Weed Prevention

  Weeds, it seems like they're everywhere.  In your yard you see a weed start to take sprout, in your fields, on the sides of your driveway, and when you're on vacation.  Why are all the weeds there and how do you make them disappear?  It's one of those things that you just wish you could snap your fingers and the weeds would go away but it's not that easy.  What do you do then to make them go away?  Well, I hope you learn some techniques about how to stop weed infestations from this paper about weed prevention.  I am going to tell you: 1) what are weeds, 2) how to keep track of the weeds you have, 3) how to prevent weed intrusion, 4) how to detect and stop new weeds from introducing themselves into an area, 5) how to start competitive grasses and, 6) how to manage the grasses and area you removed weeds from.  (Sheley, 2005)
    What are weeds?  A weed, according to the Columbia Encyclopedia, is a “wild plant” and an “undesired plant” it seems as though it grows exactly where you don't want it to grow on cultivated ground.  When a weed isn't grown on cultivated ground and is in its natural habitat the weeds usually serves a purpose.  When, although, the weed is on cultivated land they compete with your crop.  The weeds will take the nutrients, water, and sunlight that your crops need to survive and therefore becomes a problem.  The weeds can also attract many pests and different insects that may harm the crops that are grown in that area.  Weeds also add beauty, serve as a source of food, help soil become softer, help prevent erosion from happening, and enrich the earth.  So, there are pros and cons to having weeds in different areas, (but mostly cons)!  (The Columbia Encyclopedia, 2006)

    My next question that I am going to answer is how does a person keep track of the weeds that they have and why does that person even need to keep track of something like that?  To be able to keep track of the weeds that you have on your land you usually will need some assistance.  You can get that assistance by getting someone to conduct a field survey, by getting information from geographic information systems, or by aerial photography.  Then you can have some one identify the weeds through a private party or by getting a hold of the local Extension Noxious Weed Specialist.  Then after you have gone through that process you will need to map this information very accurately.  You need to do all of this: seeing, recording, and mapping because when you come up with a prevention plan you need to know where the weeds are and if they are decreasing in numbers or increasing.  You will see if your efforts to prevent the weeds are helping or not.  That is why you need to keep track of the weeds on your property.  (Sheley, 2005) and (New Mex
icoStrategic Plan for Managing Noxious Weeds, 2005)

