Here’s something I’ll admit freely: for half my career as a certified arborist, I didn’t know how to properly plant a tree. So if you’ve been doing it wrong, you’re in good company.
The truth is, proper tree planting is one of the most misunderstood things in this industry — not just by homeowners, but by certified arborists, landscapers, contractors, and city planners. If it’s not put in the ground right, then nothing works right and all systems are in failure mode. Most improperly installed trees will remain in the ground for upwards of seven to ten years before they die from the installation itself — and nobody ever connects the dots.
Before you dig a single inch, there’s a question worth asking: what kind of tree should you be planting in the first place? “The right tree for the right place” is a golden phrase in the arboricultural community, and it matters more than most people realize. The wrong species in the wrong spot creates problems that no amount of correct planting technique can fix. We cover tree selection in detail in our guide to planting a new tree — but once you know what you’re planting and where, technique is everything.
The most common mistake? Digging the hole first. Most people dig this giant hole, wheel the tree over, drop it in, and call it done. I get it — it feels logical. But it skips the most important step of the entire process.
Before you touch a shovel, you need to find the flare.
The root flare — sometimes called the root collar — is where the tree meets the earth. It’s essentially the heart system of the tree. It’s how the tree pumps water up and down, how it expands as it grows, and most importantly, how it breathes. Trees require oxygen. A lot of people think trees just need carbon. Carbon is their food source, but they breathe oxygen just like us. Bury that flare, and you’ve started a slow process that can take seven to ten years to kill a tree — and most homeowners never connect the dots.
When you buy a tree from a nursery, there’s a good chance the flare is already buried. Nurseries often add excess soil to the pot. You might dig down three, four, even seven inches before you hit the true flare line. Along the way, you’ll often find girdling roots — and here’s what’s actually happening: the tree is making the most of a bad situation. Planted too deep, the root system sends roots up and around in search of water and oxygen. Over time, those roots begin to circle the trunk, slowly choking it. That little itty bitty root, left alone, will eventually kill your tree.
So the first job is to expose the flare. Use a sod knife to cut away the excess soil. Tease out those circling roots and sever the ones that are wrapping around the trunk. Butterfly the roots outward. You want them pointing away from the root ball, not circling it. They don’t need to be fully extended — they just need to be heading in the right direction.
Now you can measure the root ball and dig your hole. The rule is simple: twice the width of the root ball in diameter, and only as deep as the root ball itself. The bottom of the root ball has to sit on undisturbed soil. That’s the key ingredient. And the top of the flare needs to sit about an inch above finished grade, because the root ball will settle over time.
One more thing about the hole itself — after you dig it, score the sides with your shovel or a Pulaski. Digging can glaze the soil walls, making them almost like ceramic. Roots can’t break through that. You’ve essentially planted the tree in a pot underground.
When you backfill, use the native soil from that hole. Don’t bring in compost and fill the hole with beautiful amendments. You’ve now created a pot in the ground because the roots will only want to grow in good soil — they’ll stay inside that area and never chase water, never grow. Native soil goes back in the hole. Compost goes on top, pulled away from the flare so it never buries it. Wood chips go on top of that, simulating the forest floor — because that’s the environment a tree actually needs.
Water outside the root ball. Not in it. Make the roots look for the water.
One of the number one problems I see with newly planted trees is too much water. Most trees are suffocating. They’re too deep, they’re overwatered, and the combination creates root rot and anaerobic conditions where the roots can’t breathe. If you suspect your tree was planted too deep and the flare is already buried, that’s something we can fix. Our root collar excavation service is specifically designed to expose a buried flare, remove girdling roots, and give an established tree a second chance.
Plant it right the first time. Everything else follows from there.