I was horrified by the news. I’m a great fan of the Halifax Public Gardens, an extraordinary public park and garden that I visit every time I’m in Halifax, Nova Scotia, Canada’s east coast metropolis. And much of its charm come from the extraordinary trees that decorate it. Well, vandals broke into the Gardens on the night of July 25 and 26, 2022 and tried to kill 30 historic trees, ranging in age from 50 to 200 years old.
The first report I heard was on CBC radio and it just mentioned “damage.” So I thought, “a few branches broken off, maybe some bark peeled off. Most trees can handle that. It won’t be that bad.” Then I heard the word “girdled” and my blood ran cold.
It’s the one word you don’t want to hear when it comes to a beloved tree. For girdling is not just superficial damage. it leads to the tree’s death. And it is only used to kill a tree, to make sure it can never come back.
What Is Girdling?
Girdling, also called ring-barking, involves is the complete removal of a ring of bark all around the trunk. The bark is where you find the phloem, the outer transport tissue, the one that carries sugars from the leaves that manufacture them to the roots below. With the bark gone, no more carbohydrates will be able to flow down to reach the roots.
Bit of Botany
Just a quick note to help you better understand girdling. Something you were taught in high school biology, but have had plenty of time to forget!
Sap rich in sugars flows down from the tree’s leaves to its roots via the phloem, tissus just inside the bark. Water and minerals, on the other hand, are pumped up from the roots via the xylem, found in the cambium and the sapwood. So, if the bark and phloem are removed, sugars can no longer reach the roots, yet the leaves and buds can still get their fair share of water coming up from the roots via the xylem.
If the xylem, the inner transport tissue, is still intact (and it usually is in girdling), water and minerals can still flow up to the branches and leaves. Therefore the tree often looks fine at first. In fact, for over a year, you’d be unlikely to suspect what is about to happen. And that will occur suddenly, most likely in the second year, when the roots have used up any sugars that they had stored. Then the tree will suddenly die. Just like that! Apparently healthy one day and full of dying leaves the next.
All that’s left to do is to cut it down.
Arborists often use girdling to kill trees that sucker abundantly. That’s because it kills the suckers along with the roots, using up all their stored energy. Or because the owner wants the tree to keep standing after its death, perhaps as animal habitat. You never use girdling on trees you want to see live!
Who were these vandals? That’s the million-dollar question.
The police presume that there was more than one person involved. First, because much damage occurred in relatively little time. And secondly, carrying tree surgery out in the dark of night would slow anybody down!
The culprit apparently used a hatchet to strategically hack away bark from each tree. That’s hard work. Plus, you have to know just how far to go, and no further. And someone would have to have held a light.
Planning this attack therefore required someone with good knowledge of arboriculture. Believe me, I’ve girdled a tree before and it takes a lot of effort and concentration.
The park closes at night. That’s how the vandals were able to work undisturbed.
For me, this is the main question. Who would hate the City of Halifax or its people badly enough to want to kill 30 otherwise healthy and beloved trees in a public park? It has to be revenge of some sort. Otherwise, it just doesn’t make sense!
After all, no one will make a profit from this. It’s not as if a sneaky developer killed the trees so they could buy up the land cheaply after. The Public Gardens is the city’s main park. The space will not simply end up on the development market because 30 trees die. The park will continue to be a park, no matter what.
There’s really no logic behind the whole situation.
Can the Trees Be Saved?
Usually, girdled trees simply die. For safety reasons, the only logical thing to do in a public park would be to cut them down. However, there are a two possibilities I can think of that might save them.
The first possibility for saving a girdled tree is that, if the job weren’t well done and even a single strap of live bark still linked the bark on either side of the ring, the tree could grow new bark from that, eventually coming to wrap right around the tree. I’ve never seen that happen on a huge tree (and some of these are giants!) However, I’ve seen starving voles leave a single thread of live bark on a mature apple tree after a winter attack and the tree recovered completely.
So, since the vandals attacked at night, in the dark, maybe, in their rush and partially blinded by lack of light, they missed a few spots. Then the bark could grow back.
The second possibility would be to do a bridge graft. This is a graft of strips of live bark placed so that they reach from the bark below, then over the wound to join the living bark above. The bark has to be from the same species of tree. You could even use pieces of bark from the wounded tree itself to patch together a path that stretches from the top to the bottom.
If bridge graft takes, it will allow sap to flow again. The tree can then recover.
You can find information on bridge grafting here: Restorative grafting.
Currently, four trees deemed unrecoverable have been removed. In other cases, there appears enough bark left intact for the tree to survive. So, the authorities have only cleaned the wound and don’t plan to carry out any further interventions. But the majority will undergo bridge grafting later this summer.
Whatever decisions are made, dealing with this disaster will cost the Halifax Regional Municipality hundreds of thousands of dollars. Already, security cameras have been installed throughout the park and there will be 24-hour tree monitoring. The park also intends to plant substitutes for certain doomed trees.
And the park will take years—likely decades!—to recover its beauty. It’s just so, so sad!
All my sympathies to the people of Halifax!