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Invasive Plant Facts - A Biological Nightmare

Weeds attached to truck
Weeds in tire tread
Seeds attached to shoes
Seeds attached to shoes

For most people, weeds are just a minor nuisance in their gardens and lawns. However, exotic or invasive weeds are more than a minor problem. Already infesting 70 million acres in the United States, invasive weeds continue to expand their range by 4,600 acres a day - on public lands alone!

What makes these exotic invaders so aggressive? Possessing unique physical adaptations for survival, combined with the absence of their natural enemies, invasive weeds easily establish large populations - giving them a distinct competitive edge over native plants. The resulting monocultures have a devastating economic an ecological impact. Native vegetation is altered (affecting forage for livestock and wildlife); crop, land, and recreational value decrease; and entire ecosystems are damaged.

Goats used to combat weed problems

To combat this silent invasion, government agencies and private landowners have developed cooperative efforts to combat invasive weeds, utilizing a variety of control measures. Unfortunately, control measures alone will not win the war on weeds. Preventing the spread of invasive weeds is an overwhelming task that depends on each of us. To be an active "weed warrior", we all should become familiar with these biological nightmares.

Unique Adaptations

To compete with other plants in their native habitat, invasive weeds have developed unique biological adaptations.

  • Extremely efficient at converting the sun's energy into explosive plant growth
  • Many invasive weeds can establish new plants from seeds AND roots
  • Seeds can remain viable for over 50 years
  • Extensive root system with large food reserves
  • Production of biological toxins and the ability to change soil chemistry - prevents establishment of other plants
  • Seeds have various adaptations to spread easily
  • Plants can tolerate severe environmental condition

On the Move

  • Invasive weeds spread at an alarming rate. Naturally, the seeds may spread by water and wind, or by attaching to wildlife, livestock, horses, or people.
  • Weeds seeds are not selective when it comes to hitch hiking on a vehicle - motorcycles to construction equipment work equally well
  • Boaters, fishermen, hikers, or hunters can inadvertently spread weeds by picking up seeds on their clothing, equipment, and pets!
  • Agricultural products, especially hay, is an ideal transport media for weed seeds
  • Unaware of the potential problem, commercial seed companies and nurseries sell invasive weeds as ornamental plant.