How to Plant a Tree
It’s easy, isn’t it? You may have heard expressions like, Green side up. Or, Just dig a hole, put it in and watch it grow. But successful tree planting isn’t quite as simple as that. There are a lot of factors to consider, such as root health, soil health, mulching and post-planting maintenance.
Successful tree planting is one area of focus for the Greening the Landscape Research Consortium, a group of organizations from across Ontario’s urban tree value chain, including A.M.A., that are collectively driving solutions to improve the health and function of our urban landscapes.
Last week, the Consortium held its annual meeting. Members walked through a step-by-step guide for proper tree planting techniques, led by Jason Henry, Soil Scientist on the Plant Responses and the Environment team, and Clay Elzinga, Technical Research Assistant, at Vineland Research and Innovation Centre.
Tree Planting Best Practices
Remove the tree from its container and loosen the roots.
Inside the container, roots have nowhere to go but around the root ball. So don’t be shy about breaking them up with your fingers or with a shovel. It will signal to the tree that it’s time to get growing again.
To give roots the best chance, choose trees that were propagated in an air-pruning tray like the patented Air Tray® and RootSmart™ systems, available at A.M.A.
Dig a hole as deep as the root ball and twice as wide.
When Jason and Clay dug this hole, they were met with a surprise. It was full of water! A second hole, dug only a few feet from this spot, had been completely dry.
This goes to show you never know what kind of soil conditions you’ll find once you put the shovel in the ground. Clay added extra soil back into the hole to prevent the tree from sinking too deep into the ground.
Pro Tip: The tree should sit slightly above the hole.
Test that your tree is planted high enough by laying your shovel across the hole. The shovel should just touch the top of the root ball, and the root flare should be visible above the soil.
Backfill the hole with soil.
Replace some of the soil you dug out of the hole, then use your foot to gently press it down. You don’t want any air pockets! They can create deficiencies that damage the tree.
Add soil amendments.
Your tree has been carefully nurtured in a greenhouse or at a nursery since it was first propagated. Now you’re putting it out into the wild. Soil amendments can help improve the transition with a nutrient boost.
Jason recommends spreading a wide, thin layer around the tree. In this case, he used source separated organic compost. That’s the compost generated by a municipal food and organic waste program.
Time for mulch. No volcanoes!
Add about 10 cm of mulch around the tree, making sure to leave a 15 cm gap from the trunk. There’s a tendency to push the mulch around the trunk for “protection”. The truth is, doing this has the opposite effect.
Mulch volcanoes can lead to disease and decay by keeping the tree trunk too wet for too long. They can also prevent proper root flare development, which can lead to windthrow.
Stake your tree to provide extra stability while its roots spread out and down. It’s best to stake a tree for two years after planting.
And don’t forget to water! Newly planted trees require regular watering to help them get established. Water after you finish planting, and follow up with regular watering for the first two years.
Thanks to Jason Henry, Clay Elzinga, and fellow members of the Greening the Landscape Research Consortium for walking us through best practices in tree planting.
We want to see more, healthy trees! If you’re a grower who feels the same, get in touch. We can find solutions that will help you be good stewards of quality nursery stock. Browse our selection of nursery supplies here.