Family: Oleaceae

Origin, Description & Uses
Ligustrum ovalifolium (California privet, garden privet) is a shrub native to Japan. It is widely planted around the world as an ornamental hedge due to its fast growth, dense branching habit, and ability to be easily pruned into formal shapes. The plant is semi-evergreen to evergreen depending on climate, and produces clusters of small white flowers followed by dark berries. Because of its toughness and tolerance of trimming, drought, and a range of soils, it is commonly used for privacy screens, windbreaks, and landscape borders in gardens and urban plantings.

Risks & Threats
Although Ligustrum ovalifolium is currently not known to be naturalized in the Hawaiian Islands, it does possess traits that are cause for concern, and which could detrimentally impact tropical island ecosystems. In other regions, privet species are known to escape cultivation and spread through bird-dispersed seeds, forming dense thickets that crowd out native vegetation and reduce biodiversity. Its vigorous growth, shade tolerance, and ability to resprout after cutting make it difficult to control once established. If introduced into natural areas, it could alter habitat structure and compete with native plants for light, water, and nutrients. Given these risks, it is recommended to choose a low-risk or native alternative for hedges and landscaping in Hawaiʻi, such as ʻaʻaliʻi (Dodonaea viscosa), naio (Myoporum sandwicense), or other locally appropriate native species.

High Risk Traits:

• Grows in 5 hardiness zones in temperate climates, demonstrating environmental versatility
  
• Naturalized in the continental United States and New Zealand (but no evidence in Hawaiian Islands to date)
  
• A disturbance-adapted weed on the mainland US
  
• Other Ligustrum species are invasive
  
• Toxic to animals and people
  
• Shade-tolerant
  
• Tolerates many soil types
  
• Forms dense stands, excluding other vegetation
  
• Reproduces by seeds and vegetatively by suckering
  
• Self-compatible
  
• Seeds dispersed by birds, other frugivorous animals and intentionally by people
  
• Able to resprout from cut stumps

Low Risk Traits:

• Unarmed (no spines, thorns, or burrs)
  
• Browsed by deer (palatable despite reports of toxicity)
  
• Ornamental
  
• Herbicides may provide effective control