9 Common Tree Planting Mistakes
There are few things as satisfying as planting a tree. Every time I make the trip back to Chicago I visit the site where I first hosted an Arbor Day celebration. We planted a Tulip Poplar (Liriodendron tulipifera). It was a personal choice, remembering the big Tulip Tree at the end of our sidewalk as a kid. The tree we planted on Arbor Day many years ago is thriving and beautiful. We took the time to plant it well and the tree and everyone who passes it is benefiting from it.
Within sight of that Tulip Poplar is another tree, a Black Hills Spruce (Picea glauca var. densata) that was planted only a couple of years later. It, however, is not thriving. The tree was planted too low, in a hole too small. My hunch is that the burlap and basket were not properly removed and the tree did not see the kind of care after planting that the Tulip Poplar received.
The way we place trees in the ground makes an enormous difference in their future success in our landscape. Unfortunately, I see basic planting mistakes all the time in our industry, mostly by those who will collect a check as soon as the plant is in the ground and their truck is off the lot. For those of us who will care for the tree for the years to come, we have much more invested in the proper planting of our trees. Here are nine common mistakes to avoid when planting your next tree.
9 Common Tree Planting Mistakes
Wrong Tree/Wrong Site
We’ve all seen it – a tree planted where it shouldn’t have been; High growing species planted under power lines, wide-canopied trees planted right against a building, or fragile trees planted in a parking lot, bound to drop a branch on car. The tree was set up to fail, and to give us headaches in the future. Or maybe the tree species or variety selected wasn’t a good fit for the climate or micro-climate of the planting site.
Before you plant, understand your site and the goals you have for the tree. Picture what you want the site to look like in the next ten to fifty years and see if the tree is the right fit. Look up your tree’s potential height, spread, and ideal growing conditions. Know your tree and know your site. If they aren’t a good match, find a pairing that will work will together.
To find the right tree for your site, use the Urban Forest Ecosystems Institute’s Tree Selection Guide.
Hole Too Small
Once you’ve selected your site and your tree, it’s time to prep the site.
From here on out, a little understanding of how your tree is going to grow and respond to a transplant will go a long way. The tree’s root system in a typical root-ball (like the picture here) has been severely decreased in the transplanting process. This tree’s initial response will be new root growth to support the tree’s leaf canopy. You need to give those new roots every possibility to succeed in growth and establishment in its new home.
One of the best ways to do this is to give the tree plenty of good soil to grow new roots. The Arbor Day Foundation recommends a hole two to three times as wide as the root-ball and to rototill an area five times as wide as the root-ball. This provides good loose soil for the new roots without competition from other plants. Of course, this might not always be possible. Do the best you can and let those new roots thrive.
Find the Arbor Day Foundation’s guide to planting balled and burlapped trees here.
Hidden Root Flare
The root flare (where the trunk ends and the roots begin) should be visible. If your tree has been dug with a spade at a nursery, and burlapped and placed in a wire cage, the soil may have been pushed up around the tree’s root flare. You need to expose it. Naturally growing trees will begin to flare just above the ground level (see picture here or the next tree you pass outside). This is what you want your tree to do as well. Scrape the soil off of the root-ball until you expose the root flare. Now make sure you plant the tree at the right depth so the flare sits above ground level.
Failure to do this will inhibit the tree’s growth and health and keep it from reaching its full potential. The trunk is now in the ground. Moisture from the ground will rot the buried trunk and invite insects and fungus to live there as well. The roots are deep and will grow up around the buried trunk, choking the tree.
Just because you found the root flare doesn’t mean you can’t plant the tree too deep. A tree planted too deep will never thrive.
Carefully measure the depth of your root-ball from the bottom of the ball to the root flare. Then carefully measure your hole. It’s better for the root flare to be slightly higher than ground level than to below ground level.
Compact the bottom of the hole to avoid settling. If, after all this, the tree is still too low (it’s annoying, I’ve done it), pull the tree back out and raise the bottom of the hole. This will mean the difference between a thriving happy tree or one that never quite establishes correctly.
Burlap and Wire Not removed
Those roots are going to have trouble breaking through that wire basket and burlap. Sure, the burlap disintegrates, but it takes many years. And eventually the roots will grow through the wire basket – not ideal for the tree. When planting a balled and burlapped tree, remove the wire basket if possible. If not, push it far down into the hole. The basket will have little notches in it – those are for the end of your shovel, to make it easier to shove the wire down into the hole. Then take all of the roping and burlap completely off.
I once visited a campus where almost every tree planted in the last five years was failing. I pulled back the mulch from every tree and found the rope from the burlap still tight around the base of the tree. The rope was chocking the trees as they tried to grow. I cut all the rope off, but I’m sure all of these trees still had a full layer or two (or more) of burlap and a wire cage around their root-balls.
Root-Ball Not Broken Up
While this is important when planting any type of tree, it is vital for containerized (or potted) trees. Next time you pull a plant out of a container, notice how the roots are growing – likely in circles. They had no where else to go in a round pot. Now guess where they will keep growing if you just put that root mass in the ground as-is. Right, in circles. Or at lease they will continue to stay tight to the plant.
Using your hand or a shovel, pull those roots apart. It’s okay to sever some of them. They will regrow out into the loose soil in that nice big hole you dug earlier.
Roots need to grow out into the soil to support the tree. Root bound plants can fail to send out enough of those supporting structural roots to support the plant.
After all that work, please make sure your tree is straight. Tip: Line up the trunk with the corner of a building – any solid structure will be straight up and down. Or use a level if you need to. If the tree is large, pry one side of the root-ball up and place more soil underneath. Look at it from every angle before you walk away. Come back in the following days and weeks and check for level. If you have to stake a tree to keep it straight, do not leave the staking on the tree for more than one year.
Not watered correctly
Your tree is thirsty and will need a lot of water in the upcoming weeks (or more). After you have back-filled your hole, create a water-holding berm around the perimeter of the root-ball. Soak the entire area. Don’t forget the soil around the hole. You want to encourage those new roots to grow out. If you only water the root-ball and the area of the original hole, those roots will not be encouraged to grow outward. For the first year keep the entire area moist, making sure the tree gets a good soaking every week or two.
A note on watering bags: Don’t think that just because you threw a bag around the tree and fill it up once in a while you are watering properly. Watering bags have their place, but only deliver water to the base of the tree and usually don’t hold enough water to adequately soak the entire area. Tall bags can damage small trees by placing too much weight against the trunk. Bags can also trap moisture against the trunk, inviting insects and disease. Your best bet is to hand water.
Tags not removed (or water bags or staking)
Finally, take everything off of the tree as soon as possible. See the string coming out of that branch in the picture? Probably an old nursery tag (yes, they’re all plastic now). Your tree wants to grow. Don’t keep anything attached to it that will inhibit its growth. Plus it just looks tacky to see staking left on or green bags sagging around a tree in the winter. You did all that hard work, take the last step and let the tree grow free.
And if you want to keep the tags for warranty (and you should), just create a file folder in your desk and keep them there for a year.
For more information about proper tree planting and tree care, please visit our Resource Page, or one of these helpful sites: