The roots of a Japanese Maple are the lifeline of the tree, but they can also get a little ambitious if you don’t keep an eye on them. Understanding how these roots behave is the secret to a healthy tree and a damage-free garden. Here’s the lowdown on how they grow and how to keep them happy.
What kind of root system does a Japanese Maple have?
Unlike many of our native maple varieties, the Japanese Maple is a shallow-rooted tree. Instead of diving deep into the earth, its roots spread out horizontally just beneath the surface, forming a wide, flat root plate to soak up moisture. You’ll want to keep this in mind when picking a spot and planting your tree—make sure that planting hole is nice and wide!
How deep do Japanese Maple roots actually go?
Most of the root action for a Japanese Maple happens in the top 8 to 20 inches (20 to 50 cm) of soil. Because they stay so close to the surface, you have to be extra careful if you’re digging them up or trying to plant flowers underneath them. One wrong move with a shovel can easily nick that delicate root plate.
How can I keep the roots healthy and well-fed?
To give your tree a boost, spread some compost over the root zone and add a layer of mulch. Compost is like a health shake for the roots, but steer clear of high-nitrogen fertilizers—too much nitrogen can actually make those stunning leaf colors fade. Mulching is a lifesaver because it prevents water from evaporating during dry spells. Bark mulch is great for holding onto moisture and slowly releasing nutrients back into the soil.
How do I keep the roots from spreading too far?
If you’re worried about the roots taking over, you might want to consider a root barrier. Since they are shallow growers, these maples love to stretch out and can eventually crowd out neighboring plants. To keep things contained, install a root barrier right when you plant, or simply grow your Japanese Maple in a container.
Can I transplant a Japanese Maple with its roots intact?
You can definitely transplant a Japanese Maple while it’s still young. However, once the tree reaches a certain size, the root system becomes so massive that moving it is either a huge chore or just too stressful for the tree. If you do decide to move one, treat those roots with kid gloves!
Pro Tip: Don’t forget the drainage!
Want to do your Japanese Maple a huge favor? Add a drainage layer of gravel or expanded clay pebbles at the bottom of the hole. This ensures that extra water drains away properly, preventing the dreaded “wet feet” (root rot) that can happen when water pools around the roots.