Arborvitae Growing Guide
Thuja spp.
Deer damage and winter bronzing get blamed on each other constantly, but they look different up close — bronzing fades leaf colour evenly, while deer strip whole branches bare, usually up to about 6 feet.
Light
Full sun to part shade; best density in full sun
Soil
Well-drained, moist; adaptable to many soil types
Water
Deep, regular watering for first 2 years, then moderate
Hardiness
Zones 2-8 depending on cultivar
Mature size
3-40 ft depending on cultivar; common hedge types 10-15 ft
Growth rate
Moderate — often 12-24 inches per year once established
Arborvitae is the go-to evergreen for privacy hedges across Canada thanks to its dense, narrow growth habit and cold tolerance, but newly planted trees are surprisingly vulnerable to both drought stress and deer browsing in their first few winters. Getting establishment watering and winter protection right in the early years makes the difference between a thin, patchy hedge and a solid one.
Planting
- Plant in spring or early fall to allow roots time to establish before summer heat or winter cold
- Space hedge plants according to mature spread of the cultivar — typically 3-4 ft apart for a dense privacy screen, closer for a faster-filling hedge
- Choose a site in full sun for the densest growth; part shade is tolerated but can produce a thinner, more open habit
- Amend heavy clay soil with compost at planting to improve drainage, since arborvitae dislikes standing water at the roots
Watering newly planted trees
- Water deeply once or twice weekly through the first two growing seasons, more often during hot, dry spells
- Continue watering right up until the ground freezes in fall — well-hydrated trees handle winter cold and wind far better than drought-stressed ones
- Established trees (3+ years) are more drought-tolerant but still benefit from deep watering during extended dry periods
- Mulch around the base (keeping mulch off the trunk itself) to retain soil moisture and moderate root temperature
Winter bronzing & deer protection
- Some winter bronzing (foliage turning yellowish-brown or orange) is a normal seasonal response to cold and sun, especially on exposed plants, and often greens up again in spring
- Water deeply in fall before freeze-up to reduce the severity of winter bronzing and desiccation
- Deer readily browse arborvitae in winter when other food is scarce — install physical fencing or burlap barriers around vulnerable plants, especially young ones, in areas with deer pressure
- Deer damage is typically height-limited (up to about 6 ft) and strips branches bare rather than just discolouring them, which distinguishes it from bronzing
- Repellent sprays can help but need reapplication through winter, especially after snow or rain
Pruning
- Shear or trim in late spring to midsummer to shape hedges while allowing time for new growth to harden before winter
- Avoid cutting back into old, bare wood — arborvitae generally does not regenerate new growth from leafless interior branches
- Remove dead, damaged, or crossing branches any time of year
- Maintain a slightly tapered shape (wider at the base) on hedges so lower branches still receive enough light
Common problems
- Winter bronzing: usually cosmetic and temporary, more severe in exposed, windy sites — improve fall watering and consider windbreak protection next season
- Deer browsing: strips foliage up to about 6 ft high, usually worse in winter — protect young trees with fencing or repellents in high-pressure areas
- Bagworms (small cone-shaped bags hanging from branches): hand-pick and destroy in early summer before larvae mature
- Brown, dying interior needles in fall: often normal seasonal needle drop for the previous year's growth, not necessarily disease
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Frequently asked questions
Bronzing discolours foliage evenly across the plant without removing it, and typically greens up again in spring. Deer damage strips branches of foliage entirely, usually up to about 6 feet high, and doesn't grow back on its own — it needs new growth to fill in.
More plant guides
- Ornamental Cherry Tree
Ornamental cherries are pruned far less than most people assume — heavy cuts invite the fungal disease black knot in through fresh wounds, so the best pruning plan is often the smallest one.
- Dahlia
In most of Canada, dahlia tubers won't survive winter in the ground — digging them up before the first hard frost isn't optional the way it is in milder climates.
- Coneflower
Deadheading coneflower all season actually costs you something — the seed heads left standing over winter feed finches and other birds and add structure to an otherwise bare garden.
- Dogwood
Red-twig dogwood's brilliant winter colour comes almost entirely from young stems — the brightest red or yellow wood is one to two years old, which is why hard, regular pruning actually improves the winter display instead of hurting it.