Thuja Green Giant Trees

If you’re looking for a fast-growing evergreen tree, look no further than Thuja ‘Green Giant’. This tall evergreen plant is perfect for privacy screening, fast-growing shade (when planted on the south side of a property lot) and winter color when everything else in the landscape is brown and dreary.

Why Everyone Loves Thuja ‘Green Giant’

Thuja ‘Green Giant’ grows almost everywhere. It is hardy in USDA zones 5-9, which covers a huge portion of the United States. From the Northeast to the Southeast to the Midwest, Thuja ‘Green Giant’ is the hedging and screening plant of choice. It isn’t picky about soil and will grow in sandy soils and heavy clay soils equally well. It is also practically maintenance-free. The only major maintenance is hedge shearing after several years of growth. Unlike some evergreen plants, Thuja ‘Green Giant’ has few pest and disease problems. If you’ve had problems with Leyland Cypress in your yard, this plant is a great replacement.

Possibly the best feature of this evergreen is that deer don’t favor the taste. What’s the point in planting a beautiful evergreen if you have to cover it up with burlap or deer netting every winter? Thuja ‘Green Giant’ does just fine without those ugly protections. If you live in an area with heavy deer pressure, spray Thuja ‘Green Giant’ every three to six months with deer repellent. That’s all the protection you need.

How to Plant Thuja ‘Green Giant’

This is a large landscape tree, and as such, requires a bit of planning before planting. First, measure the area where you would like to plant your hedge or row. You will primarily need the length of the area of planting to estimate the number of trees you need. Once you have the length of your planting area, you can determine the number of trees you need.

Thuja ‘Green Giant’ is a fast-growing tree that can grow up to three feet a year. The mature height is 60 feet. It will reach 30 feet in 30 years, with a final spread of 12-20 feet. On its own, it makes a majestic focal point tree for the corner of the yard. Planted in a row, it forms a dense hedge quickly. To achieve this effect, plant Thuja ‘Green Giant’ trees 8 feet apart in a row. If you want to maintain the pyramidal/conical form, plant the trees 14 feet apart in a row. The closer together you plant, the denser the hedge and the more trimming you’ll have to do to maintain shape.

When planting Thuja ‘Green Giant’ dig a hole for each tree that is twice as wide as the rootball but just as deep as the rootball. You don’t need to add anything to the planting hole. Take the tree out of the pot and place it in the hole. The soil around the tree should be at the same level as the soil around the planting hole. If the tree looks like it is too deep—that is that the root ball is below the surrounding soil level, pick up the tree and toss some more soil into the hole. Trees will settle a bit after planting, and you never want the point where the tree roots meet the trunk to be under the soil.

Then, once you have the hole depth adjusted, fill in around the tree with the same soil you took out when digging the hole. Water the tree by holding the hose on it and counting to 20.

How to Care for Thuja ‘Green Giant’

These are “easy growing” trees, so there isn’t much you have to worry about. There are a few tips, however, that will help you help your new trees get started for a lifetime of healthy growth. Follow these tips to keep your Thuja ‘Green Giant’ growing.


  • Help your new trees get started by mulching around them. A layer of shredded hardwood mulch, three inches deep, extending one to two feet out from the tree trunk will help the soil retain moisture for the tree. Resist the urge to “volcano” much! Do not pile the mulch up around the tree trunk. Pull the mulch away from the trunk at least three inches all the way around.


  • Water your new tree every other day by holding a hose around it and counting to 20. If you don’t have a hose, five full large watering cans full of water will do. You’ll need to keep this up for the first two weeks.
  • The second two weeks, you can switch to watering every three days with the above method.
  • After the first month, water once a week unless it is dry and hot (no rain and temperatures above 80 degrees). If it is hot and dry, water twice a week.
  • After the first six months, the trees will be established and won’t need any extra water.


  • Thuja ‘Green Giant’ should not need any extra fertilizer unless your entire lawn and garden has problems and needs regular fertilizing.


  • You won’t have to prune this tree if you are growing it with enough space for it to maintain its naturally graceful pyramid shape. If you’re growing several of these close together as a hedge, you can shear the plants yearly after the final frost, but it is better to plant a shorter, narrower plant that you don’t have to contain.

Because of its ease of care and maintenance, Thuja ‘Green Giant’ is a perfect choice for any homeowner who needs a fast-growing evergreen tree for privacy.

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