How Tall Is A 10 Gallon Green Giant Arborvitae?
A 10-gallon Thuja plicata ‘Green Giant’ arborvitae stands about 3 to 4 feet tall when you plant it.
Quick Fact
At planting, expect a 10-gallon Green Giant to top out around 3–4 feet. Over decades, it’ll stretch up to 50–60 feet tall.
Where does the Green Giant arborvitae naturally grow?
This hybrid evergreen thrives across most of the eastern two-thirds of the United States.
The Green Giant arborvitae isn’t a native—it’s a 1930s hybrid born when the Western red cedar (Thuja plicata) met the Japanese arborvitae (Thuja standishii). Those ancestors came from the misty Pacific Northwest and Japan’s cloud forests, but the cultivar itself has settled happily from Minnesota down to Mississippi. Gardeners love it because it shoots up 3–5 feet every year with barely any fuss. (In 2026, it’s still one of the top privacy trees flying off garden-center shelves.)
What are the key measurements for different container sizes?
For a 10-gallon pot, expect the tree to be 36–48 inches tall at purchase, with a mature height of 50–60 feet.
| Container Size | Planting Height (at purchase) | Annual Growth | Mature Height (after 20–30 years) | Mature Width |
|---|---|---|---|---|
| 1 gallon | 12–18 inches | 3–5 feet | 50–60 feet | 15–20 feet |
| 2.5 quart | 6–12 inches | 3–5 feet | 50–60 feet | 15–20 feet |
| 5 gallon | 18–36 inches | 3–5 feet | 50–60 feet | 15–20 feet |
| 7 gallon | 36–48 inches | 3–5 feet | 50–60 feet | 15–20 feet |
| 10 gallon | 36–48 inches | 3–5 feet | 50–60 feet | 15–20 feet |
| 15 gallon | 60–72 inches | 3–5 feet | 50–60 feet | 15–20 feet |
Why is the Green Giant arborvitae so popular?
Gardeners love it for its rapid growth, deer resistance, and low-maintenance needs.
This tree has quite the backstory. Back in the 1930s, a chance seedling popped up at a Danish arboretum. Later, in the 1960s, the U.S. National Arboretum propagated it. Because it’s a hybrid, it almost never produces viable seed, so every tree you buy is a genetic twin of the original. That explains the name—it really does grow like a giant. Even in a 10-gallon pot, you can see 12–18 inches of fresh growth in one season. Deer usually steer clear, bagworms rarely bother it, and tip blight doesn’t stand a chance. The only real catch? Space. Plant it too close to a fence or property line and you’ll be shearing it twice a year just to keep it in check.
What’s the best way to plant and space a 10-gallon Green Giant?
Stick to USDA hardiness zones 5–9, space trees 6–8 feet apart, and give them 8–12 feet from property lines.
- Location: Make sure it’s in USDA hardiness zones 5–9. It’s not picky about soil—clay, loam, or sand all work as long as water drains away. Check your exact zone on the USDA Plant Hardiness Zone Map.
- Spacing: Plant individual trees 6–8 feet apart. For a solid screen, drop that to 5–6 feet. Keep it 8–12 feet from fences or property lines so you’re not constantly trimming it back.
- Soil prep: Mix 2–3 inches of compost into the planting hole. After it’s in the ground, spread 1–2 inches of mulch on top to keep roots cool and moist.
- Pests & diseases: Watch for bagworms, spider mites, and scale. If you spot silken bags dangling from branches in late winter, pick them off by hand. The Arbor Day Foundation suggests a dormant-season horticultural oil spray as a preventive.
- Maintenance: Prune only after the new growth has hardened in late summer. Never remove more than one-quarter of the tree’s natural size, or you’ll weaken it over time.
I can vouch for this one. In my Zone 7A yard, I tucked two 10-gallon Green Giants along the side driveway in spring 2022. By fall that first year they’d already added a foot. By 2026 they form a thick green barrier that blocks both road noise and prying eyes.
