Plant some pakeha trees

Broad-spreading deciduous exotic trees offer stock the chance of shade in a scorching summer, while avoiding it in winter, Hawke’s Bay farmer Peter Arthur writes.

Years ago, while fishing at Lake Rotoiti with my cousin Chris Biddles, the kids from next door came down with a battered old slug gun bound up with tape and string and asked if they could shoot some birds in a clump of bamboo.

We said ‘yes’ but asked them not to shoot any of the native birds including the wood pigeons. Their reply was simple. “We will only shoot the pakeha birds” which they proceeded to do with great accuracy, despite the state of the weaponry.

The trees I’m going to write about in this article, I am going to term ‘pakeha’ trees. The Concise Maori Dictionary defines the word ‘pakeha’ as ‘foreign’ or ‘foreigner, usually applied to a white person’.

I dislike the term ‘native’ when describing trees as all trees are native to somewhere. Indigenous is a better word.

We have climate change upon us. It was called global warming which was more apt as the New Zealand weather is getting hotter and drier, with the occasional flood thrown in. As for climate change, it is always changing, and is a force more powerful than man. All we can do is try and adapt and take preventative measures.

One thing livestock farmers can do is dot plant pakeha trees in their paddocks to provide shade from the searing summer heat. This last summer we had several days with 38C heat and there were no sheep to be seen in my front paddock – they were all under the shade of scattered oaks, elms, European limes, sweet chestnuts and plane trees.

I have never measured, with a thermometer, the difference in temperature but it is noticeably cooler under the shade of a tree than in the open paddock.

Just like people, livestock suffer from heat stress. You will have seen sheep in a treeless paddock with their heads in the shade of a power pole, post or even a batten, seeking some respite from the heat. The poor things are almost being cooked alive.

The most useful thing we can do is prepare for the worst and expect it to get hotter and in many areas, drier. There will probably be more floods and storms with most of the water rushing out to sea.

We need to conserve stock water, and by providing shade the stock will be drinking less and be much more comfortable, like you sitting by an air conditioner with a beer on a stinking hot day.

The first thing with planting a shade tree is to make sure it is not going to interfere with any tractor work. The second thing is it needs to be deciduous so there is minimal winter shading of pasture. This puts paid to pines, conifers, eucalypts and other evergreen trees. NZ natives are also out for dot planting as they nearly always require a protective nurse crop to become established.

A big, broad-spreading pakeha tree is needed. The cheapest and quickest growing are the poplars and willows, just a few trees to each naked paddock. Auger a hole, pop in the pole with a protective plastic sleeve, ram the dirt in hard and all is done. Another ramming of the dirt in the summer can be needed if the soil is cracking open. Cost per tree and protective sleeve is about $10.00.

The next easy to grow tree is the London plane (Platanus acerifolia) which can be planted from cuttings and treated like a poplar or willow.
I have collected cuttings when the plane trees in Hastings were being pollarded, put them in a nursery bed for a year to grow roots, then planted out. You don’t want plane trees close to buildings with gutters as the huge leaves soon block them.

The plane, which can grow 35 metres tall, is eventually a very wide-spreading tree, long-lived (400 years) and tolerates the wind and most sites. I had a 20-year-old tree totally defoliated by spray drift and gave it up for dead. Two years later it was as alive
as could be.

My next choice is for deciduous oaks, which, although slower-growing can provide spectacular autumn colour. There are about 600 different oaks with about 300 of them coming from Mexico. Some of these Mexicans are growing at about the same speed as poplars but they are evergreen.

The American pin oak, (Quercus palustris) is the most commonly seen, and though good for colour has a birds nest of small side branches. The Northern pin oak, Quercus ellipsoidalis, the leaves of which look the same, has a much better branching habit. Livestock and ducks both enjoy eating acorns.

I have a steep northerly facing paddock dot-planted with about 200 honey locusts (Gleditsia triacanthos) and although the trees are not big they give shade and have long leathery seed pods which cattle enjoy when they eventually fall.

Sweet chestnut (Castanea sativa) is a broad-spreading tree and sheep will eat the nuts. I’ve heard some say the prickly burrs can get stuck in the wool but I’ve not had that problem.

Something I have planted for the first time is Acer Freemanii ‘Jeffers Red’, a fast-growing maple reaching 25m with good autumn colour and which tolerates dry windy sites. Appletons Nursery in Nelson supplied me with 10 1m-tall plants at about $12 each.

Some of the ashes are very colourful but the best Claret Ash, tends to blow to bits in the wind. The Wych elm, Ulmus glabra grow very tall and can provide good autumn colour. Avoid Ulmus procera which can send up suckers at least 50m from the original tree.

Though slow-growing the maidenhair tree, (Ginkgo biloba) is tough and provides stunning yellow autumn colour. Fossil remains show it has been around for the last 290 million years surviving ice ages and hot patches. It has learnt to live with climate change without any help from politicians, scientists or bureaucrats and we could try and do the same. Plant some pakeha trees.