Privet is blooming right now in Kentucky and the scent travels for miles. This Asian native was exported as an ornamental shrub in the early 1800's and it was embraced in many parts of the world. Little did the importers know that the thousands of tiny, black berries the plants produce would be eaten and spread far and wide by birds. This member of the olive family (Oleaceae) has several species in its genus (Ligustrum) and all of them are potentially invasive, although L.sinense and L.japonicum seem to be the worst culprits.
Hardy in USDA zones 6 through 10, privet has spread throughout the Southeast in the US where it sprouts along fence rows and wooded areas and grows at least 15 feet tall when left unpruned. It tolerates shade quite well and even crowds out natives in the understory of the forest. Privet even has a second line of attack, forming dense thickets from clonal suckers sprouting from the roots. This makes it difficult to eradicate and many countries have it listed on their noxious and invasive plant lists. New Zealand and Australia are especially hard hit. The only way to effectively remove it is to dig out the main rootball and systematically cut the suckers to the ground. When they inevitably re-sprout, spraying them with a brush killing chemical may be the only recourse. If all else fails, keeping the plants shaved back so they do not bloom and set seed will prevent more from sprouting and clogging fields and forests.
This evergreen shrub tolerates a wide range of soils and environments and seems to make itself at home just about anywhere. The semi-evergreen leaves are attractive through the winter and unfortunately, this feature helps it remain in the inventories of many nurseries and garden centers. Luckily, there are a few sterile, hybrid cultivars that have been developed, some with golden or variegated foliage, that do not produce seed, so be sure to ask your nursery professional for these selections.
Although it has been used for centuries in Asian medicine as an antiseptic or antibacterial, the berries are poisonous and should be handled with care. There are even reports of fatalities in children who have consumed them, so if you have little ones, it might be wise to remove these plants from your yard. The pollen might be irritable for those with allergies and the heavy, cloying scent of the flowers can cause distress for those who can't tolerate heavy fragrances. I can attest to the fact that even one plant, several fields away can perfume the whole neighborhood, so one near a door or window can invade your home with an unending floral avalanche. In moderation, the scent is quite pleasant, but grows old quickly.
Blindly purchasing plants without taking time to learn about their potential impact on the environment is something that gardeners can no longer do. We have a responsibility to limit potentially harmful or invasive plants in our neighborhoods and by educating ourselves, we become better stewards of the land. It is much better to stick with native selections, such as our native hollies, instead of exotics like the privet. You are helping balance the ecosystem and chances are good the natives are a food and host source for butterflies that need specific plants for their caterpillars. Do your part and think before you buy.