Chinese privet

Identification and origin

Ligustrum sinense belongs to the Oleaceae, the olive and lilac family. It is native to China (north-central, south-central and southeast), Hainan Island, Taiwan, Tibet and Vietnam. Introduced as an ornamental, it has naturalized in many regions, including the southeastern United States, Central America and Argentina, New Zealand, Réunion, Italy and Spain.

It is a rounded, mounding, spreading shrub that reaches 6–15 ft tall and as wide in cultivation. In the wild it can become a large shrub or small tree of 10–39.5 ft, often with several clumped, leaning trunks. It grows fast.

• Leaves: opposite, simple, elliptic to oblong, with smooth edges, glossy dark green, 1–3 in long and 1–1 in wide. The undersides and leaf stalks are hairy.
• Twigs: grayish-yellow and hairy, with conspicuous lenticels.
• Flowers: small and creamy white, in panicles at the branch tips in late spring or early summer. They are scented, but many people find the smell unpleasant.
• Fruit: small black drupes that look like tiny olives, 0–0 in across, in clusters that ripen from late summer into fall. Each holds one or two seeds.

Depending on drought, shade and temperature, the foliage stays on all winter or partly drops, so the species is described as deciduous by some and evergreen by others. It is less deciduous than European privet. Several cultivars exist, such as ‘Sunshine’, compact with yellow foliage, and ‘Swift Creek’ and ‘Variegatum’, with variegated leaves.

Light

Chinese privet grows in full sun to part shade. It tolerates shade well: seedlings can hang on even under a dense canopy, but they only persist a few years unless the canopy opens up. In a container, and especially as a bonsai, give it a bright spot with direct sun for at least part of the day to keep the growth dense.

Watering

Once established, the shrub is fairly drought tolerant, but it grows best in moist, well-drained soil. It copes with brief flooding, not with soil that stays waterlogged.

In a pot, check the soil instead of following a schedule: water thoroughly as soon as the surface dries, which can happen very quickly in hot weather. In winter, water much less often, but never let the root ball dry out completely. Very hard water can cause chlorosis, a yellowing of the leaves.

Potting mix

In the ground it adapts to a wide range of soils, including poor or alkaline ones above pH 8, and needs little fertility. Its only real dislike is poorly drained soil. In a container, a standard free-draining potting mix works; for a bonsai, a regular bonsai mix is enough.

Temperature

Chinese privet is hardy in USDA zones 6a to 9b, which means winter lows of about -9 °F. Cold weather makes some leaves drop, more so as temperatures fall, but without lasting harm: new foliage replaces them in spring. In a container, protect the root ball when temperatures drop below 14 °F.

It is often sold as an indoor bonsai. A plant grown in the house should stay inside until spring; one meant to spend the winter outdoors should go out in fall so it can harden off.

Repotting

In the ground, its root system is extensive and shallow, and it suckers readily, especially after root damage. Seedlings can only be pulled out successfully if the whole root comes with them.

In containers, repot every two or three years in spring, as the buds extend; young, vigorous bonsai can be repotted every year. The shrub takes root pruning well.

Pruning

Chinese privet takes pruning very well and grows back vigorously, even from the root crown after severe cutting. It therefore needs regular trimming to stay compact.

• Hard pruning: in late winter or early spring, before new growth starts.
• Maintenance trimming: throughout the growing season, shorten overlong shoots and remove oversized leaves.
• Flowering: flowers form on the current season’s growth; to enjoy them, do not trim new shoots before summer.
• Defoliation: the species tolerates it on a vigorous bonsai.

Cutting a shrub down to the ground is not enough to get rid of it: it resprouts from the base.

Propagation

• Cuttings: easy. Semi-ripe cuttings in summer or hardwood cuttings in winter.
• Air layering: in late spring.
• Seed: possible in fall or spring, but germination is slow. Seeds mostly germinate in the season after they are dispersed, best between 59 °F and 77 °F, and do not build up a lasting seed bank in the soil.

In the wild, birds eat the fruit and spread the seeds. Chinese privet then forms dense thickets that crowd out native plants. It is listed as invasive in several states, and planting it in gardens is discouraged in favor of native species.

Common problems

One symptom can have several causes: yellow leaves can come from very hard water, overwatering or too little light. Look at the plant and its growing conditions before treating.

• Insects: whiteflies, aphids, scale (including white peach scale), thrips, leaf miners and weevils, notably the ligustrum weevil.
• Mites: privet rust mite also settles on the foliage.
• Diseases: anthracnose, twig blight, cankers, leaf spot, powdery mildew, wilt and root rot, especially in soil that stays too wet.
• Chlorosis: pale leaves when the irrigation water is very hard.
• Winter leaf drop: normal in cold weather.

Chinese privet resists deer damage.

Toxicity

Privet is toxic to dogs, cats and horses. All parts of the plant contain terpenoid glycosides. Eating it most often causes digestive upset such as vomiting, diarrhea and loss of appetite; a large amount can lead to incoordination, a fast or irregular heart rate and, rarely, death.

In people, toxicity is low. The leaves and fruit contain glycosides, including syringin, and shikimic acid. Eating them can cause abdominal pain, nausea, vomiting, diarrhea, headache, weakness, low blood pressure and cold, clammy skin, for 48 to 72 hours. The small black fruit are moderately poisonous: keep the plant out of reach of children and pets.