Weed Control

Avoid planting invasive species in Hawaii.

One of the major threats to Hawaii’s native plants and wildlife is the spread of invasive alien species. These plants displace Hawaii’s distinctive native flora because they have the ability to spread easily, reproduce quickly and grow fast, often shading out native plants that can’t compete. The sad consequence is the loss of diverse native forests that support a large array of unique native plants and animals. Also, poor weed control can become a fire hazard.

Don’t Plant a Pest

It is tempting to think that planting a beautiful tree or shrub in one’s backyard, along the street, or in an agricultural lot is harmless. The fact is, many ornamental plants, which can be purchased at your local garden center or nursery can become terrible pests once they escape into the wild. Birds can eat their seeds and spread them into our native forests. Don’t put these plants in your garden. If you have them now, consider removing them. In fact, the ornamental plant trade accounts for the majority of invasive plant introductions to Hawaii. This single pathway of entry accounts for approximately 70% of all documented invasive plant species in Hawaii.

It only takes one

The multi-million dollar control effort against miconia (Miconia calvescens) was necessitated by the actions of only one or a few individuals who decided to introduce this invasive pest to Hawaii. This is why consciously landscaping our backyards with either natives or non-invasive alien plants is such an important part of conservation in Hawaii.

Be on the look out

You can have another important impact on the war against invasive alien pests.

  • If you see invasive alien pests - report it to the Pest Hotline (808) 643-7378
  • When hiking in our forests, brush your boots (to keep them free of unwanted seeds)
  • When you travel, take care not to bring pests back to Hawaii or between islands.
  • Remind others of these important guidelines.

Ornamentals NOT to use

  • Acacia’s (Australian Acacia, Australian blackwood, gum Arabic tree, sweet acacia)
  • African tulip tree (Spathodea campanulata)
  • Australian tree fern Sphaeropteris cooperi (formerly Cyathea cooperi)
  • Cinnamomum spp. (camphor tree, cinnamon tree)
  • Fiddlewood (Citharexylum spinosum)
  • Guava’s (Psidium spp.)
  • Lantana (Lantana camara, Lantana montevidensis)
  • Non-native fan palms (Washingtonia spp.)
  • Paper bark tree (Melaleuca quinquenervia)
  • Surinam cherry (Eugenia uniflora)
  • White ginger (Hedychium coronarium)

Additional Resources

Source: "Hawaii Backyard Conservation" (PDF), The U.S. Department of Agriculture.

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