Family: Meliaceae

Azadirachta indica (neem) is a fast-growing evergreen tree native to the Indian subcontinent and widely planted throughout the tropics for its traditional medicinal uses, durable wood, and insect-repellent properties. In Hawaiʻi, neem has been cultivated in home gardens and small farms, where it is valued for its hardy growth and low water needs. However, it has shown the ability to escape cultivation, and it is naturalized on O‘ahu, where seedlings establish readily in disturbed areas.

Although neem offers various cultural and practical benefits, it also possesses traits associated with invasiveness, including prolific seed production and tolerance of poor soils and dry conditions. These characteristics can allow it to spread into natural or semi-natural habitats, where it may compete with native species. As a result, neem is rated High Risk by the Hawaiʻi Pacific Weed Risk Assessment. Plant Pono recommends exercising caution and considering non-invasive alternatives for landscaping or agricultural use.

High Risk Traits:

• Tolerates wide soil and climate ranges
  
• Naturalized in Australia, Africa, Southeast Asia, Hawaii
  
• Forms dense thickets that reduce biodiversity
  
• Prolific seed production (44,000–200,000 seeds/year)
  
• Bird, bat, and water-dispersed seeds
  
• Resprouts after cutting or fire
  
• Allelopathic potential
  
• Shade tolerant
  
• Repeatedly introduced worldwide

Low Risk Traits:

• Non-toxic to humans and animals
  
• No spines or thorns
  
• Limited vegetative spread
  
• Short seed viability (weeks)
  
• Not a produce contaminant
  
• Not wind-dispersed
  
• Self-incompatible (needs cross-pollination)
  
• Controlled by herbicides