The Southwest is known for its sunny climate and beautiful agriculture; however those same conditions which contribute to beautiful landscapes are also what promote unwanted plants or weeds as well. Today we are going to take a look at some of the most common weeds to this region as well as methods you can use to prevent their appearance or eliminate them from your property.
Crabgrass: A shallow rooted weed that thrives in poorly maintained lawns overrunning areas of the lawn which may be in poor health or dying. In the southwest, crabgrass seeds germinate in the spring and the use of a pre-emergence herbicide such as trifluralin can act to prevent crabgrass from taking hold. Elimination of active patches of crabgrass can be by many forms. With large amounts, simply pulling it up by the roots can resolve the problem but for sporadic lawn infestation a practice of deeply watering your lawn only once per week can serve to dry out the more shallow crabgrass roots allowing the hardier and deeper rooted grasses of your lawn to eliminate the crabgrass through competition.
Dandelion: Dandelions are common to nearly all areas of the United States and the southwest is no exception. Dandelions grow from deep taproots which make them hardy and drought resistant. If you attempt to remove these weeds by pulling them you must be certain to pull the entire root or else the plant will simply re-emerge in a matter of weeks. Special forked weed pulling tools are available that assist in this by sinking deep into the ground and allowing you to rotate the tool to wrap the root about the tines thus helping to insure complete removal. If you chose to use a chemical option for dandelion control then look for herbicides containing Dicamba or MCPP.
Russian Thistle: Russian Thistle (or tumbleweeds) are large plants which typically grow in areas of the southwest that are more arid or that have higher levels of winds and dust production. That is because the Russian Thistle requires these conditions in order to help spread it’s seeds. Prevention includes treating the area in late winter or early spring with a pre-emergent herbicide (Trifluralin) in order to prevent the weed from developing and to keep the area mowed as closely to the ground as possible until summer to prevent any weeds which do manage to sprout from being able to mature and produce seeds. For post-emergence elimination the use of herbicides which contain Dicamba or Triclopyr is advised.
For more information on identification of and treatments for these common weeds you may wish to go to:
New Mexico State University; Weed Identification site: http://weeds.nmsu.edu/
Southwest Biological Science Center: http://sbsc.wr.usgs.gov/research/projects/swepic/swepic.asp
