Arborvitae Growing Guide: How to Pick, Plant, and Keep Thuja Green

Arborvitae is the default privacy hedge in American yards, and most of the time that default is the right call. The genus (Thuja) gives you a dense, year-round green wall that tolerates clay, shrugs off cold, and costs $30 to $60 a tree at the nursery. Plant a row, water it for two summers, and you’ll have a screen in five years. That’s the whole appeal.

But “arborvitae” isn’t one plant. It’s a genus with cultivars that range from a 3-foot globe to a 60-foot timber tree, and the single most expensive mistake homeowners make is buying the wrong one. If you want the cultivar-specific deep dives, we have full guides to Green Giant arborvitae and Emerald Green arborvitae. This guide is the overview that ties them together: how to pick between them, how to plant whatever you pick, and the honest problems every arborvitae shares.

Arborvitae at a glance

Almost every arborvitae sold at a garden center traces back to one of two species. Get the parentage straight and the rest of your decisions fall into place.

	American arborvitae (Thuja occidentalis)	Western / hybrid (Thuja plicata & ‘Green Giant’)
Mature size (species)	40-60 ft tall, 10-15 ft wide	50-70 ft tall, 15-25 ft wide
Growth rate	Slow (species); cultivars 6-12 in/yr	Medium to fast; ‘Green Giant’ 3-5 ft/yr
Zones	3-7	5-7 (Green Giant to 8b)
Native range	Eastern Canada into the Great Lakes and Appalachians	Alaska and the Pacific Northwest
Sun	Full sun best; tolerates part shade	Full sun; tolerates dappled shade
Deer	Heavily browsed	Species browsed; ‘Green Giant’ resistant

The size numbers come from the NC State Extension profile for Thuja occidentalis and the profile for Thuja plicata. Notice the species dimensions. That 40-foot number scares people who thought they were buying a hedge, and it should. The named cultivars are the ones bred down to hedge size, which is exactly why cultivar choice matters more than species.

The common name is worth knowing too. Sixteenth-century French explorers used the vitamin-C-rich foliage to treat scurvy, which earned it the Latin arborvitae, “tree of life.”

Who should plant arborvitae

Plant arborvitae if you want a living privacy screen and you’re in zones 3 through 8. Nothing else fills in a fence line faster for the money. A row of arborvitae blocks a neighbor’s second-story window, muffles road noise, and stays green in January when every deciduous screen is a stack of bare sticks.

It’s also forgiving. Arborvitae tolerates clay, handles a wide soil pH (6.0 to 8.0), and doesn’t need pruning to hold its shape. The pyramidal cultivars grow into a tidy cone on their own. For a full rundown of how it stacks up against the other quick screeners, see our roundup of fast-growing privacy trees.

Skip arborvitae if you have heavy deer pressure and don’t want to spray repellent all winter, or if your soil stays soggy after every rain. Both of those problems are covered below, because they’re the two that kill more arborvitae than anything else.

The honest catch

This is the section the nursery tag leaves off. Arborvitae is a good plant with five specific weak spots, and every one of them is avoidable if you know it’s coming.

Deer treat it like a salad bar. Thuja occidentalis is candy to white-tailed deer. NC State Extension puts it plainly: “Damage from deer browsing can be a serious problem.” In a bad winter, deer will strip an Emerald Green hedge to bare sticks from the ground up to six feet, and a crust of snow gives them a platform to reach higher. The frustrating part is that arborvitae won’t regrow from those stripped, bare stems (more on that under pruning). If deer walk your property, you’re either spraying repellent every month or you’re fencing. Bobbex Deer Repellent is the home-garden standard and it’s specifically rated for arborvitae. A quart of concentrate runs about $20 to $25 and covers a 50-foot hedge for a season. The cleaner fix is to plant a deer-resistant cultivar in the first place: ‘Green Giant’ inherits aromatic oils from its Western Red Cedar parent that deer mostly leave alone. Our guide to protecting trees from deer covers fencing and repellent rotation in detail.

Winter burn browns the sunny side. Arborvitae holds its foliage all winter, which means the foliage keeps losing water to sun and wind while the ground is frozen and the roots can’t refill it. The result is rust-brown foliage on the south, southwest, and west sides by February or March. It looks fatal and usually isn’t. Deep watering in October and November before the ground freezes is the single best prevention. For young trees in their first two winters, wrapping the trunk with Dewitt tree wrap shields the bark from winter sun and cold while the tree is still establishing.

Snow load splays multi-stem plants open. The narrow columnar cultivars, especially Emerald Green, are prone to flopping open under heavy wet snow or ice. Once the leaders splay outward, they don’t always spring back, and you’re left with a hedge that looks like an open hand. The fix is to tie the plant up before the first heavy storm: spiral jute twine from the base to the tip, or run a support stake for young trees. A tree stake and support kit handles the taller or newly planted specimens that a wrap of twine won’t hold. Sweep snow upward off the branches with a broom during a storm, never down, and never shake frozen branches because they snap.

