There are many reasons to plant trees for privacy. Let’s say, for instance, that your neighbours have just painted their house a truly unfortunate colour, and no amount of sun over any amount of years will improve it. Maybe the world’s ugliest high-rise is spoiling the view from your patio. Perhaps your bedroom window is right across the street from someone else’s, and you’re fairly certain you caught a glimpse of either a telescope or one of those really long zoom lenses for a camera. These are situations where a nice big tree or two – or more – would be just the thing. The problem is that you might not fancy cowering behind blinds for ten or twenty years waiting for the trees you planted to reach the proper size.Luckily, not all trees grow slowly. There are many trees, available online or in your local garden centre, that grow anywhere from 3 to 15 feet per year. The list below represents just a sampling of such fast growing trees
Thuja Green Giant (Thuja standishii plicata)
This evergreen tree offers year round privacy from the neighbours, and requires very little space. Thuja Green Giant is a living evergreen fence that grows 3 to 5 feet per year once it's established. If any tree could be described as bulletproof, this tree is it. Drought tolerant, insect and disease resistant, it also resists ice and snow damage, and it grows in nearly any type of soil. Although Thuja Green Giant prefers direct sunlight, it also does well in partial shade. The only pruning it needs is for height, because in three years, it will reach 15 to 20 feet in height, and its height at maturity will be anywhere from 20 to 40 feet. To use Thuja Green Giant as a quick privacy hedge or windscreen, plant every 5 to 6 feet, which will allow its mature width of 5-8 feet to fill in any gaps.
Hybrid Willow (Salix matsudana alba)
The Hybrid Willow, also known as the Austree, grows up to 6 feet each year, and quickly fills out to make a solid green wall. It is disease resistant and can handle both hot and cold climates. This deciduous tree thrives in almost any soil and any weather. It is also seriously low-maintenance; all you have to do is plant your trees 5 feet apart, and then forget them. Hybrid Willows typically form a thick green wall by the end of the first full growing season. At maturity, one tree will attain a height of 50-75 feet and a width of 20-30 feet. Planted in rows, each tree will attain the height of 35-45 feet.
Royal Empress Tree (Paulownia elongata)
This deciduous tree provides year round interest. In the winter, its branches are covered with furry, pea sized buds. In the spring, those buds explode with purple blossoms that smell like a cross between gardenia and jasmine.
When summer arrives, the tree forms a dense canopy that could significantly lower your power bills. Its leaves are huge, measuring about a foot wide, and look almost tropical. When the leaves fall in autumn, their large size makes cleanup easy. In addition, larger leaves mean fewer branches, which translates to more sunlight shining through in the winter, when you might need that natural heat the most.
This is one flowering tree that isn’t high maintenance. It grows almost everywhere, but it prefers H5-H1c (USDA zones 7-11). It has no significant insect or disease problems, is drought tolerant, and grows in just about any kind of soil. This hardwood tree grows at a rate of 12-15 feet per year, reaches a height of 40-50 feet and a width of 30-40 feet at maturity, and lives to an old age.
Note: Some tree suppliers use wild seed that doesn't grow as quickly and could be invasive. Others apply growth inhibitors to keep their trees smaller for shipping purposes – inhibitors that can remain in the tree for several months. As will all things gardening, make sure you’re dealing with a reputable nursery.
Leyland Cypress (Cupressus leylandii)
This evergreen tree grows up to 3 to 5 feet per year, features feathery soft, lush foliage, and is drought tolerant. Leyland Cypresses are well known for their iconic columnar silhouettes which, when planted 8 feet apart for a privacy hedge, thicken to create a solid wall.
Despite its rapid growth, the Leyland Cypress can be easily pruned to whatever height or shape you desire. Even without pruning, it will grow in a uniform, symmetrical shape. It is also adaptable to a variety of soils and conditions. At maturity, each tree will reach a height of 40-60 feet, and a width of 20-25 feet.
Autumn Blaze Maple (Acer freemanii 'Autumn Blaze')
This deciduous tree features eye-catching, reliable red fall colour that's rather spectacular. A hybrid of the red and silver maples, the Autumn Blaze Maple combines those two trees' salient characteristics - brilliant red colour and dense branching – with its own rapid growth rate of 3 to 5 feet or more per year.
It is insect and disease resistant, and adapts to a large range of climates and soil conditions. Autumn Blaze Maple is also resistant to ice damage and high winds, doesn’t require much in the way of maintenance, and isn’t bothered by car exhaust, which makes it perfect for planting along busy neighbourhood streets. Its height at maturity will be anywhere from 40 to 50 feet; its width at maturity will be anywhere from 30 to 40 feet.
American Sycamore (Platanus occidentalis)
The American Sycamore grows up to 6 feet per year, eventually reaching a height of 70 feet and a width of 50 feet at maturity. This deciduous tree's many branches develop large green palmate leaves that turn to gold in the fall, and create a thick canopy that provides lots of shade. This variety develops smooth, white bark in the winter, adding additional seasonal interest to the garden. The American Sycamore is surprisingly easy to grow. It adapts to most soils, thrives in both warm and cold climates, and grows just about anywhere, even in harsh environments.
Heritage River Birch (Betula nigra 'Heritage' )
This deciduous tree is resistant to common birch diseases, grows anywhere from 2 to 4 feet per year, adapts to various soil types, both wet and dry planting sites, and tolerates modest drought and mild floods. Heritage River Birch is also resistant to strong wind and ice due to the strength of its limbs and branches. It features unique naturally peeling bark with flecks of salmon or cinnamon under a light taupe outer skin. Due to this unusual bark, the Heritage River Birch provides year round interest in the garden. At maturity, this tree will reach a height of 40-50 feet, and a width of 25-40 feet.