Family: Ranunculaceae

Clematis terniflora, commonly known as sweet autumn clematis or Japanese clematis, is a fast-growing, woody vine native to eastern Asia, including Japan, China, and Korea. It is often grown as an ornamental for its vigorous climbing habit and masses of small, star-shaped white flowers that bloom in late summer to fall with a strong, sweet fragrance. The vine readily covers fences, trellises, and arbors, and produces showy, fluffy seed heads after flowering. Its rapid growth and ease of cultivation have made it a popular landscape plant in many regions.

However, sweet autumn clematis is highly aggressive and poses a serious threat to natural ecosystems when it escapes cultivation. It spreads rapidly by seed, forming dense growth that smothers native plants, blocks sunlight, and overwhelms shrubs and trees along forest edges, roadsides, and disturbed areas. Once established, it is difficult to control and can significantly reduce native plant diversity and habitat quality. Because of its invasive behavior, planting sweet autumn clematis is strongly discouraged, especially near natural areas. Choosing non-invasive vines and ornamentals helps protect Hawaiʻi’s native ecosystems and supports responsible, pono landscaping practices.

High Risk Traits:

• Temperate vine (marginal in subtropics)
  
• Broad climate suitability (in temperate areas)
  
• Widely naturalized
  
• Landscaping and garden weed
  
• An environmental weed
  
• Many Clematis species have become invasive
  
• Unpalatable and presumably toxic to animals
  
• Tolerates many soil types
  
• Shade-tolerant
  
• Overtops and smothers other vegetation
  
• Wind-dispersed seeds
  
• Seeds may be dispersed as a contaminant of mulch
  
• Reaches maturity in 2+ years
  
• Tolerates and resprouts after repeated cutting

Low Risk Traits:

• Temperate climate; may only be a threat to higher elevation areas in tropical islands
  
• Showy flowers
  
• Herbicides may provide effective control