How to Plant, Grow, and Care For Thuja ‘Green Giant’ Arborvitae

Are you shopping for arborvitae but aren't sure which variety to choose? The ‘Green Giant’ has a lot to offer gardeners. In this article, gardening expert Jill Drago details everything you need to know about planting, growing, and caring for ‘Green Giant’ arborvitae.

Written by Jill Drago Horticulture review by Sarah Jay Last updated: April 12, 2024 | 7 min read

A close-up reveals the lush foliage of 'Green Giant' arborvitae, showcasing its vibrant green color and dense, conical shape. This popular landscaping choice stands tall with its towering height, offering privacy and beauty to outdoor spaces.

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Arborvitae are evergreen shrubs that are popular for hedging. You can find a handful of arborvitae varieties at your local garden center, but if you are looking for a very large and dependable variety, ‘Green Giant’ is a great choice.

These shrubs are easy to grow, but if you are looking for a few tips on how to get your shrubs started off on the right foot you’ve come to the right place. In this article, I will help you decide if this is the right shrub for your yard and help you learn how to care for it. Let’s dig in!

‘Green Giant’ Arborvitae

‘Green Giant’ Arborvitae:

grow three to five feet per year, reaching 30-50 ft. tall
have thick green foliage
are ideal for screening and hedging
are easy-to-maintain

buy at Epic Gardening Shop

Overview

Within a green park, majestic Thuja trees stand proudly, their foliage dense and verdant under the clear blue sky. These towering giants provide shade and tranquility, their branches reaching towards the heavens in a graceful display of nature's splendor. — The ‘Green Giant’ arborvitae grows 40-60 feet tall.


Plant Type Conifer Family Cupressaceae Genus Thuja Species standishii x plicata	Native Area Europe Exposure Full sun to partial shade Height 40-60 feet Watering Requirements Average	Pests and Diseases Minimal instances of bagworms, scale, and root rot Maintenance Low Soil Type Clay, loam. Fertile and well-draining Hardiness Zone 5-8

What Is It?

The ‘Green Giant’ arborvitae is a lovely evergreen shrub that soars to high heights. Often used for a privacy screen, this arborvitae has many uses within our gardens.

It is low maintenance and quick growing. Lush deep green foliage will grow into a pyramidal shape. This shrub does not lose its shape easily and makes for perfect hedges, privacy screens, or specimen plants.

Native Area

A close-up reveals the vibrant, glossy leaves, showcasing their rich green hue and finely textured surface. The leaves are arranged densely along the branches, creating a lush and full appearance, perfect for providing privacy and screening in gardens. — This plant is non-native but adaptable to various climates.

This popular hedging plant is a hybrid between the Western Red Cedar and Japanese Arborvitae. Therefore, this variety is not technically native to any region. However, it is very adaptable to a variety of climates.

Characteristics

The meticulously trimmed Thuja trees stand in rows, their neat, symmetrical shapes evoking a sense of order and tranquility. These trees line the park walkway, offering a picturesque avenue for strolling or leisurely enjoying nature. Their uniformity adds a touch of elegance to the park landscape. — Growing into an elegant, pyramidal shape, this is a towering, low-maintenance conifer with lush, scale-like leaves.

‘Green Giant’ is an evergreen conifer. Each branch is tightly packed with scale-like leaves, giving this shrub a full and lush appearance.

It will reach towering heights of 60 feet and grow up to 18 feet wide. This shrub naturally grows into an elegant pyramidal shape that is easy to tend to and does not require pruning to maintain.

Planting

‘Green Giant’ arborvitae are typically found at garden centers in plastic nursery pots or balled and burlapped. Either way, the planting method is the same!

Transplanting

A close-up of arborvitae plants in pots, showcasing vibrant green leaves with delicate textures, each leaf bearing tiny scales. The pots rest elegantly on decorative tiles, adding a touch of charm to the botanical display. This scene invites a serene appreciation of nature's intricate beauty. — For a hedge or screen, plant shrubs 5-6 feet apart in one row.

Once you bring your new shrub home from the garden center and pick the correct location, it is time to dig! Before you start- it’s a good idea to water your shrub while it is still in its container. This can help reduce the risk of transplant shock.

Planting Steps

Dig a hole twice as wide and a bit deeper than the container that your arborvitae is growing in.
Carefully remove the plant from its growing container and gently loosen the roots.
With help, position your shrub in your freshly dug hole.
Gently spread the roots out within the hole. This small step will help your roots grow evenly while also allowing them to absorb as much water and nutrients from your soil as possible.
Slowly begin to backfill with garden soil. You will want to backfill until the soil level is the same as it was in the nursery pot. If you need to readjust the arborvitae to achieve the correct soil level, do it. It will be worth your time in the end.
Lightly pack the soil down around the roots when you have finished backfilling.
Next, build a dike around the root zone. This will keep water from running away in this crucial time.
Add a layer of compost to the top of the soil. One inch will do.
Next, add mulch to help keep weeds away and retain water. Keep the mulch a few inches away from the trunk of the tree to keep your arborvitae healthy.
Finally, water!

