A shrub is a woody plant, smaller than a tree, that typically features multiple stems branching out near the ground, providing structure and texture to a landscape. Homeowners and landscapers seek rapid-growing varieties for practical needs, such as quickly establishing privacy screens, defining property boundaries, or creating windbreaks. The accelerated growth rate reduces the waiting period for a mature landscape, delivering visible, functional results within a few growing seasons.
How Growth Rate Is Measured
A shrub’s growth speed is quantified by measuring the average annual increase in height or spread under optimal conditions. This measurement is expressed in feet or inches per year and is used for classification. Slow-growing shrubs add less than 12 inches per year, while medium-growing shrubs add between one and two feet annually. A plant is classified as “fast-growing” when it consistently adds two feet or more of new growth within a single season. The most vigorous growers can reach rates of three to five feet of vertical growth per year.
Specific Shrubs Known for Rapid Growth
Among the most celebrated rapid growers are those used primarily for dense, quick screening.
Screening Shrubs
- Green Giant Arborvitae (Thuja ‘Green Giant’): This hybrid evergreen is one of the fastest available, frequently adding three to five feet of height each year. Its speed and resistance to deer and disease make it a top choice for establishing a tall, solid, year-round privacy barrier in a short period.
- Wax Leaf Privet (Ligustrum japonicum): This plant can gain two to four feet annually, quickly forming a dense, glossy-leaved hedge. This variety is highly amenable to shearing, allowing for the creation of formal, geometric boundaries in a landscape design.
- English Laurel (Prunus laurocerasus): Growing between one and three feet per year, this popular option offers large, dark green foliage that provides a dense visual block. Its vigorous nature means it reaches mature size quickly, making it a favorite for establishing perimeter hedges, though it demands consistent pruning to maintain its size and shape.
Ornamental Shrubs
Other fast-growing shrubs focus on ornamental appeal rather than year-round screening.
- Red Twig Dogwood (Cornus sericea): This deciduous shrub typically adds one to two feet per year and is prized for its bright red stems that offer striking color in the winter landscape after the leaves have dropped. Because it is a suckering shrub, it spreads quickly, making it effective for mass planting in native or naturalized gardens.
- Crepe Myrtle (Lagerstroemia indica): A standout for rapid ornamental growth with long-lasting flowers, it often grows about two feet per year in warmer climates. It can be maintained as a multi-stemmed shrub or a small tree and is valued for its prolific summer blooms and distinctive exfoliating bark.
Necessary Environmental Conditions for Maximum Speed
Achieving a shrub’s maximum growth potential depends on meeting several environmental requirements that fuel accelerated physiological processes. This includes selecting a species appropriate for the local climate and ensuring it falls within the correct USDA hardiness zone to avoid stunting from extreme temperatures. Most fast-growing shrubs require high light levels, with full sun exposure—at least six hours of direct sunlight daily—necessary to drive the intense photosynthesis required for rapid biomass production. Insufficient light often results in a leggy growth habit and a significantly reduced annual increase.
Soil health is an important factor, as the ground must provide the necessary physical structure and nutrients to support the root system. Optimal drainage is necessary, as fast-growing plants require frequent watering but are highly susceptible to root rot in waterlogged conditions. The soil should be well-amended with organic material, such as compost, during the initial planting to improve structure and provide a consistent source of micronutrients. Providing these ideal conditions ensures the shrub bypasses the prolonged “establishment phase” that often slows down growth.
Pruning and Maintenance Needs of Fast Growers
The speed of these plants dictates a more intensive, ongoing maintenance schedule once they are established. Fast-growing shrubs often require more frequent and sometimes more aggressive pruning to maintain their intended size and shape and prevent them from becoming overgrown or encroaching on structures. For hedges, this often means multiple shearing sessions throughout the growing season. Strategic thinning cuts, which remove entire branches back to a main stem, should be periodically employed to increase air circulation and light penetration into the plant’s core, counteracting the effects of excessive shearing.
Sustaining a high growth rate demands a steady supply of resources, necessitating regular monitoring of watering and nutrient levels. Consistent soil moisture is important, especially during dry periods, to support the high rate of transpiration that accompanies rapid foliage production. Fast growers benefit from a regular feeding schedule with a balanced fertilizer to replace the nutrients continuously used for new growth. For highly vigorous species, such as Privet or some bamboos, vigilance is needed to control potential invasive tendencies or aggressive root systems, which may require installing root barriers or consistently removing suckers to keep the plant contained.