Privets are popular landscape shrubs widely used for hedging and screening. Determining their final height depends on two primary factors: the specific variety chosen and the level of maintenance provided. For most landscaping purposes, however, the plant’s height is actively controlled and maintained at a much lower level than its maximum potential.
Common Privet Varieties and Their Mature Heights
The unmanaged height of a privet is dictated by its species, with some varieties capable of reaching significant elevations if left unpruned. The Japanese Privet (Ligustrum japonicum), often called Wax-leaf Privet, is an evergreen variety that typically matures into a large shrub or small tree between 6 to 18 feet tall. Under optimal conditions, some mature specimens of this species may even reach up to 20 feet. Cultivars like ‘Texanum’ offer a more moderate size, usually topping out between 6 and 8 feet, making them suitable for smaller garden spaces.
Another widely planted variety is the California Privet (Ligustrum ovalifolium), which is generally a semi-evergreen shrub that reaches a maximum height of 10 to 15 feet. This species is commonly used for hedges because it responds well to shaping, maintaining a dense, upright form. The Chinese Privet (Ligustrum sinense) has a slightly larger potential, capable of growing as a broadleaf semi-evergreen shrub or small tree, reaching between 10 and 20 feet tall when unmanaged. Dwarf cultivars also exist, such as L. sinense ‘Wimbei,’ which is bred to stay extremely short, maturing at only about 1.6 feet.
Understanding Growth Rate and Spread
Privets are favored for quick privacy screening due to their fast growth habit. Most common privet species are vigorous, easily adding between one and two feet of new growth each year. Japanese Privet, in particular, is frequently cited as adding more than two feet of height annually, allowing a hedge to fill in rapidly.
This rapid growth means that while a desired height is reached quickly, it also requires frequent attention to maintain. The mature spread of unmanaged privets is also substantial, often equaling or exceeding their height. California Privet can grow 10 to 15 feet wide, while Japanese Privet can spread to 15 to 25 feet across, forming a very dense screen.
Height Management Through Pruning
For most landscapes, the actual height of a privet hedge is determined by regular maintenance, requiring active control through pruning and shearing. Privets must be sheared multiple times throughout the growing season to maintain a formal, dense hedge.
A crucial technique for maintaining a privet hedge is to shape it so that the base is slightly wider than the top, creating a subtle ‘A’ shape. This shape ensures that sunlight reaches the lower branches, preventing the bottom of the hedge from becoming sparse and leafless. For height control, a string line can be tied between stakes at the desired maximum elevation, providing a guide for clean, level cuts across the top.
Pruning should generally be done following the plant’s initial flush of growth in the spring, and then again one or more times during the summer to maintain a sharp appearance. Pruning after the small white flowers bloom helps prevent the plant from setting fruit and spreading seeds, which is important for controlling invasive species. If a privet hedge has become severely overgrown, a rejuvenation prune can be performed in late winter, cutting the plant back hard to within 6 to 12 inches of the ground to stimulate new growth.
Environmental Influences on Final Size
The final size a privet achieves can be influenced by local environmental conditions. Privets perform best in full sun, which encourages dense, compact growth. Plants grown in partial or heavy shade often become leggy and sparse, failing to achieve the full, bushy form desired for a hedge.
Soil quality and water availability also play a role in growth rate and ultimate size. While privets tolerate a wide range of soil types, they require well-drained conditions and will not thrive in permanently wet areas. Consistent moisture in a rich soil will allow them to reach the upper limits of their size potential more quickly.