If we lay perfectly still for weeks and months, we know that our joints will stiffen and become less flexible. Movement will become difficult. Bending will hurt. Holding perfect still is bad for our health. And it’s bad for trees as well. Yet, every year hundreds of trees are splinted into immobility by well-intentioned gardeners. It’s no better for them than it is for us.
We have a tendency to regard a newly planted sapling as fragile, and we want to protect it as best we can. That trunk looks so flimsy, as if the first breeze will snap it in two. So what do we do? We stake it so it can’t wiggle. And that’s a very bad idea. Movement causes trunks to enlarge and strengthen. Trees that are firmly staked will never become strong.
Newly transplanted trees have lost a lot of roots, up to 90%! They can be top-heavy, and a strong breeze will push them over. The goal of staking is to stabilize the root ball so the tree doesn’t uproot in a strong wind while allowing the trunk to flex. The current advice says to stake the tree as low to the ground as possible. You can see how this is done in this photo from the Puget Sound area:
But wait, we live in Colorado, not Washington. Winds here can be severe, with sustained speeds of 40 mph and gusts much stronger, especially along Colorado’s Front Range. It’s not just the trees that need help to withstand such an onslaught! There’s a good possibility that, with the tree staked like this, the next storm could cause the tree to snap off just above the ties.
So what should we do? Stake the tree, but don’t make it very tight. Give it plenty of slack so it can move. After the first growing season, loosen the ties even more. By the end of the second year, the tree should be firmly anchored (wiggle the trunk to make sure the roots aren’t moving). It’s time to remove the restraints altogether. Note that the larger the tree is when planted, the longer this process takes.
Even after the tree is well-established, we can still unintentionally kill it. Friends had planted a lovely oak tree in their parking strip, and it had flourished for a number of years. Then, last spring it failed to leaf out. The twigs were brittle and brown inside. The tree was clearly dead. What happened? A quick glance downward confirmed my guess—this was death by string trimmer.
When grass is allowed to grow right up to the trunk of a tree, we need a way to mow it. Using a string trimmer seems like a terrific idea, but that whipping cord can easily cut through the bark and into the living layer underneath. When that damage reaches around the trunk, there’s no way for the tree to transport water from the roots to the leaves, or move food from the leaves to the roots. Girding is a sure way to kill a tree.
Some people place plastic protectors (shown above) around the lower trunk, but those can shelter pests and trap moisture. A better solution is to just leave a bare space between the lawn and the tree.
Of course, there are more ways to kill trees, although they’re not as common. Occasionally insects will attack a healthy tree. There are various fungal and bacterial diseases. Sunscald can split tender bark. Trees planted in lawns can be damaged by weed-killing herbicides applied to the turf. Roots can be damaged during landscaping or construction projects. And there’s one more, sadly common, problem most commonly seen along city streets and in parking lots.
Tell me, where are the roots of these crabapple trees supposed to grow? Under the cement? Where will they get air and water? I’m quite astonished that all the trees aren’t dead yet, although they look worse every year. (I pass them almost daily, as they’re in the parking lot of our local YMCA.)
Properly planted and cared for, trees have the potential not only to outlive us, but our children and their children.