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Ligustrum or Privet1
James T. Midcap, Robert J. Black, Sylvester A. Rose2Evergreen ligustrum shrubs and trees thrive throughout the state of Florida. They are widely used as landscape shrubs, hedges, and specimen trees. Many species and cultivars are available with a diversity of leaf colors, leaf forms, and growth habits. All selections are tolerant of heavy pruning, which makes them suited for clipped hedges. Because of a rapid growth rate, many require pruning to maintain them within bounds. The white flowers are attractive during late spring and early summer. However, the pungent odor may be objectionable.
The most common ligustrums grown in Florida are Japanese or wax privet (Ligustrum japonicum), glossy privet (L. lucidum), and Chinese privet (L. sinense). Japanese privet and glossy privet are easily confused. Japanese privet has thick, evergreen, glossy leaves three to four inches (7.5 to 10 cm) long. The leaves have four to five pairs of veins, and leaf tips have a wide-angled, blunt point. Japanese privet is a vigorous, compact shrub or small tree reaching a maximum height of 15 to 18 feet (4.5 to 5.5 m), but it is easily pruned to maintain desired height. Some available cultivars of Japanese privet are: `Erecta,' `Gold Tip,' `Howardi,' `Nobile,' and `Variegatum.' A slow-growing, round-leaf, upright variety of Japanese privet, Ligustrum japonicum var. roundifolium also called L. recurvifolium, is also available.
Glossy privet (L. lucidum) and Chinese privet (L. sinense) are reported by the Florida Exotic Pest Council to be invasive and could seed themselves and reproduce in nearby landscapes, woodlands, or natural plant communities on conservation lands.
Glossy privet (L. lucidum) grows rapidly and can become a small tree 30 to 40 feet (9 to 12 m) tall. The dark evergreen leaves are four to six inches (10 to 15 cm) long, with six to eight pairs of veins and narrow, elongated tips. Small white flowers are borne in compact terminal clusters in spring. The small, mature, black berries persist much of the year.
Variegated Chinese privet (L. sinense `Variegata') has small white to yellowish variegated leaves one and one half to three inches (4 to 8 cm) long. The less popular green-leafed Chinese privet (L. sinense) is occasionally planted. The variegated form does develop occasional branches with totally green leaves. These branches should be pruned to maintain a uniform variegated form. Both forms grow rapidly and can become 12 feet tall and 10 feet wide. However, Chinese privet is extremely tolerant of pruning and can be maintained at the desired height and spread with regular pruning. The four-inch (10 cm) terminal clusters of flowers produced in April are nearly invisible against the background of variegated foliage.
Use
Ligustrums are some of the most commonly used landscape plants. Their low cost, availability, rapid growth, and wide adaptability to most habitats contribute to their overuse. Ligustrums are used as foundation plantings, hedges, shrub borders, accent shrubs, specimens, and patio trees. Most ligustrums are not well suited for home foundation plantings because of their rapid growth and large ultimate size. Frequent and severe pruning is necessary to prevent these shrubs from obscuring windows and overgrowing allotted areas.Ligustrums are ideally suited for formal or informal hedges because of their large mass of foliage and ability to tolerate heavy shearing as well as neglect. Hedge plants should be spaced two feet (61 cm) apart for low formal hedges and four feet (1.2 m) or more for medium to tall formal or informal hedges. The variegated leaf forms should be used with restraint as hedge or border plants due to their overpowering accenting influence. These variegated forms can be used as accents when planted singly or as small groups. Japanese and glossy privet are prized as multiple stemmed patio and specimen trees. Specimen trees can be maintained in large containers with dramatic effects.
Privets can be planted throughout Florida with little fear of cold injury. They are tolerant of the wide diversity of Florida's native soils and can be grown in full sun to partial shade. Japanese and glossy privet are moderately salt tolerant but should not be used where subjected directly to salt spray. Variegated Chinese privet is not salt tolerant.
Care
Selection of healthy, vigorous plants and proper installation are the first steps in minimizing maintenance requirements. Regular pruning is required to promote desired growth and maintain desired size. Information on plant selection, plant establishment, and pruning is available in the following publications. These publications are available from your Florida Cooperative Extension Service Office: "Selecting and Planting Trees and Shrubs" (Circular 858 ) and "Pruning Landscape Trees and Shrubs" (Circular 853 ).Fertilization of ligustrum depends upon plant size and desired rate of growth. Established plants should be fertilized two to three times a year. Early spring and fall would be best for two fertilizations. A third application can be made during the summer for more rapid growth or for unhealthy plants. A 15-5-10 or 15-5-15 fertilizer can be broadcasted in shrub beds at 0.7 pounds/100 square feet.
