Shared by Daniel Charlton, Warner Parks Tree Trust Program Coordinator
It's tree planting season here in Warner Parks! Fall and winter are a great times for planting. The trees are dormant, which helps them cope with the shock of being transplanted and gives them plenty of time to establish their roots before the hot growing season. Here in the Park, we're planting a variety of sizes, from tiny bareroot seedlings to small and mid-size container-grown trees, up to large balled and burlap wrapped trees. This post will walk you through the process of planting a container-grown tree, the type of tree you're most likely to plant around your home or property, and give you a few tips to help ensure your tree stays healthy as it grows.
12 balled and burlapped trees that were generously donated to Warner Parks by the Root Nashville campaign
When deciding where to plant your tree, look up. Some trees prefer to grow in full or partial shade; others won’t grow in anything less than full sun. Check the requirements for the species you’re planting. Watch for any obstacles the tree may grow into as it matures. This guide from the Nashville Electric Service can help you decide how far away from power lines to plant.
You can use the handle of whatever tool you’re digging with to measure the width of the tree’s root ball. You don’t need to be exact; you want to dig the hole about twice as wide as the root ball and just the depth of the roots. Dig the hole shallow to start with. It’s easy to keep digging deeper if you need to, but if you dig the hole too deep and then fill it back in, the tree usually settles lower after a few rains and will end up being planted too deep.
At the base of the tree, you’ll find what’s called the root flare. Picture a child’s drawing of a tree; it doesn’t go straight into the ground like a pole; it flares out at the base.
You may need to scrape some dirt away from the trunk to find the root flare. Make sure this root flare is planted at or slightly above the level of the surrounding soil; burying it can cause the trunk to rot.
Dig the hole deepest in the center, with sides sloping inwards. Remove any rocks or roots from the hole and break up any large clumps of dirt as you dig. You’ll add this dirt back into the hole later, and it’s easier for the roots to grow through looser soil.
Gently remove the tree from its container and look at the roots. If you see mostly dirt with a few roots here and there, the tree is probably ready to plant. If you see a thick mass of roots growing in a circle all around the root ball, you’ll need to break them up. If the roots are too thick to break up with your bare hands, a shovel or some pruning shears should do the trick.
This rootbound tree needs to have its roots broken up before planting.
Cut the roots vertically all around the root ball and try to direct them outwards. This helps develop a wide and healthy root system and keeps the tree from choking itself as it grows larger. A lot of people try to avoid this step for fear of hurting the tree, but the greater danger is being too gentle, which can kill the tree a few years down the road. By being rough with it now, you’re saving its life. Try to keep the soil around the root ball in place as you break up the roots and be ready to get the tree in the ground immediately after this step.
Once your hole is the right size and the roots are broken up, place the tree in the hole. Positioning is up to you: if you’re more practical, arrange it so that its branches will catch plenty of sunlight; if you’re more creative, position its most attractive side toward where you’ll see it most often. Check that the branches are splayed out as much as possible and not tangled up in each other.
Make sure the tree is standing up straight! It’s surprisingly easy to forget this step. Walk all the way around the tree. It might look straight from where you were standing but have an obvious lean from another side, and that’s a lot harder to fix once you’ve filled the hole in. This is easiest with two people; one person can hold the tree steady while the other person checks that the tree is straight and then fills in the hole.
Add the dirt back to the hole a little at a time, pressing it gently in as you go. This is a balancing act; if the soil is too loose, the tree can start to lean or fall over, but if it’s too compressed, the roots have difficulty growing. A firm touch is enough; stomping is excessive.
Patting the soil gently into place
If you didn’t compress the soil too tightly, you should have a good amount left over. Use this to create a dirt ring 5-6 inches wide around the base of the tree. It will look like a donut on the ground around the tree. This helps catch water and direct it inwards towards the tree’s roots. Cover this dirt donut and the area inside it with 2-4 inches of mulch. This helps retain the water they need, protects them from extremes of heat and cold, and reduces competition from weeds. Beware of over-mulching, though. You’re probably used to seeing “mulch volcanoes,” big hill-shaped mounds of mulch piled all the way up to the trunk of the tree. These can cause lots of problems for trees, holding too much moisture and making the tree more susceptible to insects, diseases, and rot. Make donuts, not volcanoes!
A ring of mulch covers the ring of dirt, with only a small amount of mulch in the middle. A wide mulch ring also helps protect from accidental lawnmower or weed eater damage.
Once you’ve planted your tree, make sure you give it a good watering. You can do this all at the end, or little by little as you fill the soil back into the hole. This helps mingle the soil from the container with the soil in the new site and helps the roots bond to the new soil. Pour the water slowly until it starts to pool; then pause to let it drain and water it again. You want all the roots and the soil around them to be thoroughly soaked.
Most importantly, for the first few years after planting, water your tree regularly during the growing season. Plan on once a week unless you get significant rainfall. After three years or so, the tree should be well established and have a wide enough root system to get the water it needs from the rain without additional watering from you.
Learn more about Warner Parks Tree Trust program.
Further resources:
Nashville Electric Service's guidelines for planting around power lines
Planting a Tree - International Society of Arboriculture
Proper Mulch Technique - International Society of Arboriculture