Bagworms can defoliate a whole hedge. Bagworms are the most damaging insect pest arborvitae faces. The caterpillars build 1.5- to 2-inch cocoons out of the tree’s own foliage, so they blend right in until the browning starts. Each female bag holds hundreds of eggs for next year. Walk the hedge in winter and pick every bag off, and you knock next year’s population down by the same percentage you pick.

Inner browning fools everyone every fall. Every autumn, the oldest interior foliage on a healthy arborvitae turns bronze and drops. Homeowners panic and call an arborist. It’s normal needle shedding, the evergreen equivalent of a deciduous tree dropping leaves, and it clears on its own.

And the mistake that towers over all of these: planting ‘Green Giant’ as a small hedge. ‘Green Giant’ grows 3 to 5 feet a year to a mature 40 to 60 feet tall and 15-plus feet wide. People buy a cute 5-foot tree, plant a row 4 feet off the fence, and spend the next decade fighting it with loppers. If you want a hedge under 15 feet, you do not want ‘Green Giant.’ You want Emerald Green, ‘Techny’, or ‘North Pole.’ Match the cultivar to the space and you skip the whole fight.

Where arborvitae grows

Arborvitae is a cold-climate plant at heart. American arborvitae is hardy all the way to zone 3, which is why you see it hedging yards from Minnesota to Maine. The species range runs from eastern Canada through the Great Lakes and down the Appalachians. ‘Green Giant’ and its Western Red Cedar parent push warmer, into zone 8, but neither species loves real heat.

Here in Northern California I’ll be straight with you: arborvitae is not the slam dunk it is back East. Sacramento sits in zone 9b, past the comfortable range for both species. Emerald Green struggles here, growing slowly and picking up spider mites and fungal problems in the heat. ‘Green Giant’ does grow in the Central Valley, but at 2 to 3 feet a year instead of the advertised 4 to 5, and it wants a north or east exposure with afternoon shade and more water than the tag suggests. For hot inland yards, Italian cypress, Podocarpus, or Deodar cedar are smarter bets. Our columnar evergreen trees guide covers the California-friendly narrow options.

Planting arborvitae

The three things that make or break a planting are drainage, depth, and spacing. Get those right and the tree mostly raises itself.

Drainage first. Arborvitae roots rot in soggy soil, and root rot is the number one killer of established hedges. If your soil stays wet after a storm, plant on a mound 6 to 8 inches above grade and mix 30 percent coarse compost or pine bark fines into the backfill. On chronic wet sites, a French drain is cheaper than replacing a dead hedge in year four.

Depth second. The root flare, where the trunk widens into the roots, must sit at or slightly above the soil line. Nurseries pile extra soil around the trunk, so brush it away and find the flare before you dig. Set the tree with the flare 2 to 3 inches proud of grade. Planting too deep leads to crown rot and a slow death over two or three seasons. Dig the hole twice as wide as the root ball but no deeper than the ball is tall.

Spacing third, and it depends entirely on cultivar. This is where the cultivar guides earn their keep, but the short version:

• Emerald Green and other narrow cultivars: 3 to 4 feet apart for a solid hedge.
• ‘Green Giant’: 5 to 6 feet apart for a fast screen, and keep it at least 10 feet off any foundation or septic line.

Backfill with native soil, tamp to kill air pockets, water deeply, and lay 2 to 3 inches of mulch in a wide ring, kept 3 to 4 inches back from the trunk. Best planting time is fall (September to October) so roots establish before winter, with early spring a close second. Avoid summer.

Watering and care

New arborvitae needs consistent moisture, not daily sprinkling. For the first two weeks, water every other day with a soaker hose or drip line. Through the rest of the first growing season, water deeply once or twice a week. Skip the lawn sprinklers, which rarely soak the root zone, and use drip or a soaker instead.

Once established (year 3 and on), arborvitae wants about an inch of water a week from rain or irrigation. It tolerates short dry spells, but a long drought browns the interior and slows growth, and drought stress in late summer sets up a spider mite outbreak the following spring.

The one watering nobody wants to do is the one that matters most: the deep soak in late October and November before the ground freezes. Going into winter fully hydrated is the best defense against winter burn. Fertilizing is light. One application of a slow-release granular high in nitrogen in early spring, before new growth, is plenty. Stop by early summer, because late feeding pushes tender growth that frost will burn.

Pruning arborvitae

Here is the one pruning rule that matters more than all the others: never cut into bare wood. Arborvitae does not regenerate from old, leafless stems. If you cut back past the green foliage into brown branch, that spot stays bare forever. This is why deer damage and over-shearing are so unforgiving on this plant, and it’s the mistake that ruins more hedges than any pest.

Beyond that, arborvitae barely needs pruning. The pyramidal cultivars hold their cone shape on their own. If you’re shaping a hedge, shear lightly in late winter or early spring, staying in the green growth, and take no more than a third off in a season. You can slow a tall cultivar’s height by cutting back up to a third of the central leader in late winter, but you can’t permanently keep a 50-foot tree at 10 feet. Pick the right cultivar instead of pruning against its genetics.