If you have plans to grow a hedge or privacy screen, plant your shrubs five to six feet apart in a single row. Or, you can stagger the shrubs in two rows. In this case, plant the shrubs 8-15 feet apart in each row, with the second row of plants staggered in between.

How to Grow

Arborvitae has a reputation for being extremely low maintenance. Of course, having a few tricks up your sleeve can help these plants grow to be their best selves. Let’s take a look.

Light

A close-up of trimmed Thuja trees, forming neat rows with their lush foliage perfectly manicured. These Thuja trees create a captivating sight as they line the park's walkway, providing both shade and aesthetic appeal to passersby. The symmetrical arrangement offers a sense of harmony in the urban landscape. — Arborvitae thrives in full sun but tolerates partial shade.

‘Green Giant’ grows best in full sunlight, although it is tolerant of partial shade. If you live in a warmer climate, It benefits from afternoon shade.

Water

A close-up reveals Thuja foliage, its vibrant green leaves delicately tapered at the tips. Rain droplets glisten atop each leaf, reflecting the surrounding light. The leaves seem refreshed, a testament to nature's nurturing touch. — Sustain these shrubs with consistent watering to avoid dryness.

Keeping your plant watered regularly is really important, especially for newly planted shrubs. If these shrubs go too long without water, the foliage will dry out, and you will end up with brown, unattractive shrubs.

While you may be tempted to let up on autumnal watering, don’t! These shrubs need as much moisture going into the winter as possible.

Soil

This arborvitae is not picky about the type of soil it grows in. It is recommended that you grow ‘Green Giant’ in well-draining soil.

Temperature and Humidity

A close-up of a small Thuja tree reveals delicate, scale-like leaves arranged in flattened sprays. Each leaf is a vibrant shade of green, adding texture and depth to the tree's appearance. Surrounding the tree, sparse green grasses peek through the rich, fertile soil. — Plant this shrub cautiously near coastal areas or roads with salt.

‘Green Giant’ thrives in zones 5-8. These large shrubs are tolerant of varying amounts of humidity.

As with other arborvitae, this cultivar is sensitive to salt spray. If you live in a coastal region or an area that uses salt on the roads, take care not to plant too close to the source of the salt.

Fertilizing

A large Thuja tree dominates the foreground, showcasing its lush foliage of needle-like leaves. These leaves are tightly packed, creating a dense and verdant canopy. In the background, other trees with sparse branches and small leaves dot the landscape under a clear blue sky. — Wait a year before fertilizing arborvitae.

Take care when fertilizing your arborvitae. Do not fertilize these shrubs within their first year of growing in your yard. Allow these plants time to acclimate and get established in their new home.

In the second year, you can begin to add a balanced fertilizer to your soil. Use one that is specific to evergreen trees and shrubs. Once you notice that your shrub has been growing happily for a few years in your yard, you can hold off on the fertilizer.

Maintenance

Pruning is not necessary and only needs to be done for aesthetic reasons, such as broken branches or irregular growth that could be taking away from the shape of the plant. If you do need to prune, this should be done in late winter or early spring. — Prune for aesthetics in late winter.

‘Green Giant’ arborvitae are very low-maintenance plants. The only extra care they may require is pruning. Pruning is not necessary and only needs to be done for aesthetic reasons, such as broken branches or irregular growth that could be taking away from the shape of the plant. If you do need to prune, this should be done in late winter or early spring.

Propagation

The easiest and most successful method of propagating arborvitae is by taking softwood cuttings.

Cuttings

A close-up of lush Thuja trees standing tall in a vibrant forest setting. The dense foliage of the Thuja trees creates a verdant canopy, providing shade and shelter for the surrounding environment. Each leaf of the Thuja trees glistens with a glossy green hue, adding to the allure of the natural landscape. — Propagate arborvitae via softwood cuttings.

‘Green Giant’ is best propagated from softwood cuttings towards the end of the summer.

Take as many cuttings as you like of softwood cuttings that have new foliar growth on them.
Remove lower leaves from your cutting. This will create wounds and help expose any growth points from the stem.
Stick your cutting into rooting hormone, then stick it into a container with moist sand.
Place a clear plastic bag over the top of the cuttings. This will create a greenhouse effect and will trap any moisture in the air.
Keep your cuttings in indirect light for about two months.
Slightly tug on your cuttings. When they show resistance, you will know roots are forming.

Keep the cutting in this pot for as long as you like. The stronger the root system, the better the transplant will be. Before planting in your garden, harden your cutting off by leaving it outdoors in a protected space for a week or two as it gets used to the elements.

