Some Invasive Non-Native Plants to Avoid Using in Landscape and Restoration Projects, a Partial List for the Puget Sound Area

By , Greenbelt Consulting

Most of the problem plants found on Puget Sound shorelines are not native to the area. They have been introduced, either intentionally or unintentionally. They have become established throughout the region due to their aggressive growth patterns, lack of natural controls, and as a result of clearing and grading practices associated with development and urbanization. These plants can spread rapidly into adjacent native plant communities, where they reduce habitat for wildlife, and diminish the ability of the natural environment to perform a wide variety of important ecological functions. They can also spread into roadways, agricultural lands, and managed forests, necessitating the use of herbicides for their control. The list below is not comprehensive. Check with your local Weed Board for more information.

They are often referred to as invasive non-natives, invasive weeds, and exotic plant pests. They should be discouraged, controlled, or eradicated on shoreline properties. These plants should never be intentionally planted as landscape, restoration, or revegetation species, though some may be considered ornamental or landscape plants.

Gorse
Himalaya Blackberry
Mediterranean Sage
Japanese Knotweed
Foxglove
Canadian Thistle
  • Amur maple (Acer ginnala)
  • Bird’s foot trefoil (Lotus corniculatus)
  • Bamboo (Arundinaira, spp.)
  • Bamboo (Bambusa, spp.)
  • Bamboo (Chimonobambusa, spp.)
  • Bamboo (Phyllostachys, spp.)
  • Bamboo (Pseudosa, spp.)
  • Black locust (Robinia pseudoacacia)
  • Butterfly-bush (Buddleja davidii)
  • Canada thistle (Cirsium Arvense)
  • Creeping charlie, Ground ivy (Glechoma hederaceae)
  • Daphne (Daphne laureola)
  • Dead nettles (Lamium spp.)
  • Evergreen blackberry (Rubus laciniatus)
  • English holly (Ilex aquifolium)
  • English hawthorn (Crataegus monogyna)
  • English ivy (Hedera helix)
  • English laurel (Prunus laurocerasus)
  • European beachgrass (Ammophila arenaria
  • European mountain ash (Sorbus aucuparia)
  • Foxglove (Digitalis purpurea)
  • French broom (Genista monspessulanus)
  • Garden loosestrife (Lysinachia vulgaris)
  • Giant hogweed (Heracleum mantegazzianum)
  • Gorse (Ulex europaeus)
  • Himalayan blackberry (Rubus discolor)
  • Japanese knotweed (Polygonum cuspidatum)
  • Kudzu (Pueraria montana)
  • Mediterranean sage (Salvia aethiopis)
  • Pampas grass (Cortaderia selloana)
  • Purple loosestrife (Lythrum salicaria)
  • Reed canarygrass (Phalaris arundinacea)
  • Rugosa rose (Rosa rugosa)
  • Salt cedar (Tamarix ramosisima)
  • Scotch broom (Cytisus scoparius)
  • Spanish broom (Spartium junceum)
  • Sweet pea (Lathyrus latifolius)
  • Tree lupine (Lupinus arboreus)

For more information about Invasive Plants, visit:

References

  • Non-native pest plants of greatest concern in Oregon and Washington, as of August, 1997; PNW Exotic Pest Council, University of Washington, Seattle, Washington.
  • Understanding and Managing Invasive Plants in Wilderness and Other Natural Areas, 2002. Volume 4, Linking Wilderness Research and Management Series. USDA, Forest Service, Rocky Mt. Research Station. Report RMRS-GTE-79-Volume 4.
  • Grow Your Own Native Landscape, 1999. M. Leigh. Native Plant Salvage Project. WDU Cooperative Extension, Thurston Co.
  • Northwest Weeds, 1990. R. J. Taylor. Mountain Press Publishing Co., Missoula, Mt.
  • Illustration credits: Weeds of the Pacific Northwest, H. Gilkey. 1957. Oregon State University.