How Should I Plant My New Tree?

Article #5 in the Series “So, You Want to Plant a Tree!”

Peter Duinker, Halifax Tree Project, 2023-05-26

There is no need for me to present here a detailed how-to guide for putting a little tree in a new place, for example your garden or yard. That’s not because everybody already knows how to do it correctly, but rather because there is so much guidance out there, particularly on the internet, on this topic. For tree nerds like me, it is important to know the details and why the guidance is what the guidance is, so I recently bought “The Practical Science of Planting Trees” by Gary Watson and E.B. Himelick (2013, published by the International Society of Arboriculture). An excellent book that I will re-read next winter during my annual hibernation in front of the woodstove!

 Just to get you started, here are a few reputable websites where you will find tree-planting advice:

1_ HRM - https://cdn.halifax.ca/sites/default/files/documents/transportation/streets-sidewalks/cc_tpw_urbanforest_brochure_digital.pdf

2_ Tree Canada - https://treecanada.ca/resources/tree-planting-guide/

3_ ISA - https://www.treesaregood.org/Portals/0/TreesAreGood_New%20Tree%20Planting_0621.pdf

Let me offer just a few tips that are covered in the planting-advice brochures but could use emphasis. First, don’t volcano-mulch the little trees. Whatever mulch you might instal (which is a good thing) should go no higher than the root collar which is where the trunk gives way to the roots. Root bark should be covered with mulch or soil, whereas trunk bark should be exposed to the air.

 I am in favour of both tethering and protecting a small tree. Tethering is needed if you plant trees that are, say, more than a metre tall, just to give them some support until the roots are well established into the soil surrounding the pit you dug for the tree. Probably 2-3 years is enough. Tethering longer than this can prevent the tree, on its own, from responding properly to wind by strengthening the roots and trunk in appropriate ways. In locations where there could be vandalism, machine damage (such as grass-mowing equipment), and dog-peeing, I would recommend a few stakes around the tree to deter such damaging agents. My approach is pictured below. This young red oak, near the street, is tethered gently to a steel T-bar stake, protected by two other short 2”x2” wooden stakes, and mulched. I will probably remove the tether in 2024 but leave the stakes until the tree has thickened its trunk considerably.