How to properly plant a tree: here are 6 things to know, from type to timing
It seems pretty simple to plant a tree. Dig a hole. Drop in a tree. Fill the hole. Add water. Go back inside and have a beer.
What could go wrong?
Yet year after year, we see trees planted incorrectly, dooming them to either a very short life, or, if they actually live through the first year, a medium life of annoyingly poor performance. And, really, there’s no excuse.
You see, we’ve been planting trees since the Babylonians hung a few gardens from the top of the Tower of Babel. And not that we have anything on those Babylonians. After all, they had that Hammurabi guy, and that math stuff they did on clay tablets, and those hanging garden things. They were pretty advanced people in their day.
But if we’ve been planting trees for a few thousand years longer, shouldn’t we have learnt a thing or two by now?
So, if someone out there will hold my beer, I’ll try to get us back on par with our Mesopotamian brothers and sisters and give ya a few pointers on how to properly plant a tree.
How to choose a tree
Just because it’s at a proper nursery doesn’t necessarily mean it’s a perfect specimen. Trees get damaged in shipping. They may have been grown in a container too long leading to tons of those deadly circling roots just inside the container.
The nursery owner can’t unpot every tree in the place, so look for trees with the trunk centered in the pot or the root ball. Inspect the trunk to make sure there aren’t any major gouges to the bark. Look for a tree that is well pruned and looks reasonably vigorous.
How to check tree roots before planting
Even beer-drinking Babylonians knew that you can’t grow a good tree with bad roots.
First, inspect the base of the trunk to make sure you can locate the root flair — where the trunk widens to meet the root system. A properly planted tree sits with its root flair visible when you’re done planting. You can’t determine how deep to dig your hole until you find the root flair. So whether you have a container or B&B (ball & burlap) plant, gently investigate to top of the root mass. And don’t be surprised if your B&B tree has 6 inches or more of loose soil above the root flair.
Mechanized cultivation systems can sometimes lead to a bunch of loose soil ending up on top of that magical flair. Gently brush away any of that soil — it won’t have any roots in it anyway. Once you’ve exposed the flair, measure the depth of the actual root ball you’ll be planting.
How wide, deep should a hole be when planting a tree?
Planting depth is key to a successful long-term tree. You want to dig a hole so the root ball sits on undisturbed soil. If you break up the soil in the bottom of the hole, the ball will settle over time with the result being the tree being planted too deeply in the hole.
Make the hole as wide as you reasonably can. The tree roots will grow mostly out, not down. A hole twice as wide as the root ball is a good place to start. More is better. And since you know the location of the root flair, you’ll know just how deep to dig. And it’s never a bad idea to go even a couple of inches shallower than that to allow for a bit of settling after planting.
How to plant balled, burlapped trees
For a container-grown tree, you’ll want to gently tap the container off the root ball so you can inspect the roots. And this is the hard part — you’ll want to beat the living Bejezus out of the outer inch or so of that root ball.
Really. Roots tend to circle along the inside surface of the container and if you don’t break up that circling mass, you’ll end up with a wadded mess of roots somewhere down the road, and a tree that will prematurely fail.
A soil knife or utility knife does the trick nicely. Four or 5 vertical slits the length of the root mass, evenly spaced around the ball.
For a B&B tree, it’s a bit different. No circling root problem with these. Place the root ball next to the planting location, gently undie any twine from around the base or the trunk and loosen the burlap. Dust away any loose soil on the top to expose the root flair and finalize the depth of your planting hole. Then gently place the ball in the center of the hole.
How to backfill around a tree
This is where I start to get the hate mail.
If you have excellent soil (lucky you!), go ahead and backfill the planting hole with that mythical magic stuff. If you’re like me, your yard is made up of the kind of modeling clay the Babylonians used to make those math homework clay tablets. That stuff needs an organic amendment — about one third by volume — thoroughly mixed with it to give your tree a fighting chance.
And while I’m generating hate mail, here’s the other piece. As you backfill around the root ball, there’s always the question about wire cages and burlap, what to leave behind and what to remove.
Here’s my technique: Backfill half way, gently tamp the backfill in place. Then cut and remove the burlap and any cage from the upper half of the ball before backfilling the rest of the way.
How and when to stake a tree when planting
Simply put, stake trees low (1-2-feet above the ground) to keep the ball in place and let the top sway in the breeze. That swaying encourages trunk and root growth. Staking shoulder height leads to spindly trunk growth that may not sufficiently support the tree as it grows. And no wires, please. Support with a wide strap to distribute the pressure on the trunk, and pad under the strap for extra protection.
That’s it. Pretty straightforward. Might not be written out on Hammurabi’s tablet but this is close enough. Now before I take any questions, who’s holding my beer?
Paul Cappiello is the executive director at Yew Dell Botanical Gardens, 6220 Old Lagrange Road, yewdellgardens.org.