You have probably come across weeds in your lifetime, whether it was making wishes on dandelions as a child or pulling pesky crabgrass from your beautiful lawn. Weeds are plants, just like the grass in your yard which means they flourish in the same conditions as your lawn. While weeds can be discouraging, there are solutions to control weeds without damaging the grass or surrounding plants.
Table of Contents
The weeds that are shown below don’t represent the full spectrum. For more comprehensive list, please see the PDF below.
What Is A Noxious Weed?
Noxious weeds are non-native invasive plants that, if left uncontrolled, can dominate existing native and formal plantings. These weeds can be aggressive and spread quickly. The term ‘noxious weeds’ includes non-native, invasive grasses, shrubs and trees, flowering plants and aquatic plants. The Colorado Department of Agriculture (CDA) created the Colorado Noxious Weed Act which was developed to create and enforce regulations intended to control these weeds.
There are three separate lists, A, B, and C which categorize weeds by importance for control. Group A is the highest priority. It is vital to educate and teach others about these weeds to ensure our open spaces are protected from these aggressive plants that threaten the balance in our ecosystems.
List A:
Rare noxious weeds that must be removed statewide.
List B:
Discretely distributed noxious weeds that must be eradicated, contained, or suppressed, depending on their location, to stop their continued spread.
Canada Thistle
Common Teasel/Cutleaf Teasel
List C:
Widespread and well-established noxious weeds in Colorado; control is recommended by the state and may be required by local government.
Common Mullein
Field Bindweed
Perennial Sowthistle
How Do Noxious Weeds Spread?
Species of noxious weeds tend to spread and grow in prime locations such as construction sites that have been cleared for building, roadsides, overused areas by humans and animals, and wetlands. The soil can also be disrupted through naturally occurring events such as wildfires, mudslides, avalanches and floods. These weeds are mainly scattered by wind, animals, water, and humans and can produce more than 10,000 seeds per year. Their roots can also grow up to 30 feet long.
How To Prevent Noxious Weeds
Prevention of these invasive weeds is a high priority and ensures that noxious weeds are not introduced into un-infested locations. A few ways to help prevent the spread of these weeds is by identifying and eradicating small infestations, monitoring and evaluating to avoid new growth, and revegetating and reclaiming disturbed sites with the appropriate native plant species.
Educating landowners on the Promotion of the Colorado Weed-Free Hay and Forage Program and restricting the unlawful sale of invasive plants and seeds are other great ways to prevent noxious weeds.
How To Control Noxious Weeds
There are quite a few ways to control established noxious weeds. The Integrated Weed Management (IWM) incorporates ways to manage and provide prevention tips on how to control and remove them. According to the IWM, these treatment options break down into four categories.
Cultural
Establishing healthy native or other vegetation which consists of proper grazing management (prevention of overgrazing), re-vegetating or re-seeding, fertilizing and irrigation.
Biological
The use of an organism such as insects, diseases and grazing animals to control noxious weeds; useful for large, heavily infested areas. Not an effective method when eradication is the objective, but it can be used to reduce the impact and dominance of noxious weeds.
Mechanical
Manual or mechanical means to remove, kill, injure, or alter growing conditions of unwanted plants. Methods include mowing, hand-pulling, tilling, mulching, cutting and clipping seed heads.
Chemical
The use of herbicides to suppress or kill noxious weeds by disrupting biochemical processes unique to plants.
Native plants are healthy for the ecosystems and provide genetic material that helps strengthen major food crops, enhance landscapes and even provide shelter and food to animals. By controlling the noxious weeds in the area, the native plants will have a better chance at surviving and returning the following year.
With increased awareness and education about the effects of noxious weeds, we can help maintain our ecosystem. Landowners should contact local agencies if they have questions or concerns about these invasive species or help identifying which plants need to be removed.
If you need assistance with the healthcare of your plants or landscape, contact us today and our PHC experts will assist you.
