If you are shopping for a fast-growing privacy tree, you have probably narrowed your list to two heavy hitters: Green Giant Arborvitae (Thuja standishii x plicata 'Green Giant') and Leyland Cypress (x Cupressocyparis leylandii). Both grow fast, stay green year-round, and can form a dense screen in just a few years.
But they are not interchangeable. One is significantly more disease resistant, longer lived, and lower maintenance than the other. Here is an honest, side-by-side comparison based on real growing data so you can pick the right tree for your yard, your zone, and your long-term goals.
Quick Comparison: Green Giant vs Leyland Cypress at a Glance
| Feature | Green Giant Arborvitae | Leyland Cypress |
|---|---|---|
| Growth Rate | 3-5 ft/year | 3-4 ft/year |
| Mature Height | 40-60 ft | 50-70 ft |
| Mature Width | 12-18 ft | 10-15 ft |
| Hardiness Zones | 5-8 | 6-10 |
| Disease Resistance | High (hybrid vigor) | Low (prone to incurable canker and root rot) |
| Deer Resistant | Yes | Moderate |
| Drought Tolerance | High (once established) | Moderate |
| Salt Tolerance | Poor | Good (coastal areas) |
| Lifespan | 40-60 years | 20-50 years |
| Maintenance | Low (rarely needs pruning) | High (regular pruning required) |
| Privacy Screen Spacing | 5-6 ft apart | 8-10 ft apart |
| Root System | Deep taproot, stable | Shallow roots, can topple |
How Fast Do Green Giant Arborvitae and Leyland Cypress Grow?
Both trees are among the fastest-growing evergreens available. Green Giant Arborvitae typically adds 3 to 5 feet per year once established, making it one of the fastest privacy trees on the market. Leyland Cypress grows at a similar pace of 3 to 4 feet per year in early years.
The difference shows up over time. Green Giant maintains its dense, pyramidal form with minimal effort, while Leyland Cypress requires regular pruning to keep a tidy shape. Without pruning, Leyland Cypress can become open and leggy.
Both trees follow the "Sleep, Creep, Leap" rule: the first year they establish roots (sleep), the second year they put on moderate growth (creep), and the third year they take off (leap). Deep watering during that first year is critical for both species.
Which Has Better Disease Resistance?
This is where the comparison tilts heavily in favor of Green Giant Arborvitae.
Green Giant Arborvitae benefits from hybrid vigor (it is a cross between Japanese Arborvitae and Western Red Cedar). According to NC State Extension, "it resists most diseases, insects, periodic droughts, and deer." Occasional bagworms are the primary concern, and those are manageable with early detection.
Leyland Cypress has serious, well-documented disease problems. NC State Extension flags it as "problematic" and notes that it "is severely pest- and disease-prone." The two biggest threats are:
- Seiridium and Botryosphaeria canker — fungal infections that cause branch dieback and are typically incurable, especially after drought stress
- Phytophthora and Armillaria root rot — soil-borne diseases that kill the root system and are also incurable
These are not minor issues. In the southeastern United States, where Leyland Cypress was once the default privacy tree, canker has killed thousands of mature specimens. Many extension services now recommend Green Giant as the replacement.
What Zones Do They Grow In?
Green Giant Arborvitae thrives in USDA zones 5 through 8. It handles cold winters well (down to -20 degrees F) and tolerates summer heat in zones 7 and 8 without the disease problems that plague Leyland Cypress in the same areas.
Leyland Cypress prefers zones 6 through 10. It handles warmer climates but is poorly adapted to areas with hot, dry summers (according to NC State Extension). It performs best in coastal regions with high humidity, where its salt tolerance is a genuine advantage.
Bottom line: If you are in zones 5 or 6, Green Giant is the clear choice. If you are in zones 7 or 8, Green Giant is still the better option due to its disease resistance. Leyland Cypress only has an edge in zone 9 or 10 or in coastal areas where salt spray is a factor.
