This post contains affiliate links. As an Amazon Associate I earn from qualifying purchases. If you click a link and make a purchase, I may receive a small commission at no extra cost to you.
Giant arborvitae can get quite wide, with a mature spread typically reaching 8 to 12 feet.
How wide do giant arborvitae get depends heavily on the specific cultivar you choose.
Some giant arborvitae varieties can stretch even wider, sometimes up to 15 feet across.
In this post, we’ll answer exactly how wide giant arborvitae get, what influences their spread, and how to plan your landscape around their size.
Let’s dive in and explore the width of these majestic evergreens.
How Wide Do Giant Arborvitae Get? The Typical Spread
The short answer to how wide do giant arborvitae get is that they have a moderate to large spread.
Most giant arborvitae (Thuja plicata) grown in home landscapes will eventually fan out to a width between 8 and 12 feet.
But the exact width depends on the genetics of the tree and the growing conditions.
1. Cultivar Makes a Big Difference in Width
Not all giant arborvitae are created equal when it comes to spread.
The straight species *Thuja plicata* can become quite wide, sometimes exceeding 15 feet at the base.
But many popular cultivars are bred to retain a narrower form.
For instance, ‘Green Giant’ arborvitae is often listed as reaching 10 to 12 feet wide at maturity.
In contrast, ‘Zebrina’ may hold a slightly tighter silhouette, closer to 8 feet across.
So when you’re asking how wide do giant arborvitae get, always check the tag for the specific variety.
2. Age Plays a Role in Giant Arborvitae Spread
Young giant arborvitae are quite skinny and upright for the first several years.
As the tree matures, its lower branches start to arch outward, and the width increases steadily.
A 10‑year‑old giant arborvitae might only be 4 to 5 feet wide, while the same tree at 20 years could be 10 feet wide.
Full width is often reached between 20 and 30 years for most varieties.
So the answer to how wide do giant arborvitae get also depends on how long they’ve been growing.
3. Spacing Affects the Actual Width
If you plant giant arborvitae close together as a hedge, they won’t reach their full individual spread.
When crowded, the lower branches may die back from lack of light, and the trees will stay narrower.
Conversely, a specimen tree with plenty of room to breathe can grow to its natural width.
This is a key point when planning how wide do giant arborvitae get in your own yard.
Factors That Influence How Wide Giant Arborvitae Get
Several environmental and care factors directly affect how wide giant arborvitae get.
Understanding these helps you predict and even control their spread.
1. Sunlight Exposure
Giant arborvitae thrive in full sun to partial shade.
In full sun, they tend to grow denser and wider because all sides receive even light.
In shade, the tree may stretch upward but remain narrower, with sparse interior branches.
So if you want a wider tree, give it plenty of sunshine.
2. Soil Quality and Moisture
Rich, well‑drained soil with consistent moisture encourages vigorous growth, including lateral spread.
Poor soil that is too sandy or too clay‑heavy can stunt root development and limit how wide giant arborvitae get.
A tree stressed by drought will often prioritize growing upward rather than outward.
Amend your soil and water deeply during dry spells to support maximum width.
3. Pruning and Maintenance
If you prune the tips of the branches, you can encourage a denser, fuller profile.
However, heavy pruning can also reduce the overall spread, especially if you cut back the leading shoots.
For natural‑looking width, let the tree grow unpruned and only remove dead or damaged branches.
This directly impacts how wide do giant arborvitae get in your landscape.
Planting Considerations for Giant Arborvitae Width
Before you buy, it helps to know how wide do giant arborvitae get so you space them correctly.
Here are practical tips for incorporating their spread into your design.
1. Space Hedges Properly
For a continuous screen, plant giant arborvitae 5 to 6 feet apart.
At that spacing, the trees will eventually touch and form a solid wall without competing too heavily.
If you want each tree to reach its full width, give them at least 10 feet of space.
Spacing is one of the most common mistakes when people ask how wide do giant arborvitae get.
2. Keep New Plantings Well Watered
Young trees need consistent moisture for their first two years to establish a strong root system.
A healthy root system supports wider growth as the tree matures.
Mulching around the base helps retain moisture and keeps roots cool.
This simple step can help your giant arborvitae reach its potential width.
3. Avoid Planting Too Close to Structures
Remember that the mature width can be 12 feet or more.
Plant at least 6 feet away from your house, fence, or driveway to prevent damage and overcrowding.
Knowing how wide do giant arborvitae get helps you avoid future problems with overhanging branches.
So, How Wide Do Giant Arborvitae Get?
How wide do giant arborvitae get depends on the variety, age, and growing conditions.
On average, giant arborvitae get 8 to 12 feet wide at maturity, with some cultivars reaching 15 feet.
Young trees start narrow but widen over decades as branches arch outward.
Spacing, sunlight, soil, and pruning all influence the final spread.
Now that you know how wide giant arborvitae get, you can plan your landscape with confidence.
Enjoy watching your evergreens grow into their full, beautiful width.