Homeowners and developers often seek out fast-growing trees to fulfill the immediate need for benefits like quick shade, increased property privacy, or acting as an effective windbreak much sooner than their slower-paced counterparts. Their appeal lies in accelerating horticultural results, transforming a newly planted yard into an established space quickly. However, this speed of growth represents a biological trade-off that requires careful consideration beyond the initial planting choice.
Criteria for Defining Fast Growth
Arborists and horticulturists categorize tree growth rates based on the average annual increase in height under optimal growing conditions. This classification provides an objective metric for comparing different species. A tree is generally classified as having a slow growth rate if it adds 12 inches or less to its height each year.
Species with a medium growth rate typically gain between 13 and 24 inches in height annually. To be formally categorized as a fast-growing tree, a species must exhibit an annual height increase of 25 inches or more. This determination is based on the vertical growth of the main trunk and branches, not the spread of the canopy.
These are average rates, and a tree’s actual performance is heavily influenced by site-specific factors. Soil quality, water availability, climate, and sunlight can all cause a tree to grow faster or slower than its published average. The “fast” label is strictly a measure of potential vertical gain over a year’s time.
Popular Examples of Quick-Growing Species
Many popular selections are prized for their rapid vertical growth, making them suitable for specific landscape objectives. The Hybrid Poplar, a cross between North American and European species, is among the fastest, capable of adding five to eight feet in height during a single growing season. This rapid pace makes it a frequent choice for creating quick shade and establishing tall boundary screens.
Another highly effective option for rapid screening is the Thuja Green Giant, a vigorous evergreen that can grow three to five feet per year. Its dense, conical form allows it to quickly establish an effective, year-round privacy barrier. The Weeping Willow is also a quick grower, often gaining four to eight feet annually, and is frequently planted near water features where its extensive root system can access abundant moisture.
For deciduous shade, the Red Maple, particularly some hybrid cultivars like ‘Autumn Blaze,’ can achieve growth rates of up to three feet per year. This makes it a favored option for homeowners seeking a substantial canopy and vibrant seasonal color relatively quickly. The River Birch, known for its attractive peeling bark, is also considered a quick-growing ornamental tree, typically adding one to three feet of height each season.
Managing the Long-Term Needs of Rapidly Growing Trees
The accelerated growth rate often comes with structural and maintenance considerations. Rapidly produced wood often contains less dense lignin compared to the wood of slow-growing hardwoods, resulting in softer wood that is inherently weaker. This lower density makes the tree more susceptible to failure, especially during high winds, heavy snow, or ice storms.
Many fast-growing species also develop extensive, aggressive, or shallow root systems to support their large canopies. These expansive root networks can easily lift and crack sidewalks, driveways, and foundations, or even invade underground pipes and septic systems if planted too closely to infrastructure. Proper placement, well away from any hardscaping, is therefore paramount.
To mitigate the risk of structural failure, early and consistent structural pruning is a requirement for fast-growing trees. This process, often called formative pruning, focuses on establishing a single dominant trunk, or leader, and balancing the weight of the canopy by reducing the length of heavy side branches. Without this preventative care, the fast-growing trees are prone to developing weak branch unions that are likely to split as the tree matures.
The prioritization of speed over density also contributes to a generally shorter lifespan for many fast-growing species compared to slow-growing oaks or maples. While they offer immediate benefits, many of these trees decline shortly after reaching mature size, often requiring replacement sooner than slower-growing trees. This shorter cycle necessitates a long-term plan for eventual removal and re-planting.