                         Figure 1 Sheley, Roger et. al., 1/22/05

    Now I am going to tell you how to prevent weed invasion.  Weed prevention is the best method for preventing and keeping noxious weeds under control.  Weeds are spreading at incredible rates and we need to step up now and take control of them.  Figure 1 shows where knapweed was fist, in the 1920’s, and how the population of it grew so much that by 1982 knapweed had invaded every county in Montana.  We can stop the weeds by doing many different easy things such as limiting weed
seed scattering, not letting nearby weed infested areas spread to an area without weeds and, having very little soil disturbances.  Those are the methods that will eliminate a lot of our weed intrusion.  Now I am going to tell you how to effectively put these methods into use so you can prevent weed intrusion. (Sheley, 2005)
    The first method I mentioned on how to prevent weeds was to limit weed seed scattering.  Weed seed scatters many different ways.  One way weed seed is dispersed is through machinery.  The vehicle or machinery gets the weed seed stuck to it (often carried by the undercarriage), and then gets blown out in a new area and starts a new infestation.  You're probably thinking to yourself, ‘what can I do about my vehicle picking up weed seeds, I can't prevent that from happening?’.  Well, to your surprise you can do something to limit the amount of weed seeds your vehicle picks up.   To be able to limit the amount of weed seed you spread, try not to drive through the weeds when the weed is in the seeding period.  Also, wash the undercarriage of your vehicle with a high powered car wash if you happen to go through an infested area.
(Sheley, 2005)  (J. J. Mullahey, 2005)
    Weed seed is also spread by animals.  For example, a cow spreads weed seed two different ways: 1) by eating the seeds and having the weeds spread in a different area through their feces, and 2) they also carry the seeds in their hair and drop them in other places which cause a new infestation.  People can help solve this problem by not having that animal in an area with weeds that are blooming or seeding. This will solve the problem of the weeds being eaten and spread through feces or being carried by the animal's hair.  Weed seed is spread also by animal's feed. The feed problem can be solved by having your feed certified weed free or ground so there is no or very little weed seed in the feed.
  (Sheley, 2005)  (J. J. Mullahey, 2005)
    Weed seed is also spread by recreational activities.  The weed seed being spread by recreational activities such as hiking and camping can be stopped by brushing off your clothing and camping equipment at or near the sight and burning the weed seeds. (J. J. Mullahey, 2005)  (Sheley, 2005)
The next point I mentioned on how to prevent weed invasion was to not let nearby weed infested areas spread to an area without weeds.  You can do this by using an herbicide.  If you use an herbicide to contain nearby infestations you need to know a lot about the weed you are trying to contain.  If you spray the weed too early or too late it won't do anything to the weed.  You also need to plan on spraying the weeds for a long time because the herbicide isn't designed to kill the weeds only contain them.  The herbicide can also be very dangerous if not used correctly so you need to realize how to apply the herbicide, and how much of the herbicide you need.  That is how you can contain weeds so they don't spread and make new infestations.  (“
The War on Weeds”. This Old House, 2006)  (J. J. Mullahey, 2005)  (Sheley, 2005)
    Invasion of weeds can be prevented by having very little soil disturbances.  Soil disturbances are caused by many different things such as livestock, machinery (vehicles), and wildlife.  When something disturbs the soil by over grazing, or driving where it is not aloud this causes a disturbance in the soil and erosion.  The noxious weeds can then more easily grow in the soil disturbances than native plants because of the weeds characteristics.  So, after one seed starts, pretty soon there is an invasion and hundreds of weeds are in that area.  To stop this whole process from happening people really need to think about what they are doing before they do it.  For example, if something isn't an emergency you should never have to disturb the ground by ‘making your own road’ or when the livestock/animals have grazed down a certain area to a good healthy length than you should take them out of that area and put them in another.  Common sense things like that will prevent noxious weeds from even ever starting.  That is how you can effectively prevent weed invasions by changing some of the things you do every day. (J. J. Mullahey, 2005)
Now I am going to tell you how to detect and stop new weeds from introducing themselves into a specific area before they become a real problem.  You do this first by using the map that you made of the area with the noxious weeds marked.  You need to know the boundaries of the weeds you're trying to eliminate and narrow the area down into smaller regions so you can take care of them more efficiently.  Then, you need to decide the procedure that best fits the weed you are trying to get rid off.  The options you might want to consider are having animals graze it, using an herbicide, pulling the weeds by hand, or using bio-control insects to get rid of the weeds.  Some of the procedures I just mentioned will take a while to get rid of the weeds and will take a lot of time and effort, but it will all pay off in the long run when you have a productive and healthy field.  After you have used one of those procedures to get rid of the weed you will still need to check the area around 3 times a year or more to make sure none of the noxious weeds have reseeded and are starting a small infestation that will lead to a big one.  That is how you can prevent weeds from becoming a bigger problem than they have to be by stopping their growth early.  
(J. J. Mullahey, 2005)  (“The War on Weeds”. This Old House, 2006)  (Sheley, 2005)
Now I am going to tell you how you can start competitive grasses/forbs so they out compete any thing else that might invade the area.  This method is one of the best long term methods for never having weeds imbed in that area again.  You may need to do one of the two things that I am going to mention.  You can either use a chemical to control the weeds and to let the desirable grass take over or you may need to totally start over by the means of revegetation.  You can have insects come into that area and decrease the number of weeds so the grass can reestablish itself again.  The way you can use revegetation is you can use an herbicide in the fall (or spring after the noxious weeds have just come up) and the shortly after plow up the area.  After you have plowed up the area that you have used the herbicide on, Roger Sheley tends to think that drill seeding is the most effective method to use to reestablish the ground.  When you have the right grass/forbes in the right places then you won’t have a problem with the weeds that you don’t want there because there will not be (hopefully) any bare spots for the weeds to start sprout.  That is how you can start the competitive grasses that you want.   (J. J. Mullahey, 2005)  (Sheley, 2005)
Lastly I am going to tell you how to manage the plant community and the area that you removed the noxious weeds from.  This involves a lot of monitoring to know what exactly is happening.  You need to be able to ‘revive’ the grass every two to four years by burning the grass, cutting the grass, and/or grazing that area.  Livestock should be an important role in managing and keeping control of the area, but they need to be monitored to make sure the land isn't being abused by grazing or by litter accumulation.  The grasses on your land needs a lot of time to revive again so the livestock that you have on that specific area need to be moved somewhere else for healthy growing and prevention of weeds.  All of this should limit the noxious weeds and keep your grasses healthy.  That is what you need to do to be able to manage and take care of the land you removed the noxious weeds from.  (J. J. Mullahey, 2005)  (Sheley, 2005)
In this paper about weed prevention I told you: 1) what weeds are, 2) how to keep track of the weeds you have, 3) how to prevent weed intrusion, 4) how to detect and stop new weeds from introducing themselves into an area, 5) how to start competitive grasses, and 6) how to manage the grasses/forbes and area.  That is all that I talked about in this paper.  My opinion on this subject is that weeds need to be prevented even if you need to spend large an amount of time on preventing them.  I think that the best way to prevent weeds is to make a map of the area and eliminate the weeds by either an herbicide or insects.  Then, my opinion is after you get rid of the weeds you need to establish some very competitive grasses/forbes.  That keeps the noxious weeds from reestablishing.  That is what my opinion is on how to prevent weeds.  I hope you will consider these things which I have said and try to prevent weeds yourself.  I hope that the methods and the ways I explained them are helpful in some way to you.


Sheley, Roger et. al., Preventing Noxious Weed Invasion. Aug. 2002., MSU Extension Service., 21st Dec. 2005, <http://www.montana.edu/wwwpb/pubs/mt9517.html>.

Sheley, Roger., Noxious Weed Management., 31st July 2001., Montana State Weed Science., 21st Dec. 2005, <http://weeds.montana.edu/range/management.htm>.

Mullahey, J. J. and Brecke, B. J., Pasture weed Management., Aug. 2002., IFAS Extension. 22nd Dec. 2005, <http://edis.ifas.ufl.edu/BODY_AG174>.

The Columbia Encyclopedia., Columbia: High Beam Research, 2005.

New Mexico Strategic Plan for Managing Noxious Weeds., 2000-2001., New Mexico Strategic Plan for Managing Noxious Weeds., 22nd Dec. 2005, <http://www.swstrategy.org/library/NM%20Strategic%20Plan%20for%20Managing%20weeds.htm>. 

Ocone, Lynn., “The War on Weeds”., This Old House, 8th July 2004: 5pg.

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by: Tressa Gnerer
February 2006