Propagation
Ligustrums can be propagated by cuttings, grafting, and seed. Selections must be propagated by cuttings or grafting to maintain the desired leaf and growth characteristics. Softwood and spring hardwood cuttings of most ligustrums root easily. About eight weeks are required for rooting. Glossy privet may be difficult to root at times. Actively growing terminal cuttings root best. Japanese privet and glossy privet are sometimes grafted on Quihou privet to gain nematode resistance.Japanese and glossy privet can be propagated from seed. They flower in late spring or summer with the fruit ripening in September or October. The pulp should be removed and the seed planted without allowing complete drying.
Pests
Aphids, scales, whiteflies, and spidermites commonly attack ligustrums. Aphids or plant lice are small, soft-bodied insects that usually attack young, tender growth at the shoot tip. They suck plant juices and can cause new leaves to curl. Aphids are green, reddish, or black. Insecticides should be applied when populations begin to build and before the leaves curl.Many different kinds of scale attack these ornamentals. Most scale insects attach themselves to leaf undersurfaces and stems soon after hatching and rarely move from their initial feeding site. Scale insects feed by inserting a tiny beak into the plant and sucking plant juices. Inspect plants thoroughly, since scale infestations occur on the undersurfaces of the older leaves first. Spray applications are most effective on small populations of young scales. Egg hatch is closely correlated with the spring flush of new growth. Infested plants should be sprayed after the new growth hardens.
Whitefly adults are small, white winged insects that are readily seen flying about when plant foliage is shaken. The small larvae found on the leaf undersurface are flat, circular, nearly translucent discs. New hatchings of whitefly eggs usually occur in March-April, June-July, and September-October. Two insecticide applications should be applied 10-14 days apart for control.
Spidermites are extremely small and multiply rapidly on leaf undersurfaces. Severe injury can easily occur before spidermites are detected. Injury appears as a bronzing or rust discoloration of the upper leaf surface. Spidermite infections can be verified by placing a white paper beneath the leaves and tapping foliage. The fallen mites can be seen on the paper as small, moving red or brown specks. Two miticide applications five to seven days apart will provide acceptable control.
Nematodes are damaging pests on ligustrum. They are small microscopic round worms that attack plant roots. Large populations damage root systems, reducing plant growth, increasing wilting, and causing nutrient deficiency symptoms, leaf drop, and ultimately death. Attacked roots may form galls, stubby roots, or lesions. Control measures on established plants are limited. Plants grafted on Ligustrum quihoui are resistant to nematode attack.
Leaf spot and root rot diseases attack ligustrum. Leaf spot fungi attack leaves and can cause premature leaf drop. The disease spots are usually light to dark brown with a yellow border. Control measures include destroying infected leaves and applying fungicide. Both are necessary for control.
Ligustrum root rot can be caused by several disease organisms. Infected plants may become unhealthy, making little growth, and/or part or all the plant will suddenly wilt and die. Examination of the root system reveals few if any remaining healthy, white functional roots. No control measures are effective once the plant is infected.
Pest control recommendations for approved insecticides, fungicides, and miticides are available from your Florida cooperative extension service.
Footnotes
1. This document is Fact Sheet ENH-45, a series of the Environmental Horticulture Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. First published: June 1990. Reviewed/revised: March 1991, October 2003. Please visit the EDIS website at http://edis.ifas.ufl.edu2. James T. Midcap, former extension ornamentals specialist; Robert J. Black, extension urban horticulturalist; Sylvester A. Rose, extension ornamentals agent, Environmental Horticulture Department, Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL 32611.
The Institute of Food and Agricultural Sciences (IFAS) is an Equal Opportunity Institution authorized to provide research, educational information and other services only to individuals and institutions that function with non-discrimination with respect to race, creed, color, religion, age, disability, sex, sexual orientation, marital status, national origin, political opinions or affiliations. For more information on obtaining other extension publications, contact your county Cooperative Extension service.
U.S. Department of Agriculture, Cooperative Extension Service, University of Florida, IFAS, Florida A. & M. University Cooperative Extension Program, and Boards of County Commissioners Cooperating. Larry Arrington, Dean.
Copyright Information
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