Problems: pests, diseases, and browning

Six problems account for nearly every brown arborvitae: bagworms, spider mites, tip blight (Phomopsis and Kabatina), Phytophthora root rot, winter burn, and deer damage. Two are true diseases, the rest are pests or environmental stress, and from a distance they all look the same: brown patches on a declining hedge.

The single most useful diagnostic move is to scrape a “dead” branch with a fingernail. Green tissue underneath means the branch is alive and will recover. Brown all the way through means it’s dead and won’t come back.

I’m not going to re-run all six here, because we have a full diagnostic walkthrough that does exactly that. If your hedge is browning and you want to figure out which of the six you’re looking at, go straight to our arborvitae problems guide. It covers identification, cause, treatment, and prevention for each one, including the copper and Bt spray timings and the drainage fixes for root rot.

Cultivars worth knowing

The cultivar you pick determines almost everything about how this plant behaves in your yard. Here are the ones actually worth planting.

‘Green Giant’ (Thuja ‘Green Giant’) is the fast privacy screen. Three to five feet a year, 40 to 60 feet at maturity, deer resistant, and hardy to zone 8. It replaced Leyland cypress across the country after canker diseases wiped Leylands out. Plant it only where you have real room. Full details in our Green Giant arborvitae guide.

‘Emerald Green’ / ‘Smaragd’ (Thuja occidentalis ‘Smaragd’) is the tidy narrow hedge. It tops out around 12 to 15 feet and stays 3 to 4 feet wide, holds bright green color through winter, and needs almost no pruning. It’s slow (6 to 9 inches a year), deer love it, and it splays in heavy snow. The most-planted arborvitae in America for a reason. Our Emerald Green arborvitae guide has the full spacing and care breakdown.

‘Techny’ (Thuja occidentalis ‘Techny’, also sold as ‘Mission’) is the tougher, broader cousin of Emerald Green. It reaches 10 to 15 feet, holds a darker green through winter, and takes wind and cold better than most, which makes it a solid windbreak choice in zones 3 to 7.

‘North Pole’ is a narrow columnar cultivar similar to Emerald Green but a touch faster and more shade-tolerant, maturing around 10 to 15 feet tall and 3 to 5 feet wide. Also not deer resistant.

Globe forms (‘Hetz Midget’, ‘Little Giant’, ‘Danica’) are the rounded 2- to 4-foot dwarfs for foundation beds and borders, not screening. No shearing needed to hold the ball shape. Handy when you want arborvitae texture without a wall.

For the wider world of narrow upright evergreens beyond Thuja, see our columnar evergreen trees guide, and for how arborvitae fits into the broader picture of what to plant, our overview of common types of trees is a good starting point. If you’re weighing a hedge as a yard project, this landscaping investment guide has useful context on choosing trees for your region and getting value from the planting.

Frequently asked questions

How fast does arborvitae grow? It depends entirely on the cultivar. ‘Green Giant’ grows 3 to 5 feet a year, the fastest of the bunch. Emerald Green and most narrow Thuja occidentalis cultivars grow 6 to 12 inches a year. The species themselves are slow to medium. If speed is your priority, plant ‘Green Giant’ and give it room.

Do deer eat arborvitae? Yes, especially American arborvitae (Thuja occidentalis) cultivars like Emerald Green, which is one of deer’s favorite winter foods. ‘Green Giant’ is the exception; its Western Red Cedar parentage makes it deer resistant. In deer country, either plant ‘Green Giant’, spray repellent monthly from October through March, or install 8-foot fencing.

Why is my arborvitae turning brown? Six common causes: winter burn (brown on the sunny side after winter), spider mites (dusty bronze cast in spring), bagworms (brown bags hanging in the foliage), tip blight (dead shoot tips), root rot (whole branches yellowing from the bottom up), and deer damage (clean browse lines at 4 to 6 feet). Interior browning in fall is normal shedding. Our arborvitae problems guide walks through diagnosing each one.

Can I cut arborvitae back hard to make it shorter? No. Arborvitae won’t regrow from bare, leafless wood, so cutting past the green foliage leaves permanent bald spots. You can lightly shear the green growth and slow a leader’s height, but you can’t hard-prune a tall arborvitae down to a short one. Pick a cultivar sized for the space instead.

How far apart should I plant arborvitae? Cultivar-dependent. Space Emerald Green and other narrow cultivars 3 to 4 feet apart for a solid hedge. Space ‘Green Giant’ 5 to 6 feet apart, and keep it at least 10 feet from foundations and septic lines because it spreads 15-plus feet at the base.

Which arborvitae is best for a privacy screen? For a tall, fast screen on a large property, ‘Green Giant’. For a narrow, tidy hedge under 15 feet, Emerald Green or ‘Techny’. For a cold-climate windbreak, ‘Techny’. Match the mature size to your space before anything else, and compare the fast options in our fast-growing privacy trees roundup.