How Far Apart Should You Plant Them?
Green Giant Arborvitae should be planted 5 to 6 feet apart (center to center) for a privacy screen. The lower branches interlock naturally within 3 to 4 years, forming a solid wall of green without any shearing.
Leyland Cypress needs wider spacing at 8 to 10 feet apart. This means you need fewer trees to cover the same distance, but the screen takes longer to fill in.
For a windbreak (where full density is less important), Green Giant can be spaced 8 to 12 feet apart, and Leyland Cypress 12 to 15 feet apart.
Which Is Lower Maintenance?
Green Giant Arborvitae rarely needs pruning. It maintains a naturally dense, pyramidal shape on its own. Light trimming in early spring or mid-summer can control height if needed, but many gardeners never prune their Green Giants at all.
Leyland Cypress requires regular pruning to maintain a tidy appearance. NC State Extension specifically notes it "must be pruned regularly." It does take well to severe pruning and shearing, which makes it suitable for formal hedges if you are willing to put in the work.
| Task | Green Giant | Leyland Cypress |
|---|---|---|
| Watering (Year 1) | Deep weekly watering | Deep weekly watering to 12-18 inches |
| Pruning | Rarely needed | Regular pruning required |
| Fertilizing | Slow-release in early spring | Slow-release in early spring |
| Disease monitoring | Occasional bagworm check | Monitor for canker, root rot, bagworms, spider mites |
| Winter care | None (may bronze slightly, returns to green in spring) | Mulch to protect shallow roots |
Which Is More Deer Resistant?
Green Giant Arborvitae is significantly deer resistant. The foliage is less palatable to deer than other arborvitae varieties, making it a reliable choice in areas with heavy deer pressure.
Leyland Cypress has moderate deer resistance. It is not a preferred browse, but deer may sample it in late winter when food is scarce.
If deer are a major concern in your area, Green Giant is the safer bet.
What About Root Stability?
Green Giant Arborvitae develops a deep taproot that anchors the tree well. Mature specimens stand up to wind, snow loads, and storms.
Leyland Cypress has a shallow root system. NC State Extension notes that "large specimens tend to topple over." This is a real concern in areas with high winds or saturated soils, especially as trees reach 40 feet and taller.
When Should You Choose Leyland Cypress Instead?
Leyland Cypress does have genuine advantages in specific situations:
- Coastal properties with salt spray — Leyland Cypress tolerates salt well; Green Giant does not.
- Zones 9 and 10 — Green Giant is not recommended above zone 8. Leyland Cypress handles warmer climates.
- Formal, sheared hedges — If you want a tightly clipped hedge and are willing to maintain it, Leyland Cypress takes to heavy shearing better.
- Very fast initial screening — In zones where both trees grow well, Leyland Cypress can reach screening height slightly faster due to its narrower form, though the difference is modest.
Our Recommendation
For most gardeners in zones 5 through 8 who want a fast-growing, low-maintenance privacy screen, Green Giant Arborvitae is the better choice. It grows just as fast (often faster), resists disease, tolerates deer and drought, needs almost no pruning, and lives decades longer.
Green Giant has become the go-to replacement for Leyland Cypress across the Southeast and Mid-Atlantic for good reason. It delivers the same screening performance with far fewer problems.
Choose Leyland Cypress only if you are in a coastal zone 9 or 10 area where salt tolerance is essential, or if you specifically want a heavily sheared formal hedge.
Related Reading
- Emerald Green vs Green Giant Arborvitae: Which Is Right for Your Yard?
- How Much Do Privacy Trees Cost? Size and Spacing Guide
- Best Deer Resistant Shrubs That Actually Work
Watch: Privacy Trees and Deer Resistant Picks
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Ready to plant your privacy screen? Shop our Green Giant Arborvitae and browse our full Privacy Trees collection for more options sized for your yard and zone.
