Leyland Cypress vs Green Giant Arborvitae | What’s The Difference

Looking to plant a new privacy barrier around your property? Or, maybe a few sturdy trees to create a more formal theme in your landscape? With all the potential options out there, where do you start? 

Nothing is more beautiful or cost-effective when it comes to creating protective barriers and statement plantings than two particular evergreens. The question is, is one better than the other?

Weighing the benefits of a Leyland Cypress vs Green Giant Arborvitae is as simple as understanding which one best fits your planting area and hardiness zone.

Leyland Cypress vs Green Giant: Similar But Different 

The genetic and geographical backgrounds of these fast-growing trees don’t necessarily make one a better choice than the other. But, they may speak to how well each will perform where you plan to plant it.

The Leyland cypress is the result of random, organic, cross-pollination between a Nootka cypress (from Alaska) and a Monterey cypress (from California), when each was shipped to the UK, by a botanist, and planted together.

The Thuja Green Giant is a cross between a Western Red Cedar and a Japanese Arborvitae and also resulted from cross-pollination. 

The greatest benefit of organically occurring hybrids, for you, is that they grow faster and are much more resistant to pests and disease than their “parents”. 

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How To Tell Them Apart 

While these two hybrids are fairly similar, there are some distinct differences. Both grow in a sturdy, conical shape. Yet, the Green Giant can reach a full 30ft taller, and 6ft wider, than a Leyland cypress. 

The Leyland displays elegant, evergreen branches, laced with sprays of blue-green needles and small berries. While emitting a spicy, woody scent.

The Green Giant is a conifer that presents soft, “braided” fronds of deep green and a denser growing habit than the Leyland. To include seasonal cones rather than flowers or fruit. All exuding a subtle, musky fragrance that naturally repels pests. 

Leyland Cypress
Leyland Cypress
Thuja Green Giant Tree
Thuja Green Giant

Growth Rate and Natural Habitat 

The growth rate and natural hardiness zone of each of these are key to which would better suit your landscape. 

The Green Giant can grow to a mature size of 100ft by 20ft, at a rate of 4ft per year, in optimal conditions. These conifers thrive in the foothills of hardiness zones 6-8, where they’re hardy down to -10°F (-23°C).

The Leyland cypress matures to a slightly smaller 70ft by 15ft, at a slower 3ft per year. This is also better adapted to warmer climates, often seen growing in large swathes across zones 6-10. 


For year-round color and fast growth for privacy hedges, both the Thuja Green Giant and Leyland Cypress are obvious choices.

Functionally, these trees can protect homes against harsh winds and other severe weather conditions. 

Visually, they perform well as tall feature plantings, around entryways, and in formal gardens and can be pruned down to fit just about any height requirement. 

If you have one that’s reached the end of its life cycle, chipped Cypress and Arborvitae wood also makes fantastic mulch, as winter protection, around perennial flowers and shrubs, in cold climates. 

Care Guide 

As a result of being organic hybrids, Leylands, and Green giants are tough, relatively cold hardy, and can adapt to a variety of soil types.

However, in their natural habitat, they are used to receiving consistent water and nutrients through the highly-efficient, organic processes of their immediate environment. 

Have you ever seen the Cascade Mountains in the Pacific Northwest region of the US? Miles and miles of lush evergreens and conifers have been nourished solely by their surroundings. 

Despite their adaptability to poor soil, without proper care, the branches of these trees may become bare and color may fade.

Leylands and Green Thujas are fairly low-maintenance but they do need a few considerations, with small differences between them. 

Position & Light Requirements 

Matching one of these majestic evergreens to your hardiness zone should be your first consideration. The second should be matching their light requirements to your intended planting location. 

Green giants grow best in partial sun and shade, especially if you live in a warmer climate, while the Leyland thrives in full sun. 

Both should be positioned 6-8ft away from your home and a minimum of 6ft from each other, in a privacy hedge. 

Temperature And Humidity 

This is where these two trees really differ. While both have adapted to similar hardiness zones, one loves the cold and moist soil and the other is tolerant of heat and drought. 

Recommended for zones 5-9, the Green Giant Arborvitae performs best in zones 5, 6, and 7. Easily tolerating temperatures down to -20°F. Leylands are recommended for zones 6-10 and can withstand -10F temps, yet thrive in zones 8, 9, and 10. 


Both hybrids perform best in fertile, well-draining soil. The Green Giant prefers consistently moist soil. During periods of dry weather, additional watering will prevent browning.

The Leyland prefers to dry out a bit, in between waterings and is better equipped to handle periods of drought.

Leylands are quite tolerant of sandy, salty soils that are common in coastal areas. But, Thujas are sensitive to high salinity and favor a lower soil pH, as well. 

Planting Considerations 

Avoid planting these trees against your home or other structure. Their roots don’t necessarily pose a threat to foundations. But, close proximity could inhibit growth and obstruct air circulation, which allows branches and foliage to dry out after the rain. Long-standing moisture invites rust and fungal diseases. 

It’s best to center the root ball at least half the tree’s mature diameter from the exterior walls. Planting them in the right location is key to their success and longevity. 


As previously mentioned, Leyland Cypress trees are fairly drought-tolerant and prefer the soil around them to dry out (roughly down 3”) before being watered again.

The exception to this is when they’re newly planted. To encourage healthy root establishment and minimize planting shock, these should be watered weekly, for the first year.

The same applies to new Thuja saplings. Yet, should continue throughout its lifetime (to include rainfall), as these prefer moist soil. 

Fertilizing Evergreens 

Once mature, Leylands and Thujas will typically acquire nutrients from their surroundings. At this point, extra isn’t needed. But, there are some caveats.

If trees begin to yellow, this may be due to a nutrient deficiency. A fertilizer formulated for evergreens can remedy this. 

The same NPK (in granule form) can be added to the planting hole before adding a new sapling. This will support faster establishment and growth. 

Pests And Diseases 

Being hybrids, these trees are generally pest-free. But, Leylands and Thujas Green Giants can both develop canker disease.

Coryneum canker is a slow-spreading fungus that can damage and disfigure conifers.

Canker results from trees being planted too close together or to your home (inhibiting air circulation) or in poorly draining soil (fungi grow faster in wet environments).

Carefully choosing your planting location and marking out sufficient spacing can help deter the growth of canker. 


After a few years, Thuja and Leyland evergreens can grow quite dense. Another step in ensuring sufficient air circulation and sunlight penetration is proper pruning.

A yearly thinning of branches (in late summer/early fall) will improve these and encourage healthy, new growth at the same time. 

To maintain that beautiful, conical shape while pruning, simply take a bit more off the top and taper off as you move toward the bottom. 

FAQ Leyland Cypress vs Thuja Green Giant 

Leyland Cypress vs Green Giant Final Thoughts 

Weighing the benefits of a Leyland Cypress vs Green Giant Arborvitae is a simple matter of which one best fits your intended use for it, your planting area, and your hardiness zone.

The Green Giant can mature to 100ft by 20ft and thrive in hardiness zones 6-8, where they’re hardy down to -10°F (-23°C).

The Leyland cypress grows to 70ft by 15ft and is far better adapted to warmer regions in zones 6-10. 

Whether you’re interested in a new privacy barrier around your property or adding some formality to your landscape, nothing is more grand and cost-effective than either of these two stunning evergreens.