Do you have space for a container tree?
So you want to plant a tree in your home, but space is tight, really tight. Fortunately, almost everyone has space for container trees. Whether you have a porch, balcony, or a small yard without an appropriate space for a tree or enough clearance from the house, there are many options for trees and shrubs to grow in a pot in Ontario.
Here are a few of your options.
Why Plant Container Trees?
Many of us in urban areas don’t have the space, or the soft groundcover, to plant a tree. Whether you’re a renter or new homeowner who inherited a paved-over yard, a condo dweller, a renter or townhouse resident with deck access only, or living in one of Toronto’s many homes with postage-stamp-sized outdoor space, ground space may be at a premium on your property. Even if you have more space, container trees can be a great way to dress up a deck or porch.
With a container tree, you get benefits of a backyard tree like aesthetics, oxygen, shade, and privacy or sound barriers. Many people plant trees in containers on decks to increase privacy or cut down on noise from neighbours.
What’s the Difference between a potted tree and one in the ground?
First, container trees are going to be smaller and stay smaller. You should pick a tree that is well adapated to growing in a pot. Planting a regular oak, elm or maple will result in lots of problems for the tree over time.
There is also the container or pot itself. Lightweight pots, like plastic, let you move your tree around more easily and cost less. However, heavier pots stand up better to wind, especially in winter conditions. A tree planted in a pot can be moved, but transplanting a tree is a lot harder. If you don’t have any ground to plant on, then clearly you’ll need to opt for a container tree. Make sure whichever pot you choose has drainage.
Trees in pots also need to be watered more frequently. They won’t absorb rainwater or groundwater in the same way as trees in the ground. Keep watering into winter until the soil freezes. If it thaws in a winter warm spell, give it some water at that time.
Container trees also need to be repotted on a semi-regular basis. For fast-growing varieties, this can be every year or two. With slow-growing trees, you may be able to go up to five years before repotting.
Best Trees for Containers in Ontario
The best trees to grow in pots should be small and relatively cold-hardy. Soil protects tree roots from the cold, so potted trees don’t have as much protection.
Native Ontario Small Trees
Dogwoods are one smaller native species that do well in containers. White flowers in spring and reddish branches can make an attractive addition to your space. Some dogwood varieties, like gray dogwood, can thrive in poor soil conditions.
Serviceberry is another hardy small native tree that thrives in Ontario. They’re disease-tolerant and grow slowly, meaning you won’t need to repot as often.
Dwarf coniferous trees are a popular choice. Not just for holiday decorating, these trees do well in containers year-round. They’re cold-hardy and slow-growing. Some popular varieties to try are fir, cypress, pine, hemlock, spruce, and juniper.
Adapted Trees
Japanese maples are another popular small tree for pots. They do well in sunny spots or those with a little shade.
Paperbark maple is another attractive maple variety that’s been gaining popularity. Like Japanese maples, they grow in full sun or partial shade.
Fruit Trees in Pots
Many fruit trees also grow well in containers.
Small cherry, plum, fig, and even apple varieties can be grown in containers in Ontario. Container fruit trees need regular pruning in their dormant season (late fall through winter). Plum trees are one of the easiest fruit tree varieties to grow in containers.
Some GTA gardeners even find success with citrus and tropical fruit trees. These will need to be brought indoors in fall and winter, or during cold snaps, however, they can provide a fun accent in the summer months.
Fruit trees, more so than other deciduous and coniferous trees, need regular pruning annually.
How to Plant Your Tree
Like other trees, spring and fall are the best seasons for planting container trees. You’ll need to pick a container that’s 30-40cm wider in diameter (12-16”) than your tree’s root ball.
When you pot the tree, pick a hardy potting soil. Lighter soils won’t provide sufficient nutrients for a whole tree. Fertilize your tree regularly during the spring and summer months. In Toronto and the GTA, it’s best to stop fertilizing around the beginning of September. That’s about 6 weeks before the average first frost date of October 13.
Getting Started
An arborist can help you select an appropriate container tree variety for your space and needs. They can also assist with planting and help you choose the right soil and container.
If you’re past your first year with your container tree, you may want to speak with an arborist about pruning your tree. This is especially beneficial for fruit trees, but for all container trees, you may need another type of pruning.
Root pruning can be used to maintain the size of a container tree’s root ball, avoiding the need for regular repotting. This job needs to be done carefully to avoid damaging the roots. It’s best to have a professional help — especially because this is a multi-person job for a tree of any notable size.
Have a bit more space and looking to plant a tree in the ground? Check out the best Trees for Small Yards
