Alien plants may be invasive or non-invasive. The whole issue of alien plants is important because of those that are invasive. An invasive plant is one that "takes over" an area or ecosystem.

Discussion of Alien Plants

• Perennials
• Shrubs
• Trees
• Grasses
• Vines
• Aquatic plants

Roads Open Up Paths for Weed Invasions - Environment News Service, Apr 18, 2003

Common Burdock - a Kinglet Killer - Jean Iron (Please note that there is some disagreement as to which species of burdock are native or alien)

Alien Invaders Along the Grand - Larry Lamb

Garlic Mustard:

• Garlic Mustard: The Invader’s Edge - The Monday Garden, December 29, 2002, issue no. 40, by Sue Sweeney

• Photographs of Garlic Mustard
  Learn to identify this plant, and see examples of how it takes over an area of woods or even a field.

• Why is Garlic Mustard so invasive?

• Thesis by Peter Moc: "The effect of alien plant species on native plant richness and community composition in urban mid-age Sugar Maple (Acer saccharum) dominated forests in London, Ontario" by Peter Moc, 4th Year Honours Thesis, Department of Plant Sciences, University of Western Ontario, April 2001

Asiatic Bittersweet - The Monday Garden, December 29, 2002, issue no. 40, by Sue Sweeney

Porcelainberry - The Monday Garden, October 27, 2002, issue no. 31, by Sue Sweeney

Porcelainberry: Disaster in the Alley - The Monday Garden, August 29, 2004, issue no. 127, by Sue Sweeney

Tree Ivy Secrets - The Monday Garden, February 9, 2003, issue no. 46, by Sue Sweeney

Wolf Moon: Rose Hips - The Monday Garden, January 26, 2003, issue no. 44, by Sue Sweeney

Invaders' Salad: Chicory - The Monday Garden, July 13, 2003, issue no. 68, by Sue Sweeney

Meadow Killer: Spotted Knapweed - The Monday Garden, September 14, 2003, issue no. 77, by Sue Sweeney

Ailanthus: Tree of Heaven and Brooklyn - The Monday Garden, November 16, 2003, issue no. 86, by Sue Sweeney

Shades of Maple: Death by Norway - The Monday Garden, November 23 2003, issue no. 88, by Sue Sweeney

Loosestrife - The Monday Garden, October 26, 2003, issue no. 83, by Sue Sweeney

Invaders: Asiatic Bittersweet - The Monday Garden, August 22, 2004, issue no. 126, by Sue Sweeney

Invaders: Barberry and Winged Euonymus - The Monday Garden, May 16, 2004, issue no. 112, by Sue Sweeney

Invaders: Japanese Knotweed - The Monday Garden, May 2, 2004, issue no. 110, by Sue Sweeney

Lesser Celandine: Marsh Menace - April 10, 2005, issue no. 159

Invasive Plants: Killing and Controlling (Them, Not Us) - April 17, 2005, issue no. 160