Green Giant Arborvitae (Thuja ‘Green Giant’) actually has nothing to do with the jolly green giant, which is kind of a bummer. I used to love those commercials as a kid, although I wondered how “ho ho ho” could sound so different coming from him versus Santa. I was a weird kid.
Green Giant Arborvitae are another narrow(ish), tall screening evergreen. They’re often the first alternative to Leyland cypress that landscape contractors recommend, and for good reason. They don’t get as over the top massive as Leylands do. They don’t get decimated by bagworms the way that Leylands do. And, most importantly, they don’t get big and then easily blow over like Leylands do. In case it’s not apparent, I think Leyland Cypress are garbage trees.
Green Giant Arborvitae are fast growing, often putting on a good 2 to 3 feet a year once established. Mature size is around 50 to 70 feet tall by 12 to 15 feet wide, making them significantly larger than Emerald Arborvitae. Unlike Emeralds, however, deer tend to leave Green Giant Arborvitae alone. For that reason we will use them in locations where there’s a real danger of deer damage, like wineries, estate properties, and honestly a good chunk of the homes in Virginia.
The shape of Green Giant Arborvitae is also a bit different from Emerald Arborvitae. Green Giant has a pyramidal, or Christmas tree, shape. Emeralds are more columnar. This means that early on it will seem that you’re getting a lot more screening from an Emerald, but that changes pretty quickly. If you want a dense screen, you can plant Green Giant Arborvitae 6 to 8 feet on center and whatever you want to hide will vanish pretty darn quickly.