Methods of Weed Control

Any combination of these methods would constitute an Integrated Management Program.

Preventive Control

Preventive control is self explanatory. It literally means to keep the weed or weeds from invading your land. Do this by inspecting your land for any unwanted or noxious weeds. Any plant that looks as if it should not be were it is may be a potential weed. Once a weed is found, eradicate it immediately. Do not let the weed have a chance to reproduce. There are several books with colorful pictures of weeds that can be used for identifying plants. Or you can call the Larimer County Weed Control District, Colorado State University, or the Larimer County Extension Service for help identifying unknown plants you find on your property. The Larimer County Agronomist in charge of the Weed District will come out to your land and help you do a site analyze and help you develop a management plan.

Chemical Control

Herbicides used properly by following the label and with common sense, is one of the main methods of control. Herbicides have several different modes of action. Before purchasing any herbicide, read the label to ensure that particular herbicide will do what you intend it to do. There are herbicides that will only effect broadleaf plants. Some will only effect grasses. These type herbicides are called selective. Examples are 2,4-D, Banvel, Tordon, Poast and many more. Some herbicides are non-selective, that is they will effect all vegetation or most of it. Examples are Roundup, Arsenal, Spike and more. Some herbicides should not be used after the temperature raises a certain degree. All this is found on the label. Remember the label is a legal document and if not followed, can be the cause of litigation.

Seek assistance before purchasing or using a herbicide if you are not absolutely sure of the use or purpose of the product.

Biological Control

Biological control is the use of living agents as a method of control. These agents can be; insects, bacteria, fungii, or animals such as sheep, goats, cattle or horses. Some of these agents are very successful, while others are not so good. Most of these agents are limited to certain site criteria before they are effective. Inspect your land or site to make sure that the criteria is met before using any of these agents. Of course, the grazing animals do not have the limitations as the insects or other agents. Insects are expensive to purchase. Do not be misled by some who say insects are the cure-all for weed control. This is not true. Even with the successful insect control, it still takes years to see the results. In the mean time, the weeds are still reproducing. There has to be another control in place to keep the infestation in check until the insects can become established. Check with the local agencies such as CSU, the Extension Service, or the Weed District for more information before you spend your money.

Mechanical Control

Mechanical control is the use of machinery, or any form of manual exertion (work) to control weeds. This includes the use of mowers, plows, chopping, etc. Mechanical control is very sensitive to timing to be effective. When you mow, plow or chop needs to be done at the plants correct stage of growth. Most mechanical controls need to be done several times during the growing season. All of this information can be obtained through the Weed Control District, CSU or the Extension Service.

Cultural Control

Cultural control is probably the most sensible control method available to the agricultural community. It simply means to change something to make it harder for the weeds to grow or become established. Grazing, crop rotation, reseeding, fertilization, are all cultural practices that can enhance weed control.