The goal of the Columbia Shuswap Regional District Noxious Weed Control Program is to prevent the spread of those weeds which may have a serious, detrimental effect on agricultural practices in the Regional District. Once weeds infest an area and produce seeds, they become increasingly difficult and costly to control.

Until 1989, the Columbia Shuswap Regional District had operated a herbicide control program for roadside infestations. This approach to noxious weed control was inefficient and was not cost effective as only those weeds adjacent to roadways were controlled. The implementation of inspection and enforcement programs increases overall control program effectiveness. By placing the obligation to control noxious weeds on the landowner or occupant of land, the weed inspector can concentrate on reducing the spread of noxious weeds through increased surveying, identification and notification to control.

Weed control methods can be divided into five categories: prevention, physical, cultural, chemical and biological. A well-planned weed control program will often combine two or more of these methods.

Physical Control

Physical control may include total removal, covering of growing plants, exposing roots or stressing weeds to prevent seed production. Tillage is the most common method of physical weed control. Burial of growing plants is only partly effective on weeds with underground stems and roots that are capable of sprouting. Deep tillage is used to dislodge or cut the root system so the plant dies from drying out or from frost damage. Repeated tillage is usually required to effectively control perennial weeds.

Mowing and pulling (hand robing) can be an effective way to control annual weeds if done often enough to prevent flowering and seeding. Some perennial weeds can be killed by mowing where several cuttings cause the plants to expend food reserves contained in their roots.

Cultural Control

In cultural control, plant competition or cropping practices are used to suppress weeds.  It is important to:

• Establish a vigorous, dense growth of cultivated plants to reduce competition with weeds.
• Prevent over-grazing and ensure that bare areas or unplanted fields are regularly tilled or planted with annual or perennial species which are quick to germinate and have rapid early growth to compete with weed species.
• Rotate crops to help reduce the build-up of high populations of certain weeds common to a particular crop.

Chemical Control

Herbicides can be used to prevent seed production, remove leaves, kill entire plants or greatly slow their rate of growth. Conditions of temperature, humidity and rainfall influence the effectiveness of herbicides. Correct timing of applications, herbicide choice and usage of the appropriate application rates and equipment will provide the desired level of control.

For assistance in choosing the appropriate chemical control agent and application method contact your local weed inspector through the Columbia Shuswap Regional District or the District Agriculturalist at the Ministry of Agriculture, Food and Fisheries.

Biological Control

Biological control as it relates to weed control is currently accomplished through the use of insects, competitive plantings or disease-causing organisms such as fungi, viruses or bacteria. Most problem weeds have been introduced from elsewhere - mainly Europe and Asia and as such, rapidly increase in the absence of their natural enemies. Biological control usually involves the importing and introduction of these natural enemies to areas where weeds have become established.

Biological control is a slow process and does not provide immediate control since it typically takes from 3 to 10 years for the controlling organism to become established and reduce the local weed population to a manageable level. Currently, there are several biological control programs in effect in the Columbia Shuswap Regional District area and other areas of the province.

For more information on noxious weeds, the Columbia Shuswap Regional District Noxious Weed Control Program or to report a noxious weed infestation, please contact the