Contact CTAHR Scientists

Ivy gourd, Coccinia grandis

Ivy gourd, Coccinia grandis, is another common weed problem in Hawaii.

Photo: Kim and Forest Starr

Weed Links

Invasive Plants

State of Hawaii Noxious Weeds: from HEAR website.

Hawaii Invasive Species Partnerships: Portal website for the Hawaii Invasive Species Council (HISC), the Coordinating Group on Alien Pest Species (CGAPS), and the Invasive Species Committes for each Hawaiian island.

Hawaii Ecosystems at Risk Project: features invasive species information for Hawaii and the Pacific

Global Invasive Species Database includes descriptions of ecology, distribution, management information, impacts, references and links for 100 of the World's Worst Invasive Alien Species, many of which are found in Hawaii.

Hawaii/Pacific Weed Risk Assessment: Weed risk assessments are used to identify high-risk plant species which are likely to become invasive plant pests. Many species have been screened. Check this database before planting to determine if your plant species may harm Hawaii's environment.

Jumping the Fence Line: Escaped Agricultural Plants in Hawaii: Plants intentionally introduced into the islands of Hawai‘i as crops, livestock forage, ornamentals, and forestry species have escaped cultivation, gone “wild” and now cause economic problems for agricultural producers and land managers. They also take over habitat for rare and endangered native species. Review the Adobe .pdf presentations from the workshop.

Weed Identification

Handbook of Hawaiian Weeds. Edited by E. L. Haselwood and G. G. Motter (1966). Digitized version now available.

Weed Science Hawaiian Style with Dr. Joseph DeFrank: Dr. DeFrank's website which includes a Weed ID Website with color images and scans from the Handbook of Hawaiian Weeds (eds. E.L. Haselwood and G.G. Motter, Univ. of Hawaii Press, © Harold L. Lyon Arboretum, 1983). The color images are designed to complement the description of weeds provided in the handbook.

Pacific Islands Distance Diagnostic and Recommendation System: This site allows free registration and access to Pacific wide diagnostic expertise for identification and recommendations for many crop pests. Digital images can be submitted to identify pests.

Plants of Hawaii. A site for identifying many common plants found in Hawaii. This site contains 8000+ copyright free high resolution images of both native and non-native plants.

Some Common Weeds in Hawaii (Handout from Kahuku Field day) by Jari Sugano, Steve Fukuda, Ted Radovich (.pdf file 2.29MB)

Weed Science Society of America. National organization of weed scientists, also has a weed identification section.

Pesticide Information

CTAHR’S Extension Pesticide Program is CTAHR’s clearinghouse for pesticide use information.

Hawaii Pesticide Information Retrieval System: UH site that contains information pertaining to pesticides currently licensed for distribution and sale in Hawaii.

Hawaii Department of Agriculture: Overview of major regulations affecting pesticide use In Hawaii

Weed Management for Gardeners and Farmers

Weed Management Guide: University of Florida IFAS Extension

Weed Management in Vegetable Crops: University of Florida IFAS Extension. Information on weed control for many vegetables.

Weed Management University of Florida IFAS Extension. A wide collection of Information on weed control for agronomic crops, vegetables and citrus, lawn and garden weeds, nursery-pasture-forest, aquatic weeds, biological control, etc.

University of California IPM. Photos of crop pests and methods to control them.

Organic Weed Control

Weed Management in Organic Agriculture. Presentation by Dr. Ted Radovich (~1MB .pdf).

Flaming for Weed Management on Small Farms. Presentation by Dr. Ted Radovich (~1MB .pdf).

Vinegar for Weed Control: Site maintained by Purdue University for information on using vinegar for organic weed control

Weed Management for Organic and Sustainable Crops: Site contains many links to weed management for organic farmers and those seeking to reduce chemical inputs for weed management.