Trees in the Glebe:

The 40-year old chestnut in Paul Durber’s back yard has been pruned to admit sunlight so its shape is almost elm-like. Photo: Kieran Humphries
The 40-year old chestnut in Paul Durber’s back yard has been pruned to admit sunlight so its shape is almost elm-like.
Photo: Kieran Humphries

Prepare to plant

by Jennifer Humphries

This column is dedicated to tree-planting neophytes and those who don’t have a green thumb but are keen to get planting in 2017. It will also be of interest to experienced tree-planters.

Get your tree

Ecology Ottawa, which is partnering with the Glebe Community Association (GCA) on our Trees in the Glebe initiative, is a community-driven, citywide not-for-profit organization. Ecology Ottawa will begin in April to give city residents 10,000 seedlings that they have been able to purchase through grants. The tiny trees will be made available at events including the Old Home Earth Day Event on Saturday, April 22 at the Glebe Community Centre. The selection comprises four deciduous species (two types of maple, white birch, yellow birch) and five coniferous species (eastern white pine, which is Ontario’s official tree, red pine, white cedar, white spruce and Colorado spruce). If you can’t make it to the Old Home Earth Day Event, check Ecology Ottawa’s website and get on the mailing list for other opportunities.

Crabapples in winter Photo: Kieran Humphries
Crabapples in winter
Photo: Kieran Humphries

Velta Tomsons of Ecology Ottawa points out that their sesquicentennial tree project goes back to 2013 when the organization launched a campaign to encourage the planting of a million trees in the city as a 150th birthday gift to Canada. “Trees and parks are the only infrastructure that get better over time,” says Tomsons. A million trees is a tall order, but the City of Ottawa has already committed to planting 125,000 trees a year for four years. Still, that gets us only halfway to the goal so Ecology Ottawa is urging tree planting on both public and private lands.

Another opportunity to buy trees is at the Friends of the Farm plant sale taking place this year on Sunday, May 14. The Friends offers workshops on a range of gardening topics and also offers Arboretum tree tours with expert guides; the first of the 2017 tours is on Sunday, May 7. Visit the Events page at The volunteer group Master Gardeners of Ottawa-Carleton also offers gardening workshops (

Planting 101

Sarah Johnston, president of Greenlife Wholesale Nursery and Greenlife Garden Care & Landscaping, kindly answered my questions on “planting for success.”

JH: What are the most important factors in successful tree planting?

SJ: First of all, know your location: soil, light exposure, obstructions. Much of Ottawa’s soil is clay-based and that will guide tree selection. Alkalinity and acidity are more important for coniferous trees than deciduous. You can get a kit to test alkalinity/acidity but reputable nurseries know what will work well in a specific area.

In terms of light, whether your tree is in a north or south yard is less important than what it is located next to. If you put a cedar beside an established one, it will be brown on the shaded side and green on the sunny side.

It’s not advisable to plant directly under electrical wires. Service suppliers don’t have the same concern for your tree as you do and trimming may leave you with a misshapen tree. And the prevalence of ice storms in Ottawa makes trees located below wires extremely vulnerable.

As to how to plant a container tree, which is how small saplings will come to you, I recommend “planting it proud.” This means you leave the top quarter of the root ball above the soil then add soil up to the root base to cover it and slope down to the surrounding ground. The reason for this is that once you dig a hole in clay soil you create a well. Water doesn’t dissipate and the newly planted tree can drown. By keeping the fine roots closer to the surface and sloping the soil you create the ideal conditions for the roots to anchor in to the top quarter and spread out. It’s also a good idea to circle your tree with mulch to keep the soil moist but not soggy. Don’t take off the soil when you remove your new tree from the container or pot – plant all the soil with the tree and don’t disturb the roots.

If you are staking your young tree to give it extra support, always stake on the northwest, prevailing wind side.

If you have a larger tree – bigger than a 4 to 5 foot container tree – it will have a larger root ball that comes in a wire basket with burlap. The basket is not restrictive to the tree and you do not want to disturb the root base. Once the root ball is positioned in the hole, the top of the wire basket should be cut and 1/3 folded back into the hole along with the top 1/3 of the burlap.

JH: What about watering?

SJ: Trees are ideally planted in the spring and fall. There is sufficient natural water in those times. If you do have to water, do so three feet away from the trunk, not directly at the root of the tree and water down. And don’t fill that clay “well” with water.

JH: Are spring and autumn equally good?

SJ: Fall is ideal, spring is good. We generally plant until the second week of November. The ground is not frozen so there is still a water system that the tree can use. You can plant in the spring as soon as the ground is thawed. Tree availability is limited at nurseries in April, though. There are more trees in May.

JH: So what can go wrong?

SJ: People love trimming the edges of their lawns with whipper snippers and sometimes damage tree bark in doing so. Keep a respectful circle around your tree equal to the umbrella width of the tree.

JH: Are there times when it is better to have a professional plant your tree?

SJ: It depends on the investment you are making in the tree. If you choose a gingko, popular with both the City of Ottawa and homeowners, it will cost more than other trees because it is slow-growing and so takes more time to get to a saleable height. If you are uncomfortable with planting, get a professional horticulturalist, and make sure that they provide a one-year warranty on the tree. We do this and if someone is concerned about their tree, we ask them to send us a photo so we can determine what is needed, including looking at the tree onsite.

Please help Trees in the Glebe track our progress by registering your new tree or suggested space on public or private property at:

Jennifer Humphries is a member of the Glebe Community Association’s Environment Committee, which, in cooperation with Ecology Ottawa, is promoting the planting of 150 or more new trees in the neighbourhood in 2017. Write to Jennifer at

Share this