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Tall Whitetop

Tall Whitetop

Tall Whitetop is devastating to the environment

The tufts of small white flowers are one of nature's sneaky deceptions. Tall whitetop may look like a delicate, harmless flower, but in fact this alien weed has already invaded thousands of acres of Nevada's lands and waterways. It threatens water quality, wildlife habitat, recreational activities and the economic stability of some of our ranchers. If it's not contained now, this invasive species will cause major environmental damage and economic losses (see "Fast Facts" below).

Nevada Legislature endorses Tall Whitetop Initiative

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Tall whitetop poses such a threat to the state that the 1999 Nevada State Legislature asked University of Nevada Cooperative Extension to head up a two-year Tall Whitetop Initiative. Its goal is to teach Nevadans how to recognize, control and eradicate this noxious weed.

Tall whitetop usually blooms in May and June

Tall whitetop stands 2 to 7 feet tall when in full bloom, with clusters of fluffy white flowers. It spreads by underground roots which grow 10 feet or more, sending up shoots to form new plants. It also spreads by its tiny reddish seeds. Each plant produces as many as 10,000 seeds that invade and destroy new areas, making the weed extremely difficult to control. Tall whitetop prefers wet sites along rivers and ditches. It invades sensitive stream areas and chokes out native plants that help prevent stream bank erosion and that are important to Nevada's wildlife.

Tall whitetop is a problem for every Nevadan

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Tall whitetop is especially troublesome to Nevada's ranchers and farmers. Their livelihood is threatened by the invasion of noxious weeds that decrease the quality of hay, forage and other crops. The invaders are particularly devastating after wildfires, such as those experienced in Nevada in 1999.

However, tall whitetop is not just a rural problem. It, and other invasive weeds, have been spotted in nearly every Nevada county. The aliens can and do live in urban areas, flourishing in irrigated yards and producing seeds that can be transported to other areas. During construction, heavy equipment moves dirt and the thousands of seeds it contains to infest new areas. This is one tough, resourceful weed!

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We need to pull together!

Help us protect our environment, economy and water quality by joining the war on weeds! The key to controlling tall whitetop and other invasive weeds is to catch them when they're a $10 problem, not a $10,000 problem. Be on the lookout! If you spot tall whitetop, dig it out and watch it carefully. If the infestation is large, call your local Cooperative Extension office (see phone numbers on the back page). Your call will help us map infestations so that control measures can be started and evaluated. It will likely take several years, so let's begin the battle now!

Invasive Weed Fast Facts

  • Tall whitetop has invaded thousands of acres of Nevada's lands, including about 20,000 acres along the Truckee River.
  • Noxious weeds have infested 17 million acres of public rangelands in the West.
  • The economic impact of invasive weeds on the U.S. economy is estimated at $123 billion a year.