If you’re looking for a fast-growing evergreen to create a privacy screen, you’ve probably asked how tall do green giant arborvitae grow. These popular trees are known for reaching impressive heights quickly, making them a top choice for many homeowners. In just a few years, they can completely change the look and feel of your yard.
This guide will give you all the details on their growth, from their potential size to the care they need to thrive. You’ll learn what to expect when you plant them and how to manage their height over time.
How Tall Do Green Giant Arborvitae Grow
The Green Giant arborvitae is a true giant. Under ideal conditions, it can reach a mature height of 50 to 60 feet. Its spread, or width, is typically 12 to 20 feet at the base. This creates a tall, dense, pyramidal shape that’s perfect for blocking wind or unwanted views.
What’s most remarkable is their speed. They are one of the fastest-growing conifers you can plant. Here’s a typical growth timeline:
- Years 1-3: After establishment, they can grow 1 to 2 feet per year.
- Years 4-10: This is their peak growth period. It’s common for them to add 3 feet or more in height each year.
- Maturity: They will begin to slow down as they approach their maximum height, which can take 20 to 30 years.
Factors That Influence Their Final Height
Not every Green Giant will hit 60 feet. Several key factors determine how tall yours will get.
Sunlight and Soil Conditions
These trees demand full sun to partial shade. At least 6 hours of direct sunlight is crucial for optimal growth. In heavy shade, they will grow thin and leggy, and their height will be stunted.
They prefer moist, well-drained, fertile soil. While they are adaptable to various soil types, poor, compacted, or constantly soggy soil will seriously limit their growth potential and can lead to health problems.
Climate and Hardiness Zone
Green Giants are hardy in USDA zones 5 through 7, and they often succeed in protected parts of zone 8. They grow best in regions with decent summer rainfall and moderate temperatures. Extreme heat and drought without supplemental watering will slow them down.
Spacing and Competition
How you space them matters. For a dense privacy hedge, people often plant them 5 to 8 feet apart. At this spacing, they will eventually compete for resources, which may limit the ultimate height of each tree. Planted as a solitary specimen with ample space on all sides, a Green Giant is much more likely to reach its full, majestic height.
Planting for Success and Rapid Growth
Getting your tree off to a strong start is the best way to ensure it grows tall and healthy quickly. Follow these steps.
- Choose the Right Spot: Pick a location with full sun and enough space for its mature width. Remember to check for overhead power lines or structures.
- Dig a Proper Hole: The hole should be two to three times wider than the root ball, but no deeper. Planting too deep is a common mistake that can suffocate roots.
- Prepare the Root Ball: Gently loosen any circling roots. If the tree is pot-bound, you may need to make a few shallow cuts down the sides of the root mass.
- Plant and Backfill: Place the tree in the hole. Backfill with the native soil, unless it is very poor. You can mix in some compost, but avoid over-amending.
- Water Deeply: Create a soil berm around the edge of the hole to form a watering basin. Soak the area thoroughly to settle the soil and eliminate air pockets.
- Mulch: Apply 2-3 inches of organic mulch, like shredded bark, around the tree. Keep the mulch a few inches away from the trunk itself to prevent rot.
Ongoing Care to Maintain Health and Height
Once established, Green Giants are relatively low-maintenance. But a little care goes a long way in promoting vigorous growth.
Watering Schedule
Consistent moisture is key, especially for the first two years and during dry spells. Deep, infrequent watering is better than frequent shallow sprinklings. Aim to provide about 1 inch of water per week, either from rainfall or your hose. A soaker hose works wonderfully for this.
Fertilizing for Growth
Fertilize in early spring before new growth begins. Use a balanced, slow-release fertilizer formulated for evergreens or acid-loving plants. Follow the label instructions carefully. Over-fertilizing can cause excessive, weak growth that’s susceptible to damage.
Pruning and Shaping
One of the great things about Green Giants is that they require minimal pruning. If you are growing them as a hedge, you can trim them once or twice a year to control width and encourage density.
- The best time to prune is in late winter or early spring before new growth starts.
- You can also do a light trim in mid-summer if needed.
- Avoid cutting back into old, brown wood, as it may not regenerate new green growth.
- Never remove more than one-third of the tree’s greenery in a single year.
Common Problems That Can Stunt Growth
Even tough trees can have issues. Watch for these signs that might be limiting your tree’s potential.
Bagworms: These pests can defoliate a tree quickly. Look for small, cone-shaped bags hanging from the branches. Hand-pick them in winter or use an appropriate insecticide in early summer when the larvae are small.
Spider Mites: In hot, dry weather, spider mites can cause the foliage to look bronzed or dusty. A strong spray of water from a hose can dislodge them, or you can use horticultural oil.
Root Rot: This is often caused by poorly drained soil. Symptoms include discolored, wilting foliage and stunted growth. Prevention through proper site selection is the best cure.
Winter Burn: In exposed, windy sites, foliage can dry out and turn brown in winter. This rarely kills the tree but can mar its appearance and slow its growth for the season. Anti-desiccant sprays can offer some protection.
Planning for Their Impressive Size
It’s easy to underestimate how big these trees get. Always plan for their mature dimensions, not their size at the garden center. Planting them too close to your house, driveway, or property line can lead to big problems in 10 years.
As a hedge, their fast growth means you’ll have privacy sooner. But you’ll also need to commit to annual trimming to keep their width in check. If you prefer a more natural look, give them plenty of room to grow into their stately, pyramidal form.
FAQ: Your Green Giant Questions Answered
How fast do Green Giant arborvitae grow per year?
Once established, they can grow 3 feet or more per year during their peak growth period. In the first few years, expect 1-2 feet of annual growth.
Can I keep my Green Giants at a certain height?
Yes, you can control their height through pruning. Topping the tree—cutting off the central leader—will encourage it to grow wider. You’ll need to continue pruning the top each year to maintain a lower height.
What is the best time of year to plant them?
Early fall is ideal, giving the roots time to establish before winter. Spring is also a very good time, as long as you can provide consistent watering through the first summer.
How far from my fence should I plant Green Giant arborvitae?
Consider their mature spread of 12-20 feet. Plant the trunk at least 6-10 feet from the fence line to allow the lower branches room to grow and for you to access the fence for maintenance.
Do deer eat Green Giant arborvitae?
They are marketed as deer-resistant, but no plant is truly deer-proof. In areas with high deer pressure or during harsh winters, deer may browse on them, especially younger trees. Protection is recommended for the first few years.
Green Giant arborvitae are a fantastic solution for anyone needing a fast, tall screen. By understanding their growth habits and providing simple care, you can enjoy these impressive evergreens in your landscape for decades to come. Just be sure to give them the space they need to reach there full potential.