Size
If you're dreaming of a towering evergreen that adds drama to your landscape, how tall can arborvitae grow might surprise you—some varieties reach 50 feet in just 20 years, turning your backyard into a lush green skyline. Whether you're planning a privacy screen or a statement piece, the right arborvitae can grow taller than a two-story house, but not all varieties play by the same rules.
From the compact Emerald Green to the sky-scraping Green Giant, arborvitae come in all shapes and sizes, each with its own growth trajectory. The key to choosing the right one lies in understanding their mature heights and how quickly they grow—because what looks perfect in a catalog might outgrow your space in a decade. Let’s break down the fastest-growing varieties and what you need to know before planting.
Growth isn’t just about genetics—soil quality, sunlight, and even your pruning habits can push an arborvitae to new heights (or stunt it). I’ll share the fastest-growing varieties and how to give yours the best shot at reaching its full potential, whether you’re working with a small urban yard or a sprawling rural plot. Ready to find the perfect fit for your space?
Don’t worry if you’re not a green thumb—even beginner gardeners can coax these evergreens to their full height with a few simple tricks. By the end, you’ll know exactly which arborvitae will thrive in your Zone 6a climate and how to space them for maximum impact. Let’s get growing!
Arborvitae growth heights by variety: which reach 50 feet in 20 years?
Arborvitae (genus Thuja) are nature’s vertical giants, but their final height depends entirely on the variety you choose. Some, like the Green Giant, can tower over your home at 50-60 feet in just two decades, while others like Emerald Green stay compact at 10-15 feet. The difference comes down to genetics, growth rates, and how you care for them. Let’s dive into the tallest performers and what to expect from each.
Most arborvitae grow as evergreen trees, meaning they hold their needles year-round, but their growth habits vary wildly. Fast-growing varieties like Leading Lady or American Arborvitae can add 3-5 feet per year in ideal conditions, while slower growers like Sargentii take their time to reach 30-40 feet. Your climate zone (especially Zone 6a) also plays a role—northern varieties often grow slower than their southern counterparts.
Before planting, check your space: a 60-foot arborvitae needs 20+ feet of clearance from structures, power lines, and neighboring plants. Even "dwarf" varieties like Teddy Bear (3-5 feet) can spread 4-6 feet wide, so spacing matters. I’ll help you match the right tree to your yard’s dimensions.
| Variety | Mature Height | Annual Growth | Best For |
|---|---|---|---|
| Green Giant | 50-60 ft | 3-5 ft/year | Privacy screens, windbreaks |
| Emerald Green | 10-15 ft | 6-12 in/year | Foundation planting, small yards |
| Leading Lady | 12-15 ft | 2-3 ft/year | Narrow spaces, urban gardens |
| American Arborvitae | 30-40 ft | 1-2 ft/year | Wildlife habitat, large landscapes |
| Slender Giant | 30-40 ft | 2-3 ft/year | Tight spaces, columnar look |
The Green Giant is the undisputed champion for height, but it’s not the only fast grower. Leading Lady offers a balance of speed and compact size, making it ideal for urban gardens where space is limited. If you’re after a natural, untamed look, the American Arborvitae grows slower but develops a stunning, irregular shape over time. For a neat, columnar silhouette, Slender Giant is a game-changer—it grows tall but stays narrow, perfect for tight spaces.
One common misconception is that all arborvitae grow as trees. Some, like Emerald Green, are bred as shrubs and stay low to the ground, making them perfect for hedges or foundation plantings. Even these "dwarf" varieties can spread 3-5 feet wide, so don’t underestimate their horizontal growth. Always check the mature width label when shopping, as it’s just as critical as height.
Your Zone 6a climate will influence growth rates, too. In cooler northern regions, arborvitae grow slower but develop hardier wood that resists breakage in winter storms. Southern varieties, like Green Giant, thrive in heat but may struggle in prolonged freezes. If you’re on the fence, opt for hybrid varieties like Thuja standishii, which adapt well to Zone 6a and beyond.
Pro tip: If you’re planting near a property line, check local regulations—some areas require setbacks for trees over 15 feet tall. A Green Giant planted too close to a fence could become a liability (and a headache) as it matures. Always measure twice before digging!
Ready to pick the perfect arborvitae for your space? Next, I’ll show you how to maximize growth without sacrificing health, including the best soil prep, pruning schedules, and watering tricks to turn your evergreen into a backyard skyscraper. 🌲
How to maximize arborvitae height without sacrificing health
Want your arborvitae to hit its full height potential without risking poor health? The secret lies in soil prep, pruning timing, and consistent watering. Many gardeners unknowingly stunt growth by over-pruning or neglecting drainage—let’s fix that. Start with well-draining soil rich in organic matter, like compost or aged manure. Arborvitae thrive in slightly acidic soil (pH 6.0-7.0), so test your soil before planting. If it’s too alkaline, amend with peat moss or sulfur to encourage faster, healthier growth.
Avoid the common mistake of over-fertilizing with nitrogen-heavy mixes. While a balanced 10-10-10 fertilizer in early spring gives a growth boost, too much can lead to soft, floppy branches that snap in storms. Instead, focus on slow-release organic fertilizers like fish emulsion or bone meal. Apply it in early spring and again in mid-summer for steady, sturdy growth. Skip fall applications—new growth in cool weather is vulnerable to frost damage.
Pruning is where most gardeners go wrong. Never trim more than 20% of the foliage in one year, or you’ll shock the tree into stunted growth. The best time to prune is late winter or early spring, just before new growth begins. Use clean, sharp shears to make cuts at a 45-degree angle just above a bud. For tall varieties like Green Giant, focus on removing dead or crossing branches to maintain an open canopy—this lets sunlight penetrate deeper, fueling vertical growth.
Watering is another critical factor. Young arborvitae need deep, consistent moisture—about 1-2 inches per week during the growing season. Use a soaker hose or drip irrigation to keep roots moist without wetting the foliage (which invites fungal diseases). Once established (after 2-3 years), arborvitae become drought-tolerant, but they still need weekly deep watering during dry spells. Mulch with 3-4 inches of wood chips to retain moisture and protect roots from temperature swings.
Sunlight is non-negotiable for height. Arborvitae need 6+ hours of full sun daily to reach their maximum potential. In Zone 6a, plant them in south-facing spots where they’ll get morning sun and afternoon shade if needed. If your yard is shady, choose tolerant varieties like Emerald Green, but expect slower growth. Avoid planting near large trees that compete for water and nutrients—arborvitae hate root competition.
Finally, monitor for pests and diseases that can derail growth. Arborvitae canker and root rot are silent killers—look for oozing sap, wilting branches, or mushrooms at the base. If you spot these, prune infected areas immediately and improve drainage. For fastest growth, combine these tips with regular mulching and minimal disturbance to the root zone. With the right care, your arborvitae will grow taller and healthier than ever—turning your yard into a lush, green vertical masterpiece. 🌿