The genus Elaeagnus, commonly known as silverthorn or Russian olive, includes several species of shrubs and small trees valued in landscaping for their hardiness and rapid development. These plants are often selected to quickly establish dense privacy screens or hedges. While classified as fast growers, their actual annual increase in size is dependent on both genetics and external conditions. Growth can range from moderate to accelerated based on cultivation methods.
Quantifying the Typical Growth Rate
Elaeagnus species are categorized as fast-growing shrubs, typically adding substantial new growth each year under favorable conditions. For most ornamental varieties, the expected annual vertical growth rate ranges from 1 to 3 feet. Under optimal conditions—including rich soil, consistent moisture, and abundant sunlight—some specimens may surpass the 3-foot annual mark. In less-than-ideal environments, such as heavily shaded locations or poor, compacted soil, the growth rate may slow considerably, sometimes dropping below one foot per year. The classification of “fast-growing” indicates the plant’s capacity for rapid development rather than a guaranteed yearly increase.
Key Environmental Factors Driving Growth
Sunlight
Sunlight is a primary driver of acceleration. These plants perform best and exhibit their highest growth rates when they receive full sun exposure (six or more hours of direct sunlight daily). Sufficient light maximizes the plant’s photosynthetic output, providing the energy needed for rapid growth. When grown in partial shade, the plant’s growth often becomes spindly or “leggy” as it stretches to find more light, and the overall volume of biomass added each season decreases significantly.
Soil Characteristics
Soil characteristics also play a significant role in modulating the plant’s growth potential. While Elaeagnus can survive in poor, alkaline, or saline soils, maximum annual growth occurs in deep, well-drained loamy soils. Optimal soil provides the stable structure for root development and necessary nutrient retention. Poorly draining or excessively compacted soils restrict root expansion and nutrient uptake, which directly slows the plant’s development.
Water Availability
Water availability is the third major factor influencing the rate of growth. Although Elaeagnus is valued for its drought tolerance once established, consistent moisture is required to fuel its most rapid growth. Plants that experience prolonged periods of dryness will naturally slow their growth to conserve resources. Providing adequate and consistent irrigation, especially during the first few years after planting, directly correlates with achieving the upper end of the expected annual growth rate.
Species-Specific Growth Variations
The overall growth potential varies considerably within the genus Elaeagnus, as different species exhibit distinct growth habits and inherent rates. Elaeagnus pungens, or silverthorn, is often the fastest-growing variety for dense hedging applications. It naturally exhibits a dense, multi-stemmed, and spreading habit that quickly fills a space both vertically and horizontally. Its tendency to produce numerous side branches contributes to a rapid increase in overall plant volume.
In contrast, Elaeagnus angustifolia, the Russian olive, typically develops into a small tree rather than a dense shrub. While capable of rapid height gain in its youth, its ultimate growth habit is more open and less dense than the silverthorn. Elaeagnus x ebbingei is known for its excellent salt and wind tolerance and exhibits a vigorous, but slightly more moderate, growth rate compared to E. pungens. Selecting the appropriate species is important for achieving a desired growth outcome.
Managing and Directing Growth Through Pruning
The plant’s inherent growth rate can be significantly influenced by manual intervention, primarily through the use of specific pruning techniques. Pruning is not just a method for shaping the plant but is a direct stimulus for new growth and increased density. Strategic cuts, known as heading cuts, remove the terminal bud, which releases the lateral buds below and encourages the plant to branch out, resulting in a fuller, denser structure.
This technique redirects the plant’s energy from vertical height gain to lateral shoot proliferation, effectively increasing the visual barrier’s thickness. The timing of pruning also impacts the growth outcome, with late winter or early spring often being the preferred time for major structural work. Fertilization can also accelerate the growth rate by providing the necessary building blocks for new tissue production. Applying a balanced, slow-release fertilizer that is relatively high in nitrogen supports the rapid vegetative growth desired for quick screens.