Short answer: Pick Green Giant if you have room and want the tallest, fastest screen. Pick Emerald Green arborvitae if you want a tidy, narrow hedge in a cold climate and deer are not a big problem. Pick Skyrocket juniper if your space is very tight, your soil is dry and you want the slimmest column you can get.
All three are among the best privacy trees you can plant, but they differ most in width, growth speed, deer appeal and snow tolerance. Here is how they compare.
The quick comparison
Heights and zones below come from our product listings. Widths come from university and arboretum references, because width is the number that decides your spacing and whether a tree fits your yard.
| Thuja Green Giant | Emerald Green Arborvitae | Skyrocket Juniper | |
|---|---|---|---|
| Plant type | Hybrid arborvitae | American arborvitae | Upright juniper |
| Growth rate | Fast (3 to 4 feet a year when young) | Moderate | Fast |
| Mature height | 30 to 50 feet | 10 to 15 feet | 12 to 15 feet |
| Mature width | 12 to 20 feet | 3 to 5 feet | 2 to 3 feet |
| Hardiness zones | 5 to 8 | 3 to 8 | 4 to 9 |
| Sun | Full sun to part sun | Full sun (thins in heavy shade) | Full sun best |
| Spacing for a hedge | 5 to 6 feet | About 3 feet | 2 to 3 feet |
| Deer | Generally resistant | Often eaten | Seldom badly damaged |
| Heavy snow | Holds up well | Can splay open; may need tying | Can splay; tie in snowy areas |
A quick note on zones: a USDA hardiness zone is a number based on the coldest average winter temperature where you live. Lower numbers are colder. If a tree is rated for zones 5 to 8, it should survive winters in those areas. Not sure of yours? Use our growing zone guide.
Thuja Green Giant: the fastest, biggest screen
The Thuja Green Giant is a hybrid arborvitae. According to the U.S. National Arboretum, a single plant arrived from a Danish nursery in 1967, and the Arboretum later introduced it as a substitute for Leyland cypress. It describes the tree as rapid-growing, reaching about 30 feet in 30 years and eventually up to 60 feet, with a spread of 12 to 20 feet.
University of Arkansas Extension notes that young trees can add three or four feet of growth a year, and that Green Giant has good drought tolerance once established. NC State Extension adds that it "resists most diseases, insects, periodic droughts, and deer," though bagworms can occasionally show up and roots can rot in soggy soil.
The catch: it gets wide
Green Giant is not a skinny tree. NC State Extension warns that, like Leyland cypress, it "can quickly grow very large and become a problem if planted in a space that is inadequate for the tree's full size." Arkansas Extension also points out that it cannot be cut back hard once it outgrows its spot. If you only have a narrow strip between a driveway and a fence, it is the wrong pick.
Best for: big yards, long property lines, blocking a two-story house next door, and windbreaks. Give it full sun to light afternoon shade and well-drained soil. NC State notes it does not tolerate salt spray.
Emerald Green Arborvitae: the tidy, narrow hedge
Emerald Green Arborvitae (botanical name Thuja occidentalis 'Smaragd') is the classic narrow hedge plant. The Purdue Arboretum lists it at 10 to 15 feet tall and only 3 to 4 feet wide, and the University of Connecticut Plant Database gives about 15 feet tall by 5 feet wide. UConn also notes it holds its bright green color well through winter and has excellent cold and heat tolerance.
The Chicago Botanic Garden calls it "a great, hardy, maintenance-free living fence." It does best in full sun. The Chicago Botanic Garden warns that too much shade gives it a loose, thin look.
Two weak spots: deer and snow
American arborvitae is a deer favorite. UConn calls it "a favorite food of deer," and Cornell Cooperative Extension lists American arborvitae among woody plants frequently severely damaged by deer. Iowa State University Extension notes that deer often feed on the lower branches of arborvitae when food is scarce.
Snow is the other issue. UConn says heavy snow often causes damage to this species. The Chicago Botanic Garden suggests brushing heavy snow off with a broom so branches do not bend too far, and Iowa State Extension recommends wrapping arborvitae loosely with twine or rope in fall, then removing it promptly in spring.
Best for: formal hedges, small yards, cold climates down to zone 3, and spots where you want a 10- to 15-foot wall without a 15-foot-wide tree. Plan on deer protection if deer visit your yard.
Skyrocket Juniper: the narrowest option
Skyrocket Juniper is one of the slimmest upright evergreens you can plant. The Purdue Arboretum describes its "extremely narrow" form at about 15 feet tall and 2 feet wide, and Texas Tech University lists it at 2 to 3 feet wide. Texas Tech notes it can reach 20 to 30 feet over many years, so treat the listed height as a long-term range rather than a ceiling.
It is usually sold as a Rocky Mountain juniper (Juniperus scopulorum), though Oregon State University notes that some botanists now classify Skyrocket as a form of eastern redcedar. Either way, it is a dry-climate juniper. Purdue calls it drought-tolerant and pollution-resistant, happy in alkaline soil, but unable to tolerate wet soils. Texas Tech says it will not withstand the humidity and heat of the deep South.