Other Arborvitae

If ‘Green Giant’ is not for you, here are a few other arborvitae options that may suit your garden a bit more.

Western Arborvitae ‘Whipcord’

	botanical name Thuja plicata ‘Whipcord’
	sun requirements Full sun to partial shade
	height 4-5 feet
	hardiness zones 5-7

‘Whipcord’ has a whimsical growth habit, unlike the near-perfect ‘Green Giant’. This arborvitae is deep green and mop-like in appearance. This is a much smaller arborvitae and would work as a specimen plant, or in large containers.

Oriental Arborvitae

	botanical name Platycladus orientalis
	sun requirements Full sun to partial shade
	height 18-25 feet
	hardiness zones 6-9

Oriental arborvitae is similar to ‘Green Giant’ in that it produces lush and dense foliage, making it excellent for privacy screens or hedges. This arborvitae, however, will max out at about 25 feet tall. The foliage of the oriental arborvitae begins as a yellow-green before settling into a deep green upon maturity.

American Arborvitae ‘Tiny Tim’

	botanical name Thuja occidentalis ‘Tiny Tim’
	sun requirements Full sun to partial shade
	height 6 inches to 1 foot
	hardiness zones 2-7

On the other end of the spectrum is ‘Tiny Tim,’ a very cute and tiny arborvitae. This small shrub is perfect for containers or for a low-growing hedge or border plant. ‘Tiny Tim’ grows globe-shaped and produces lush green foliage.

Common Problems

This arborvitae is relatively problem-free! Unfortunately, if it is not growing in the right conditions, such as soil that does not drain, you can run into a few pests. Let’s take a look!

Pests

‘Green Giant’ arborvitae is resistant to many pests, but as always there is a risk of insects for any plant in your garden. Let’s take a look at two of the more common and specialized insects for this type of arborvitae.

Bagworm

Bagworms are caterpillars that love to hang out on evergreens. These crawlers are easy to spot because they create bags around their bodies that resemble pinecones. These caterpillars can defoliate a sizeable area of your arborvitae.

They can also cause nearby foliage to bronze. Handpick bagworms or use Bt on bagworms in the larval stage. Most of the time, bagworms aren’t an issue at all, though, and don’t require control.

Scale

Arborvitae has a specialized scale insect pest called the Fletcher scale or Arborvitae soft scale. As with other scales, once they hatch from their eggs, they will quickly find a feeding site and remain there for the rest of the season, sucking fluids out of your plant.

Penn State University recommends horticultural oil in the springtime. If you do not notice the scale insects until later in the season it is best to seek professional help in spraying pesticides.

Diseases

A close-up of Thuja tree branches, the leaves present a striking duality. Some sections appear dried and brown, hinting at past stress or dehydration, while others boast lush, verdant greenery, signifying health and vitality. This contrast illustrates the tree's resilience amid changing environmental conditions. — Regularly inspect roots for signs of rot.

Root rot is a common disease that can be found in soil that is not well-draining. If the roots of arborvitae remain wet for too long they will begin to rot. Because this is occurring underground we typically do not notice that this unfortunate disease has taken hold until it is too late.

The best way to deal with root rot is to prevent it. Amend your soil before planting your shrubs, and monitor your watering schedule to make sure your soil is drying out a bit in between watering sessions.

Frequently Asked Questions

This large arborvitae has qualities that make it as near to deer resistant as possible. Many arborvitae are not resistant to wildlife, which is why ‘Green Giant’ is a great variety to choose if you live in wooded areas. It should be noted that when food is scarce, critters will nibble on whatever they can find.

The best way to prevent deer damage in your yard, according to the University of Rhode Island, is to plant a selection of less preferred plants. Lucky for us, arborvitae fits the bill!

To a degree. Arborvitae is considered mildly toxic to pets. This shrub contains a neurotoxin called Thujone that can cause itching and other mild symptoms if it is consumed in large amounts.

The most important thing you can do for your shrub going into the winter is to water it. Give your shrubs a deep watering before the ground freezes. This will keep the foliage hydrated throughout the winter months.

Another option is wrapping your arborvitae. This is not always necessary, and it depends on what your arborvitae is exposed to. If your plants are near a road or are exposed to a lot of wind you should wrap your arborvitae. Wrap your arborvitae from the bottom up with burlap, using twine to secure the burlap in place.

Final Thoughts

‘Green Giant’ arborvitae are beautiful shrubs that are very useful in our gardens. These shrubs quickly provide privacy within our yards while also remaining green and healthy all year long. If you live in an area with a large deer population, arborvitae stand a good chance of remaining untouched.

These plants are more than just hedges or privacy screens, though. Plant one or two as anchors to your foundation garden, or add them to the back of an evergreen border. The options are endless with ‘Green Giant’.

How to Plant, Grow, and Care For Thuja ‘Green Giant’ Arborvitae