How Big Do Giant Green Arborvitae Get

Giant green arborvitae can get impressively large, reaching heights of 50 to 70 feet and spreading 10 to 15 feet wide.
 
If you’re planting one, you’re probably wondering exactly how big giant green arborvitae get so you can plan your space accordingly.
 
These evergreens are known for their fast growth and dense foliage, making them a popular choice for privacy screens and windbreaks.
 
But their size isn’t just a number; it’s influenced by soil, sunlight, water, and even how you prune them.
 
In this post, we’ll explore the full answer to “how big do giant green arborvitae get?” and what that means for your landscape.
 
Let’s dig in.
 

How Big Do Giant Green Arborvitae Get? A Closer Look at Their Size

When you ask “how big do giant green arborvitae get?” the short answer is that they reach 50–70 feet tall with a spread of 10–15 feet.
 
But let’s break that down into specifics so you know what to expect over the years.
 

1. Typical Mature Height and Spread

Under ideal conditions, giant green arborvitae can get up to 70 feet tall, though most stay around 50–60 feet in residential landscapes.
 
Their spread, or width, usually lands between 10 and 15 feet at full maturity, so they’re not overly wide but do need room.
 
That means if you’re planting a row, space them about 8 to 10 feet apart to avoid crowding.
 
The final size of a giant green arborvitae depends heavily on genetics and local climate.
 

2. Growth Rate and How Fast They Reach Full Size

Giant green arborvitae grow quickly, adding 2 to 3 feet per year in height once established.
 
So if you’re wondering how big giant green arborvitae get after 10 years, expect them to be about 20–30 feet tall.
 
They can reach their full height in 25 to 30 years, which is faster than many other evergreens.
 
This rapid growth is a big reason they’re so popular for screening.
 

3. Comparison to Other Arborvitae Varieties

To understand how big giant green arborvitae get, it helps to compare them to other types.
 
Emerald Green arborvitae only reach 10–15 feet tall, while Giant Green is obviously much larger.
 
Techny arborvitae get about 15–20 feet, and Green Giant (a similar variety) also reaches 50–60 feet.
 
So “giant” is an accurate name for this species.
 

Factors That Influence How Big Giant Green Arborvitae Get

The size of a giant green arborvitae isn’t set in stone; several factors determine whether they hit their maximum potential.
 
Here are the most important ones to know.
 

1. Soil Quality and Drainage

Giant green arborvitae get biggest when planted in well-drained, loamy soil with a pH between 6.0 and 7.5.
 
Poor drainage can stunt their growth and even cause root rot, limiting their final height.
 
If your soil is heavy clay, amend it with compost or plant on a slight mound.
 

2. Sunlight Exposure

Full sun (at least 6 hours per day) is essential for giant green arborvitae to reach their full size.
 
In shady spots, they’ll still grow but will be leggy and much shorter, maybe 30–40 feet instead of 60+.
 
So when planning, choose a location with direct sunlight for best results.
 

3. Water and Irrigation

Consistent moisture, especially during the first few years, helps giant green arborvitae get as big as possible.
 
They don’t like drought, so water deeply once a week if rain is scarce.
 
Too much water, though, can suffocate roots; find a balance.
 

4. Spacing and Competition

If you plant giant green arborvitae too close together, they’ll compete for nutrients and light, reducing each tree’s final size.
 
For a hedge, space them 5–6 feet apart; for individual specimens, give them 10 feet of clearance.
 
Crowded trees won’t get nearly as tall or wide.
 

5. Pruning and Maintenance

Pruning doesn’t usually limit how big giant green arborvitae get unless you top them.
 
Let them grow naturally for maximum height.
 
If you trim the sides, you can control width but not height much.
 

Planting for Maximum Size: How Big Giant Green Arborvitae Get in Landscapes

Knowing how big giant green arborvitae get helps you plan the perfect spot in your yard.
 
Here’s how to set them up for success.
 

1. Choose the Right Location Early

Because these trees get so large, plant them at least 10 feet away from your house, fences, or power lines.
 
They can grow into a formidable size, so give them space upfront.
 
If you’re using them as a screen, consider the mature height so you don’t block a view later.
 

2. Provide Regular Care for the First Five Years

Young giant green arborvitae need consistent watering and a layer of mulch to retain moisture.
 
Fertilize in early spring with a balanced 10-10-10 formula to support rapid growth.
 
This early care directly influences how big giant green arborvitae get as they mature.
 

3. Monitor for Pests and Diseases

Bagworms and spider mites can slow growth, but healthy trees usually outgrow minor infestations.
 
A strong tree will reach its full potential size.
 

So, How Big Do Giant Green Arborvitae Get?

Giant green arborvitae can get impressively large, reaching heights of 50 to 70 feet and spreading 10 to 15 feet wide.
 
Their ultimate size depends on growing conditions like sunlight, soil, water, and spacing.
 
With proper care, you can expect them to grow quickly and fill their space beautifully.
 
Now you know exactly how big giant green arborvitae get, so you can plan your landscape with confidence.
 
Happy planting.