Common privet

Identification and origin

Ligustrum vulgare belongs to the Oleaceae, the olive and lilac family. Its native range runs from northwestern Africa across Europe to northwestern Iran, including Türkiye and the Caucasus. In Britain it grows wild in hedgerows, woodland edges and scrub on well-drained chalky soils. It has naturalized across much of the eastern United States, where it readily escapes from gardens.

It is a dense, multi-stemmed shrub, deciduous or semi-evergreen depending on how harsh the winter is. It reaches 8–13 ft tall and as wide in ten to twenty years, and some plants grow to 16.5 ft. Growth is fast. The thin gray-brown twigs carry small lenticels, and the bark stays thin and smooth.

The opposite, simple leaves are lance-shaped to oval and 1–2 in long. Dark green, leathery and glossy with smooth edges, they sometimes turn purplish in fall. In early summer, terminal panicles 1–3 in long fill with small, tubular, four-lobed white flowers whose powerful scent many people find unpleasant. They attract bees and butterflies. Small black berries about 0 in across follow, ripening in early fall and hanging on the branches well into winter. Birds eat them and spread the seeds.

Common privet is the main food plant of the privet hawk-moth and gives cover to small birds. A few cultivars are grown: ‘Cheyenne’, sold as the hardiest form, which holds its leaves late; ‘Densiflorum’, upright without pruning; ‘Pyramidale’, with a loosely pyramidal habit; and ‘Lodense’, a compact dwarf that barely passes 5 ft after many years. Do not confuse it with California privet, Ligustrum ovalifolium, a Japanese species widely planted for hedges, or with Chinese privet, Ligustrum sinense.

Light

It grows equally well in full sun or partial shade and accepts any exposure, north-facing included. It tolerates windswept sites as well as sheltered gardens, along with urban pollution.

Watering

In the ground, an established plant tolerates drought and copes with soil that is sometimes dry and sometimes moist.

In a container or as a bonsai, the soil reserve is small and needs regular checks. Water thoroughly as soon as the surface of the mix starts to dry, until water runs out of the drainage holes. In hot weather that moment comes much sooner. In winter, water less often, but never let the root ball dry out completely. Very hard water, used continuously, can cause chlorosis, a yellowing of the leaves from nutrient deficiency.

Potting mix

Common privet is very undemanding. It grows in clay, loam, sand or chalk, whether acidic, neutral or alkaline, as long as water drains well. It is in fact common on limestone soils. Only avoid ground where water stands for long periods, which encourages root rot. In a container, a standard well-draining potting mix or bonsai mix is all it needs.

Temperature

The species is hardy in USDA zones 4a to 7b. It withstands winters that drop to around -4–5 °F and suits all of northern Europe. The colder the winter, the more leaves it drops: privet then behaves like a deciduous shrub, with no lasting damage, and new leaves replace the old ones in spring. Even ‘Cheyenne’, reputedly the toughest, can suffer in the coldest parts of zone 4.

In a container, the roots are far more exposed than in the ground. Leave the plant outdoors through fall so it hardens off, then protect the pot once temperatures fall below 14 °F.

Repotting

The shrub transplants easily. In a container, repot every two to three years in spring, as the buds begin to extend. Privet tolerates root pruning well: shorten the longest roots and replace part of the mix.

Pruning

Few shrubs take pruning better, even hard pruning: it regrows from old wood. For a hedge, formative pruning matters most in the first two years after planting. Let the leading shoot grow and shorten overlong side shoots in spring to thicken the base. After that, a formal hedge is trimmed two or three times during the growing season, removing nearly all of the year’s growth. Before each trim, check for bird nests, which are common in spring and summer.

On a free-standing shrub, prune after flowering. Next year’s flowers form on new growth, so late pruning reduces flowering. Removing spent flowers before berries form keeps birds from spreading the seeds, which helps where the species becomes invasive.

Propagation

Common privet is very easy to propagate. Take semi-ripe cuttings in summer or hardwood cuttings in winter. Air layering works well in late spring. Seed can be sown outdoors in fall or spring, but germination is slow and the plants take longer to develop.

Common problems

It is rarely seriously affected. Watch for aphids, including the privet aphid, scale insects, whiteflies, thrips, weevils and leaf-mining caterpillars that tunnel through the leaves; small mites can also attack it. Diseases include leaf spots, anthracnose with twig dieback, cankers, powdery mildew, Verticillium wilt, honey fungus and root rot in poorly drained soil. Copper deficiency can also occur. A single symptom, such as yellowing or leaf drop, can have several causes: check the soil, the watering and the undersides of the leaves before treating.

Finally, the species self-seeds and naturalizes easily outside gardens, to the point of being considered invasive in parts of North America.

Toxicity

The whole plant is toxic, especially the berries and leaves. In people, eating it can cause abdominal pain, nausea, vomiting, diarrhea, headache, weakness and low blood pressure, and the effects can last two to three days. The black berries, tempting to children, are highly poisonous. The sap does not cause contact dermatitis, but wearing gloves is advised when handling the plant.

Privet is toxic to dogs, cats and horses, and to livestock. It mainly causes digestive upset, sometimes incoordination and a faster heart rate; a large amount can cause serious heart rhythm problems and, rarely, death. If a person or animal eats any part of it, contact a veterinarian or a poison control center right away.