburban street, small holding or farm is never going to achieve native plant purity. And only planting dwarf fruit trees is not going to do anything to modify climate change or produce much of the oxygen that we breathe.
Alas, we are also a nation that, in the main, does not value trees and is ready to fell them at the first opportunity. “It is not a native,” is the justification often put up by the chainsaw brigade. (Or, if it is a pohutukawa, “it is a weed”!) That does not mean it is expendable and of no value. The world has even more beautiful trees than delicious food crops. And it takes a lot longer to grow a mature tree than a lettuce or basil plant. Some of those trees will adapt and grow in conditions where few of our native varieties will survive. Most of our native trees evolved in a forested environment, used to growing in company. There are not that many that will adapt to being single specimens or even a row of trees on an exposed coastline or a windswept road verge.
Particular contempt is often reserved for the Norfolk Island pine which does very well in many parts of New Zealand, looking handsome and healthy, even on exposed coastlines. Stop and think for a moment, before you reach for the chainsaw with contemptuous dismissal of this tree. It comes from the same plant family as our native kauri. It also originates on Norfolk Island which is about as close as any ‘foreign’ land gets to us.
A variation on this line is “I only grow plants that are native or edible”. Oh, okay. All of the above arguments apply. It is fine for you to declare that you only want a garden where every plant is either native or edible. Just don’t espouse this viewpoint as though it is the higher moral ground because it is actually quite a naïve position. Lawn and grass should of course be banned in such a garden, unless you are going to locate and harvest one of our native grasses.
What the world needs is more trees to purify the air, to provide oxygen, to enhance eco systems and the environment, to slow down erosion and to modify climate change. I understand that some people do not see any aesthetic value in trees. I don’t agree with that view but I see evidence of it so I must acknowledge that not everybody sees big trees as being something of beauty. But it is no accident that wealthy areas of cities are often referred to as ‘leafy suburbs’. Pretty much without exception, they have established trees to soften the hard concrete and sealed urban landscape. There are not many New Zealand native trees that will tolerate, let alone thrive in the harsh, urban landscape. Rule out exotic trees and all we will have in cities are nikau palms, kowhai and pohutukawa in northern areas.
The problem with trees is that they take 20 years to get established and upwards of forty to start reaching maturity. Yet they can be felled in minutes. But, still many argue, if they are not native, they are of no intrinsic value.