Problems with privet hedges
Privets (Ligustrum spp.) are evergreen, fast-growing shrubs introduced to the United States as an ideal hedge plant. Privets handle frequent pruning or even being cut back to the ground, enhancing their survivability as a hedge.
However, the problems with maintaining privet hedges indicate that a different species or a mixture of plants should be used in place of a solid privet hedge.
Needs Frequent Pruning
Privets, especially Amur privets (Ligustrum amurense), are prized for growing in quickly and somewhat densely as hedges. But this same attribute means that they get shaggy quickly and must be pruned frequently to stay looking tidy. Very formal hedge shapes, such as box privet hedges, suffer most from this problem, since more naturally shaped hedges have no unnatural flat sides of which new growth takes advantage.
Winter Kills and Lackluster Appearance
Privet varieties vary in winter hardiness, and winter kills (the death of some of the privets in a hedge) don't repair easily in hedges. Likewise, the fact that hedges are usually butted up against little more than concrete or the edge of the lawn means that a hedge of privets is extremely exposed to an unusually cold snap. The leaves of privet hedges don't display any lovely fall colours, and they tend to thin out unattractively in winter. The underlying privet form is twiggy and lacks winter interest.
Weedy or Invasive
Privets offer food for birds in the form of their small berries. But the birds distribute the seeds in the berries, and privets have started coming up in places where they're destructive toward or crowd out native species. European privet, border privet, California privet and Chinese privet are considered noxious exotic pestilent plants in certain U.S. states.
Variegated varieties of privets are not entirely stable. While an occasional branch of solid green in an otherwise variegated bush can be handled with little problem, cutting holes in the face of a hedge to rid each bush of its reverted green branches adds to maintenance and detracts from the appeal of the planting. Seeds of variegated varieties also tend to produce solid green privets.
Attractive to Bees
Privets bloom with profuse, albeit hidden, bunches of tiny white flowers. While this doesn't add much visual interest for people, it's a magnet to bees. A privet hedge can become a bee highway. While this usually isn't a problem, small children and pets that don't yet know how to handle bees should be kept away from privet hedges.