Privet refers to plants in the genus Ligustrum. They are used as hedges so often in the UK that the word "privet" has become synonymous with hedges. Privet types are adapted to most parts of the British Isles, but not all types will grow well in all locations. Be sure the type of privet you are planting is suitable for growing in your region.
Types of privet
Although there are many types of privets, the types most often grown in the UK. are the compact Japanese privet (Ligustrum japonicum), with 2- to 4-inch-long leathery leaves and a rapid growth rate; the California privet (Ligustrum ovalifolium), which is a fast-growing semi-evergreen that spreads by underground suckers and requires frequent pruning; or the variegated Chinese privet (Ligustrum sinense 'Variegata') that has attractive variegated leaves with cream-coloured margins. Other types of privet commonly grown in the U.S. are the regal privet (Ligustrum obtusifolium), glossy privet (Ligustrum lucidum), Amur privet (Ligustrum amurense) and Vicary golden privet (Ligustrum vicaryi).
When to plant privet
Privet most often is obtained by buying container-grown plants. They can be planted anytime of the year. The best time to plant is in the autumn in most parts of the UK, and in the spring as soon as the ground can be worked in areas where the ground freezes. Bare-root specimens most often are planted in the spring. If transplanting privet from one location to another, transplant when the plants are dormant in winter or very early spring. They should be dug from the ground with as much of the root system intact as possible.
How to plant privet
Privet grows best in a sunny location with exposure to at least six hours of direct sunlight each day, although it can tolerate as little as four hours of sunlight. Avoid a full-shade location. The main requirement for growing privet is well-drained soil. Privet is adapted to most soils as long as sufficient moisture is provided during dry weather. Choose a variety that is adapted to your region. For hedges, space the privet according to the mature size of the variety. While some varieties can be planted as close as 45 cm (18 inches), others must be planted as far apart as 1.5 m (5 feet) to avoid diseases caused by poor air circulation. Always plant privet at the same depth it was planted in its previous location. A 2.5 to 5 cm (1 to 2 inch) layer of compost followed by a 5 to 7.5 cm (2 to 3 inch) layer of mulch around the base of the plants conserves moisture and prevents weeds.
Privet plants grown as single specimens often are pruned into the shape of a small tree by removing two-thirds of the lower branches and selectively removing top branches as needed. Privet grown as a hedge is cut back to 15 cm (6 inches) after planting, then cut back to 30 cm (12 inches) in the early autumn. The second summer they are cut back to 45 cm (18 inches), then pruned as needed once or twice a year to create the desired shape. To prevent woodiness at the bottom of the hedge, keep the bottom of the hedge slightly wider than the top to allow sunlight to reach the lower growth.