"These things will screen the whole yard in two years," my neighbor said over the fence the spring he planted his row of Green Giants. They did. Then they kept going. Three seasons later the trees crowded his driveway and threw shade across the vegetable garden he was so proud of. I had put Emerald Green along my own north line instead, and it still sat right where I planted it.
The Green Giant arborvitae disadvantages come down to one thing above all: size. This is a big tree pretending to be a hedge. The fast growth and tall reach that sell you a quick screen are the same traits that make it crowd your small lot and shade everything around it within a few years.
Look at the Green Giant arborvitae size and your trade-off gets clear. It puts on a fast 3 to 5 feet of growth per year and matures at 40 to 60 feet tall. That speed fills your privacy gap fast. But the tree does not stop at fence height. It keeps climbing until it towers over your house, drops needles in your gutters, and steals the morning sun from your beds.
Width is the part you can miss on the nursery tag. A mature Green Giant spreads 12 to 20 feet wide. Set one four feet off your property line and it will hang over the neighbor's driveway in a handful of seasons. You also cannot fix that by cutting the top off. Arborvitae follows a no-regrowth rule, so once you top it past the green needles into bare wood, that cut stays bare. Your topped tree turns into an ugly stub for good.
There is a cold-hardiness catch too. Green Giant performs best in USDA zones 5 to 8. Push it colder than that and winter burn and dieback set in. Emerald Green takes the cold far better, which matters if you garden up north where harsh winters would stress your bigger tree.
Outgrows small yards
- Mature height: Reaches 40 to 60 feet, far taller than a backyard hedge needs, so it towers over the house and shades the garden.
- Fast growth: Adds 3 to 5 feet a year, which means it overshoots fence height in just a few seasons.
- Shading neighbors: That height blocks sun from your own beds and your neighbor's yard, a common source of fence-line disputes.
Demands wide spacing
- Mature width: Spreads 12 to 20 feet, so a row needs 5 to 6 feet between trees and real room off the property line.
- Crowding risk: Planted too close to a drive or fence, it swallows the path and pushes against structures.
- Wasted ground: A small lot rarely has the open space this tree wants to fill.
Limited cold hardiness
- Best zones: Thrives in USDA zones 5 to 8 and struggles colder than that.
- Winter damage: Hard northern winters cause browning and dieback on exposed plants.
- Better cold pick: Emerald Green handles deep cold far more reliably.
Cannot be safely topped
- No regrowth: Cutting into bare wood leaves a permanent dead gap, since the tree will not push new growth there.
- No height control: You cannot keep it short by topping it like you would a shrub.
- Stuck with the size: Once it is too tall, removal is often the only real fix.
So how does Green Giant vs Emerald Green shake out for your tight yard? Emerald Green stays slim at 3 to 4 feet wide and tops out near 12 to 15 feet. It holds its lane against your fence and never blocks the light. Green Giant is built for open acreage, not a city lot.
For your small yard, plant Emerald Green or a dwarf arborvitae instead. You get a tidy, full screen that fits your space and stays put. Save Green Giant for a large property where you have 20 feet of width to spare and no neighbors close enough to lose their sun. Pick your tree for its size in ten years, not the photo on the tag.
Read the full article: Arborvitae Shrub: Complete Growing Guide
