How far apart should I plant a cedar hedge in Ontario?

For emerald cedars, plant 2 to 3 feet apart, measured from main stem to main stem. About 2.5 feet gives the fastest solid hedge with only small starting gaps, 3 feet still forms a continuous screen at maturity but starts with larger gaps, and 4 feet leaves the trees looking like separate specimens that never fully touch. Larger species cedars like eastern white cedar need more room, since they mature much wider.

How much water does a new cedar hedge need?

A lot, for the first two years. Water deeply and regularly through the growing season and keep watering right up until the ground freezes in fall, since cedars lose moisture through their foliage all winter. A thick mulch ring at the base holds that moisture in. Under-watering, especially before freeze-up, is the most common reason a young cedar hedge browns or dies over its first Ontario winter.

When is the best time to plant a cedar hedge?

Spring and fall are both good planting windows in Ontario. Fall planting lets roots establish in soil that still holds summer warmth, while spring gives the hedge a full first season, as long as you water through summer. Avoid planting into peak summer heat or frozen winter ground. Whichever window you choose, water deeply from planting onward and mulch to lock in moisture.

How do I stop my cedar hedge from getting winter burn?

Winter burn, the browning of foliage over winter, comes mostly from cedars drying out. Prevent it by watering deeply until the ground freezes in late fall, mulching to retain moisture, and, where possible, planting in a spot sheltered from harsh winter wind. For a young or exposed hedge, a burlap screen or an anti-desiccant spray through the first winter helps. Road salt spray also browns cedars, so keep them back from salted driveways and sidewalks.

When should I trim a cedar hedge in Ontario?

Late June to early August is the reliable window. By then the spring flush has firmed up so the shape holds, and there is still time for the cut tips to harden before frost. Avoid heavy cuts in late summer, fall, or winter, which invite winter burn or damage a dormant plant. Because the trimming window overlaps bird nesting season, check the hedge for an active nest first, which is required under the Migratory Birds Convention Act.

How tall does an emerald cedar hedge get?

Left alone, an emerald cedar reaches about 15 to 20 feet tall while staying only about 3 to 4 feet wide, which is what makes it ideal for narrow lots. Most homeowners keep a hedge trimmed to 5 to 8 feet for easy maintenance and a dense, formal look. Regular light trimming keeps it fuller and at a height you can actually reach and manage.

Cedar Hedges in Ontario: Planting, Spacing & Care

Answer First: For a dense Ontario cedar hedge, space emerald cedars 2 to 3 feet apart, plant in spring or fall, and water deeply for the first two years, right up until the ground freezes, with a thick mulch ring to hold moisture. Trim once a year in the late-June-to-early-August window, checking for active bird nests first. Get spacing and watering right and the hedge knits into a solid green wall; get them wrong and it browns or gaps.

A cedar hedge is the most planted privacy screen in the GTA and the most commonly botched. The trees are cheap and forgiving enough that people plant them too far apart, forget to water them, and then wonder why they have a row of thin brown cones instead of a wall. The fixes are simple and they are all decided in the first two years. Here is the whole playbook.

How far apart should you space a cedar hedge?

For emerald cedars, 2 to 3 feet apart, main stem to main stem. This single decision sets whether you get a solid hedge or a row of separate trees, so it is worth getting right before the shovels come out.

Spacing diagram of emerald cedars showing 2.5 feet fills in fast, 3 feet touches at maturity, and 4 feet leaves permanent gaps between separate trees — Spacing decides the wall. About 2.5 feet fills in fastest, 3 feet closes at maturity, and 4 feet leaves the cedars as separate specimens that never fully touch.

Closer spacing fills in sooner but costs more per foot of hedge because you buy more trees. The three common choices break down cleanly:

About 2.5 feet: the fastest route to a solid screen, with only small gaps at the start that close quickly.
3 feet: still forms a continuous hedge at maturity, but starts with larger visible gaps you wait out.
4 feet or more: the trees read as separate specimens and never fully touch, so this is spacing for a row of cedars, not a hedge.

Larger species like eastern white cedar mature much wider, up to 7 to 10 feet across, so they need proportionally more space than the narrow emerald cultivar. If you want the fuller picture on choosing between them and other screens, see our guide to fast-growing privacy trees and hedges for the GTA.

Quotable: Space emerald cedars 2 to 3 feet apart for a hedge: about 2.5 feet fills in fastest, 3 feet still closes at maturity, and 4 feet leaves permanent gaps. Spacing, not fertilizer, is what makes a cedar hedge solid.

When and how should you plant a cedar hedge?

Plant in spring or fall, set each tree at the right depth, and mulch. The GTA's two planting windows, late April to June and early September to late October, both work for cedars; skip the peak of summer heat and frozen ground. Our tree-planting timing guide covers the windows in detail.

Cross-section of a correctly planted cedar showing the root flare at ground level, a hole wider than the root ball, native backfill, and a mulch ring kept off the trunk — Plant each cedar wide, not deep. The root flare sits at grade, the hole is wider than the root ball, and mulch forms a ring that never touches the trunk.

Dig a hole wider than the root ball, no deeper. Set the tree so its root flare, where the trunk widens into the roots, sits right at ground level. Planting too deep is a slow killer.
Backfill with native soil and firm gently. Remove air pockets. There is no need for rich amended soil in the hole.
Mulch in a ring, not against the trunk. Spread a thick layer of mulch over the root zone, pulled back a few centimetres from each stem, to hold moisture and suppress weeds.
Water in deeply at planting. Give the whole row a long soak the day you plant, and then keep it up, which is the next section.

How do you keep a cedar hedge alive and green?

Water and moisture, especially before winter. Cedars lose water through their foliage all year, including through a dry, windy Ontario winter, so a hedge that goes into freeze-up thirsty is the one that browns by March.

Winter burn, the browning or scorching of evergreen foliage over winter, caused mostly by the plant losing moisture faster than its frozen roots can replace it. It looks like frost damage but is really drought, which is why watering before freeze-up prevents it.

Give a new hedge deep, regular watering for its first two years, right up until the ground freezes in late fall, and keep the mulch ring topped up to hold that moisture. Where you can, plant in a spot sheltered from the harshest winter wind, and for a young or exposed hedge, a burlap screen or an anti-desiccant spray through the first winter buys insurance against burn. One more Toronto-specific hazard: road salt spray browns cedars badly, so keep the hedge back from salted driveways and sidewalks.

From the data: YardQuote tracks 650 landscaping companies across the GTA, and a supplied-and-planted cedar runs about $150 to $500 per tree depending on size, with crew labour at $50 to $100 an hour (YardQuote cost data, July 2026). A full fence-line hedge is a real project, so the cheapest insurance on that spend is correct spacing and two years of honest watering.

Trimming a cedar hedge without breaking the law

Trim once a year in late June to early August, and check for nests first. By late summer the spring growth has firmed up so the cut holds its shape, and there is still time for the tips to harden before frost. A hard cut in fall or winter invites winter burn or damages the dormant plant.

The catch is that the ideal trimming window overlaps bird nesting season, and under the Migratory Birds Convention Act it is a federal offence to disturb an active nest. Before you cut, walk the hedge and look for a nest or for birds flying in and out of one spot; if you find an active nest, wait a few weeks until the young fledge. Our full guide on when to trim hedges in Ontario covers the timing and the nest check in detail. For a tall hedge or a full reshape, a rated crew is worth it, you can check landscaping costs and browse pros on the landscaping directory for your area.

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