If you’re looking for a fast-growing privacy screen that truly lives up to its name, you’ve found it. The question of how tall do green giants grow has a simple answer: very, very tall. The ‘Green Giant’ arborvitae is a superstar in the landscaping world, known for its rapid growth and impressive final height. It can quickly turn a bare yard into a lush, private retreat.
This evergreen is a reliable workhorse for many homeowners. It provides year-round color and structure, and it’s surprisingly adaptable to different climates and soil types. Let’s look at what makes this tree so special and how you can help it reach its full potential in your own garden.
How Tall Do Green Giants Grow
On average, a healthy ‘Green Giant’ arborvitae will reach a mature height of 50 to 60 feet. In perfect conditions, some specimens can even soar to 70 feet or more. That’s as tall as a six-story building! Its width is also substantial, typically spreading 12 to 20 feet wide at the base.
This growth isn’t slow, either. You can expect a growth rate of 3 to 5 feet per year when the tree is young and established. This speedy development is a major reason for its popularity. You get a significant visual impact in just a few growing seasons, which is much faster than many other privacy tree options.
Factors That Influence Their Maximum Height
While the potential is there, several key factors determine how tall your specific trees will get. Understanding these helps you set realistic expectations and provide the best care.
* Sunlight: Full sun is ideal. At least six hours of direct sunlight daily promotes the densest, fastest growth. In partial shade, growth will be slower and the tree may become more leggy.
* Soil Quality: They prefer moist, well-drained, slightly acidic soil. Poor, compacted, or constantly soggy soil will stunt growth and can lead to root rot.
* Climate Zones: ‘Green Giants’ thrive in USDA Hardiness Zones 5 through 7. They can tolerate the warmer parts of zone 8 and the colder parts of zone 4 with some protection, but extreme conditions may limit their ultimate size.
* Spacing: Planting trees too close together forces them to compete for water, nutrients, and light. This competition can reduce their overall size and health.
* Water and Nutrients: Consistent watering, especially in the first few years and during droughts, is crucial. An annual feeding with a balanced fertilizer supports strong growth.
Planning Your Space: Spacing and Placement Tips
Getting the spacing right is the most important step after planting. It prevents future headaches and allows each tree to flourish.
For a traditional privacy hedge where the branches will eventually interlock, plant your ‘Green Giants’ 8 to 12 feet apart, measured from the center of one trunk to the next. If you want each tree to maintain more of its individual, pyramidal shape without heavy crowding, increase the spacing to 14 to 16 feet.
Always consider their future size. Plant them at least 12 to 15 feet away from your house, driveway, or permanent structures to avoid issues with the foundation, roof, or siding as they mature. Also check for overhead power lines; these trees can easily grow into them.
The Lifecycle of a Green Giant Arborvitae
Watching your trees grow is a rewarding experience. Here’s what you can expect over the years.
Years 1-3 (Establishment): The focus is on root development. You’ll see moderate height growth (1-3 feet per year) as the tree settles in. Consistent watering is critical during this phase.
Years 4-15 (Rapid Growth): This is the boom time. With established roots, the tree will put on 3 to 5 feet of height annually, quickly forming your living wall. It’s important to start any shaping pruning early in this stage.
Years 15+ (Maturity): Growth slows significantly to about a foot or less per year as the tree approaches its maximum height. Maintenance becomes simpler, primarily involving monitoring health and occasional pruning.
Planting for Success: A Step-by-Step Guide
Doing the job right at the start gives your trees the best launch possible. Follow these steps for a strong start.
1. Dig the Hole: Make it two to three times wider than the root ball, but only as deep as the root ball is tall. Planting too deep is a common mistake that can suffocate the roots.
2. Prepare the Tree: Gently remove the container. If the roots are tightly circling, score the sides with a knife or gently tease them apart to encourage outward growth.
3. Position and Backfill: Place the tree in the hole, ensuring the top of the root flare is level with the ground. Backfill with the native soil you removed, gently tamping it down to remove large air pockets.
4. Water and Mulch: Create a low soil berm around the edge to form a watering basin. Soak the area thoroughly. Apply 2-3 inches of mulch (like wood chips) around the base, keeping it a few inches away from the trunk itself.
Caring for Your Growing Giants
Once established, these trees are relatively low-maintenance. But a little attention goes a long way in keeping them healthy and tall.
Watering and Feeding Schedule
Water deeply once a week during the first growing season. For mature trees, provide a deep soaking during extended dry periods. A layer of mulch helps retain this precious soil moisture.
Feed your trees in early spring with a slow-release, balanced fertilizer formulated for evergreens. Avoid fertilizing in late summer or fall, as this can promote new growth that won’t harden off before winter.
Pruning and Shaping Techniques
Pruning is optional for health but useful for size control. The best time to prune is in late winter or early spring before new growth emerges. You can also do a light trim in early summer.
Always use sharp, clean tools. Never cut back into the old brown wood, as ‘Green Giants’ often will not regenerate new growth from these areas. Instead, trim only the green, leafy parts of the branches, making your cuts just above a side shoot.
Common Problems and Solutions
Even tough trees can face issues. Catching them early is key.
* Bagworms: These pests create cone-shaped bags on the branches. Hand-pick and destroy the bags in winter or use an appropriate insecticide in early summer when the larvae are active.
* Spider Mites: They cause foliage to look dusty or bronzed. A strong spray of water from a hose can dislodge them, or use a miticide if the infestation is severe.
* Root Rot: Caused by poor drainage. Symptoms include yellowing leaves and dieback. Improve soil drainage immediately and avoid overwatering. Prevention through proper site selection is the best cure for this.
Perfect Companion Plants
Underplanting your ‘Green Giants’ can create a beautiful, layered look. Choose shade-tolerant plants that enjoy similar soil conditions.
Good options include hostas, astilbes, coral bells (Heuchera), and ferns. For a ground cover, consider pachysandra or lilyturf (Liriope). Spring-flowering bulbs like daffodils also work well, as they bloom before the trees cast deep shade.
Frequently Asked Questions (FAQ)
Q: How fast do Green Giant arborvitae grow per year?
A: You can expect 3 to 5 feet of growth per year once the tree is established, usually after the first 2-3 years.
Q: What is the lifespan of a Green Giant tree?
A: With proper care, these trees can live for 40 years or more in a landscape setting, providing long-term structure and privacy.
Q: Can I keep my Green Giants shorter than their natural height?
A: Yes, through annual pruning. You can maintain them at a specific height, but it requires committment. It’s easier to choose a smaller tree variety if you need a height under 20 feet.
Q: How far from a fence should I plant them?
A: Plant the trunk at least 6-8 feet from the fence to allow for the tree’s mature width and to ensure you can access both sides for maintenance.
Q: Do deer eat Green Giant arborvitae?
A: They are notably deer-resistant compared to other arborvitaes, but no plant is completely deer-proof. In times of severe hunger, deer may still browse on them.
The ‘Green Giant’ arborvitae is a fantastic choice for anyone needing a rapid, tall screen. By providing the right conditions—full sun, good soil, adequate space, and consistent water—you give these trees the foundation they need to reach those impressive heights. With minimal care, they will reward you with a beautiful, evergreen backdrop for your garden for decades to come. Remember to plan for their future size from day one, and you’ll enjoy a thriving, problem-free landscape feature.