Maybe you just enjoy working with trees – but, like caring for pets, they need to be selected and treated differently according to their needs and intended purpose. Expert arborist Mark Roberts explains
It may surprise you, because it definitely surprised me, that there are dozens of scientific studies on the differences between cat people and dog people. As in actual peer-reviewed studies from reputable universities with articles published in credible magazines and journals. Who would have thought? I had assumed that the topic was confined to weekly publications that track the trials and tribulations of B-list celebrities. Seems I was mistaken.
I haven’t read any of these studies or articles, which, annoyingly, is probably a defining feature of one group or the other; ‘has a tendency to be sceptical and dismissive’. But it does pose the question, by not reading them, am I confirming that I am a cat person or a dog person? Luckily, some things are better left unknown.
I discovered this and then became distracted while thinking for an example to prove a point. Something so relatable that didn’t require a second thought. Although cats and dogs can be pets, they are quite different. We treat them differently, what we expect from them is different and, in turn, what they do for us is also different (which is nothing, if that pet is a cat).
So, I typed in the differences between cats and dogs into Google and was given several million results. None of which I needed for an article on trees.
Point of difference
From there, I had planned to build on the difference between working/farm dogs and pet dogs. A farm dog is basically a living tool that is taken out of the toolbox and used fora set of tasks then put back in the box at the end of the day. A farmer may have a favorite dog, in the same way that an arborist may have a favorite chainsaw, but the dog or chainsaw doesn’t come into the house at the end of the day and curl up by the fire. In short, there are differences between animals that we call pets and there are different uses for the same animal which may or may not be a pet.
When it comes to trees, there are equal and obvious differences. For cats and dogs, read oaks and pines. What we expect from those trees and how we manage them to achieve that expected purpose should also be different. Of course, for a tree to effectively fulfila purpose in the landscape, there must be a purpose for that tree to have. You might plant trees with a fastigiate or columnar form to create a sense of direction and scale, fruit trees for blossom but not fruit (Prunus serrulata v Prunus avium), conifers for summer cooling or deciduous trees for winter sun. You may plant trees that are designed to be removed, filler trees to aid establishment that are not intended to be part of the long-term garden. Or over-planting an avenue with the idea of removing every second tree in ten years. By knowing a thing’s purpose, you can work out how to manage it.
Don’t overthink it!
Currently, I’m working on tree planting for a new street. And what is the purpose of a street tree, I hear you ask? To which I’d reply, you’re overthinking this; there are many purposes and none, but as far as managing it goes, it’s just a street tree. The trees that I’m working with are still relatively small (2.5 to 3m), but they will grow. To be compliant in the future, very few, if any, of the branches that currently exist will form part of the mature tree. When we are pruning these trees, we are looking to create a single straight trunk. We removed the bigger side branches and keep the smaller ones – this is done to reduce the size of future wounds.
Knowing that all of the branches below 2.5m will be removed; if we leave the bigger branches, they will get bigger and so will the size of the pruning cut (the wound) when that branch is eventually removed. It’s all about thinking ahead and planning for things that will be there in the future. We can do this because the tree has a purpose. Of course, if it wasn’t a street tree, we might retain one or two of the bigger side branches and remove the smaller internal ones. One pruning style does not suit all.
Right and wrong
An old-school arboriculture belief was ‘the right tree in the right place’. That means, if you put the right tree in the right place, all your future worries will be gone. While not wrong, it is a bit of an oversimplification. Selecting the right tree [species] is always key.Get that right and half of your future worries will be gone. The other half, the new school of thought, is the importance of correctly managing that tree for the place where it is planted. For example, a mighty totara might be tightly clipped as part of a hedge, have its front and back pulled in to screen between two houses, have all of the lower branches removed to become a shade tree, or be centrally placed and left alone to become a specimen tree. Same tree but serving different purposes and managed through different styles of pruning.
Know the purpose of your tree and manage it accordingly, it’s as simple as that.
Mark Roberts is a qualified arborist and tree risk assessor with 25 years’ experience. Mark is also former President of the International Society of Arboriculture, and a past President of the NZ Arboricultural Association.
Mark now heads an arboricultural collective based in Dunedin: robertsconsulting.co.nz