The classic shrub used to create dense, formal-clipped hedges, privets belong to the botanical genus Ligustrum, which includes about 50 species. Among the many privets available to gardeners are those that are winter deciduous or evergreen. Usually the foliage is the most attractive ornamental feature, although the clusters of tiny white flowers in spring or summer are nice as long as they don't produce an offensive fragrance. Grow all privets in well-drained soil with moderate fertility. Plants survive in full sun to heavy shade, some species and cultivars better than others.
In colder winter areas, such as in U.S. Department of Agriculture plant hardiness zones 3 through 7, Amur privet (Ligustrum amurense) and border privet (L. obtusifolium) are most commonly used. Common privet (L. vulgare) and California privet (L. ovalifolium) grow best in milder temperate zones, zones 5b to 8. In the mildest winter areas of the western and southern United States, zones 7 through 10, gardeners usually grow Chinese/glossy privet (L. lucidum), Japanese privet (L. japonicum) and Chinese privet (L. sinense).
All privets mentioned develop their best shape, leaf density and flowering if grown in full to partial sun situations. They will also grow in partial shade, but if the light is too limited, branches become leggy and leaves spaced more sparsely. Growth rate and flowering diminishes in overly shaded conditions. Of those privets commonly planted in the U.S., glossy privet, Japanese privet and Chinese privet are most tolerant of heavy shade landscape locations.
Privet species that include variegated leaf cultivars do best when not grown in shady conditions. Full to partial sun exposures ensure the cream or yellow pigments in the leaves are most striking and healthy. Low light causes the green areas of variegated foliage to expand to ensure ample photosynthesis occurs to keep the overall plant growing. As with any other plant, inadequate light increases chances for aphid infestations on new growth, which can lead to sooty mold and powdery mildew on leaves from the honeydew excrement left by the aphids.
All privets will grow in shade, but the overall performance of the shrubs will be markedly reduced. Expect plants to grow toward the light source with their new growth each spring, and lower parts of the shrubs to become devoid of leaves. If possible, remove the lower branches of nearby trees to allow more light to shine onto the privets anytime of day. Invasive privet species, such as the Chinese and glossy privets, may do quite well, but gardeners must take care if the plants have enough light to flower and produce the seeded berries. Birds eat and scatter the seeds across the garden, leading to lots of weedy seedlings. Those seedlings in ample light will grow particularly fast and bloom and yield more seeds in future years.