A noxious weed is defined by State law as "...any plant species which is, or which may likely to become, injurious, harmful, or deleterious to the agricultural, horticultural, aquacultural, or livestock industry of the State and to forest and recreational areas and conservation districts of the State, as determined and designated by the Department (of Agriculture) from time to time."
Currently, 79 species of plants are designated as noxious weeds. Among the more serious are gorse, banana poka, miconia and ivy gourd. All four weeds are a threat to agriculture and the native forests. Miconia, for example, now covers two-thirds of Tahiti following its introduction in 1937. The same can happen in Hawaii.
Many weed problems arise from the purposeful introduction of plants. Due to Hawaii's year round balmy climate, many plants that are not problematic in other areas can become serious weed pests in Hawaii.
For common weed problems in lawns and gardens, call the University of Hawaii's Cooperative Extension Service at (808) 453-6055. If you would like to know more about noxious weeds, please contact the Hawaii Department of Agriculture Plant Pest Control Branch.