Many pollutants like trash, fertilizers, and oil wreak havoc on our water supply in the Truckee Meadows, but did you know that weeds also impact our water quality? That’s right – weeds. Weeds may not seem to be a very hot topic at the moment, however, they cause much more damage than you would think. Noxious weeds – as in weeds that have been identified by the state of Nevada to be harmful to agriculture, the general public, or the environment – can cause countless problems aside from damaging aesthetic value to communities. Other ways in which noxious weeds can impact our community include: 

  • Increased Soil Erosion 
    • Since invasive weeds are not adjusted to our soils and climate, their roots often cannot hold the soil and nutrients in place, therefore, causing soil erosion 
  • Increased Soil Salinity 
    • Soil salinity can be a result of shallow-rooted invasive weeds taking over deep-rooted native species such as trees, shrubs and pasture. When shallow rooted species take over, the water table will rise, thus bringing minerals and salts from the groundwater to the surface of the soil
  • Increased Flood Potential
    • Due to the fact that weeds are unable to hold nutrients and soil in place, the presence of invasive plants can affect waterways’ ability to hold water
  • Decreased Water Quality 
    • Weeds can impact water quality in a number of ways: erosion leads to increased sediment in our waterways, increased sediment leads to higher temperatures and thus lower oxygen levels, and the potential use of herbicides on weeds near riverbanks can drain into waterways and can cause algae blooms
  • Decreased Forage and Crop Yield
    • Weeds aggressively compete for water, nutrients and space therefore making it nearly impossible for crops to grow. Also, due to soil salinity, there can be detrimental effects on plant growth and yield
  • Displaced Wildlife and Native Plants
    • Nutrients can be hard to come by, especially when you’re competing with an invasive weed. Weeds will out-compete other plants for nutrients, sunlight, and space, leaving native flora in the dust. While the native plants are suffering, so are the local animals. The native fauna had adapted to co-exist with certain plant species, and when those plants are out-competed by weeds, the animals have lost their source of food and shelter. 
  • Reduced Recreation Potential 
    • The presence of weeds affects the aesthetic value of properties as well as the health of native species. Higher levels of sedimentation in our waterways, increased risk of erosion and flash floods as well as fewer sightings of native flora and fauna will lead to lack of opportunity for recreational activities 
  • Increased Fire Danger 
    • Once weeds have gone dry they become an extreme fire hazard. Invasive species such as Cheatgrass and Medusahead are quite common as well as flammable.

In an attempt to stop weeds in their tracks and to pay for damages caused by weeds, the United States pays up to $137 billion every year. 

What Noxious Weeds Should I Keep an Eye Out For? 

These 5 weeds are very common and very harmful to our community here in Washoe County

  1. Musk Thistle
  2. Yellow Starthistle
  3. Puncture Vine 
  4. Perennial Pepperweed
  5. Medusahead

Musk Thistle – “Nodding Thistle”


  • 2 – 6 ft. tall 
  • Flower is rather large at about 3 in. wide. 
  • Flowers are pinkish or purple (sometimes can be white, as well)
  • Be careful during removal, stems and leaves are spiny 

Yellow Starthistle


  • Can range from 1 to 6 ft. in height
  • Famous for their yellow flowers found at the tip of the stems with spines branching out just below the flower. Spines can grow from 0.5 – 1 in. long

Puncturevine – “Goatheads”


  • Low growing, grow in a mat-like form 
  • Have very small, yellow flowers (0.2 – 0.6 in. in diameter); flowers have 5 petals
  • Produce woody burs (a dry fruit with hooks or teeth) that often break into 5 sections. These are also known as “goatheads” – known for poking holes in tires and sticking to shoes. Foliage can be toxic to livestock. 

Perennial Pepperweed – “Tall Whitetop”


  • Up to 6 ft. tall 
  • Small, white flowers with 4 petals, arranged in clusters at the tip of the stems
  • Grows best in moist places, such as near waterways, floodplains, etc. 



  • Stems can be .5 – 2 ft. long
  • Seedhead is a spike, 0.5 – 2 in. long. Bristles are stiff and can be straight or twisted. Bristles can be up to 3 in. long

Spread the Word, Not the Weed 

Other than eradication, there are many other ways that you can help slow the spread of invasive weeds. Some easy steps you can take and practice everyday are: 

  • Come Clean: Before leaving home, take time to inspect and remove dirt, plants, and bugs from clothing, boots, gear, pets, and vehicles. 
  • Leave Clean: Before leaving the trail, campsite, etc, inspect your belongings and remove any dirt, plants or bugs. Also check your pets paws and fur! 
  • Stay on designated trails: Stay on the designated trail when walking, hiking, running, biking, or riding your horse or OHV.
  • Be informed: Learn about invasive species that are a problem in your area. Learn about and use native plants that grow well in your area. Visit for more information!




This program is supported by funding from the Nevada Division of Forestry, Dept. of Conservation and Natural Resources through a Landscape Scale Restoration Grant awarded by the US Forest Service.