Deer and snow
Junipers are generally less appealing to deer than arborvitae. Cornell Cooperative Extension lists juniper (Chinese juniper) among woody plants seldom severely damaged by deer, and an Extension expert answer on Ask Extension notes deer do not prefer junipers because of their scent, while cautioning that hungry deer will try almost anything. Like other multi-stemmed evergreens, Skyrocket can be pulled open by heavy, wet snow, so the twine wrap that Iowa State recommends is a good idea in snowy areas.
Best for: tight side yards, corners of a house, along walkways, and dry, sunny spots with good drainage. Because each plant is so narrow, you will need more of them per foot of fence line than any arborvitae.
Spacing: how many trees you need
For a solid screen, space privacy trees a bit closer than their mature width so neighbors grow together. For these three, that works out to:
- Green Giant: 5 to 6 feet apart for a solid screen, up to 8 feet if you can wait longer for it to fill in.
- Emerald Green: about 3 feet apart for a continuous hedge.
- Skyrocket: 2 to 3 feet apart. Plant at 2 feet if you want a solid wall sooner.
For a 60-foot property line, that is about 10 to 12 Green Giants, about 20 Emerald Greens or about 20 to 30 Skyrockets. Our guide on how far apart to plant arborvitae privacy trees walks through the math in more detail.
Which one should you pick?
"I want privacy as fast as possible and I have room."
Go with Thuja Green Giant. Nothing in this lineup grows taller faster. Leave at least 6 to 10 feet between the trunk line and a fence or building so it has room to spread.
"I want Green Giant's speed but not its size."
Look at the Junior Giant Thuja Tree, a smaller fast-growing thuja listed at 15 to 20 feet tall and 12 to 15 feet wide for zones 6 to 9. It is still wide, but far easier to fit than a 40-foot tree.
"I live somewhere very cold."
Emerald Green Arborvitae is rated to zone 3. Another option is Private Jet™ Arborvitae, listed for zones 3 to 7 at 15 to 20 feet tall and 4 to 5 feet wide with a fast growth rate, which makes it a taller narrow choice for cold climates.
"Deer eat everything in my yard."
Skip Emerald Green unless you are ready to fence or spray. Green Giant (which NC State Extension describes as resisting deer) or a juniper like Skyrocket or Spartan Juniper are better bets. Spartan is listed at 15 to 20 feet tall and 3 to 5 feet wide for zones 5 to 9, so it is a bit fuller than Skyrocket.
"I have a narrow side yard or a 4-foot planting strip."
Choose Skyrocket for the narrowest fit. If you prefer a softer, bluish-green column with a bit more body, the Moonglow Juniper Tree is listed at 15 to 20 feet tall and 4 to 6 feet wide. For an even smaller space, such as beside an entry or patio, Sky Pencil Holly stays far shorter and works well in part sun.
"My soil stays wet, or my summers are hot and humid."
Avoid Skyrocket. Purdue notes it cannot tolerate wet soils, and Texas Tech says it struggles in deep-South heat and humidity. Green Giant grows in soils from sandy loams to heavy clays, according to the U.S. National Arboretum, though NC State Extension notes it needs good drainage.
Want to see a few more options before you decide? Our roundup of fast-growing evergreens that actually make a privacy screen covers more choices.
Common questions
Which grows faster, Green Giant or Emerald Green arborvitae?
Green Giant, by a wide margin. University of Arkansas Extension says young Green Giants can add three to four feet a year, while Emerald Green is a moderate grower.
Is Skyrocket juniper a good privacy tree?
Yes, for narrow spaces in sunny, well-drained spots. Because it is only 2 to 3 feet wide, plant it 2 to 3 feet apart so the trees grow together into a wall.
Do deer eat Green Giant arborvitae?
NC State Extension says Green Giant resists deer, which is a big reason people choose it over American arborvitae. Young trees can still get nibbled when food is scarce, so watch new plantings their first winter.
How do I keep arborvitae from splitting in snow?
Iowa State University Extension recommends wrapping plants loosely with twine or rope in fall and removing it in spring. Brushing off heavy snow after a storm, as the Chicago Botanic Garden suggests, also helps.
Find your privacy tree
Whether you need a 40-foot wall or a slim column for a side yard, browse our full lineup of privacy trees and compare heights, widths and zones in one place.
Sources and further reading
- Thuja 'Green Giant', U.S. National Arboretum (USDA Agricultural Research Service)
- Thuja 'Green Giant', NC State Extension Gardener Plant Toolbox
- Plant of the Week: Green Giant Arborvitae, University of Arkansas Cooperative Extension Service
- Thuja occidentalis 'Smaragd', Purdue Arboretum
- Thuja occidentalis (Arborvitae), University of Connecticut Plant Database
- Thuja occidentalis 'Smaragd', Chicago Botanic Garden
- Juniperus scopulorum 'Skyrocket', Purdue Arboretum
- Skyrocket Juniper, Texas Tech University
- Juniperus scopulorum, Oregon State University Landscape Plants
- Deer Resistant Plants, Cornell Cooperative Extension of Columbia and Greene Counties
- Are juniper species resistant to deer damage?, Ask Extension
- Protecting Trees and Shrubs in Winter, Iowa State University Extension and Outreach
