Integrated Pest Management (IPM) uses a variety of treatments to manage noxious weeds.
Choosing a Treatment
The goal for controlling weeds is to create healthy, desirable plant communities that will be more resistant to weed invasion.
After identifying and mapping your weeds, you will be able to make decisions about which treatment methods you will be using. Consider using a combination of methods. Remember, if a weed is listed for eradication in your area, you will be limited to methods that are required by the CDA.
Using methods to stop the spread of weeds through equipment hygiene, weed-free seed and hay.
Pros - Stops weeds before they can grow, provides long-term benefits, provides cost savings.
Cons - Not always possible to get to all parts on equipment that has debris, may have to designate a cleaning site on the property.
Tips for success - Purchase weed-free hay, seed, and revegetation materials. Clean your equipment and gear before leaving a site.
Biological management uses organisms that disrupt the growth of the noxious weed. There are biological control agents (agents) available for some weeds but not all.
Different agents work differently but are specific to the targeted plants. Some feed on seeds, roots, foliage or stems as adults. Others feed as larva.
Biological control includes species of insects, pathogens, and livestock.
Some have previously been released and can be found in the area, others can be purchased through CDA and commercial suppliers.
Things to consider:
- Make sure your patch is a suitable size to support a population of agents.
- Not all the weeds you will be working on will have agents available.
- The agents may not work in your situation.
- It will take a number of years before the agents make a noticeable impact. You will need to continue to manage your weeds in the meantime using methods that are compatible.
- Biological control is not a method that can be used when eradication is required.
- If you are also using other treatment methods, make sure you understand their timing so you are not impacting the bio-control agents.
Visit CDA’s Insectary pages to find out more.
Pros - Organisms target specific plants, may be combined with other methods.
Cons - May not work at all sites, takes time to establish, may be costly, not allowed for eradication species.
Tips for success - Select organisms suited for your site, continue control efforts outside the release area, monitor to track the success of the organisms.
Cultural methods include using techniques to promote the growth and establishment of desirable vegetation.
Things to consider:
Will you be re-seeding or revegetating?
- Make sure you time your treatments to allow for optimum planting dates.
- If you are also using chemical, make sure you understand how long you need to wait before planting.
Pros - A healthy plant community can help resist invasion by noxious weeds.
Cons - Can be expensive. You will need to manage weeds as the newly seeded areas get established.
Tips for Success - Choose seed or plants suited for your site’s soil, moisture, slope and sun exposure. Plan on planting at the appropriate time for the types of plants you have chosen.
Mechanical methods involve disrupting plant growth. It includes methods such as tilling, mowing, burning, flooding, mulching, hand-pulling, hoeing, and grazing.
Things to consider:
Will you be pulling?
- Make sure the target weed is suitable for pulling.
- If the weed reproduces by seed, it is best to pull young plants before they bolt.
- For small patches, if the weed does not reproduce vegetatively, you can pull, dig or remove the vegetation and leave on the ground. But only plants with no buds or flowers on them.
- Make sure you get the top few inches of the root for weeds with taproots, and as much of the root mass for weeds with fibrous roots.
- Pulling is not effective for weeds with spreading root systems because they can reproduce from root fragments.
Will you be removing flowers?
- If the plant has new buds or flowers, cut and bag the flowers and dispose of in a landfill. For small patches, if the weed does not reproduce vegetatively, you can pull, dig or remove the vegetation and leave on the ground but only plants with no buds or flowers on them.
- If the plants have dead flowers from previous seasons, chances are they have already dropped their seed and your efforts to remove the dead flowers are not worthwhile unless you are doing so for aesthetic purposes.
Will you be cutting plants?
- If the weed can re-sprout, make sure the stump is treated using an additional method.
- If the plant can reproduce from fragments, make sure all pieces are bagged and disposed of at a landfill.
- Plan on revisiting the site to treat any regrowth.
Will you be mowing?
- Make sure you time your mowing so that the plants do not have buds or flowers.
- Plan on repeating monthly through the summer for perennial weeds.
- Collect and bag any pieces of weeds that reproduce from fragments and dispose of them in a landfill.
Will you be cutting hay?
- Make sure you are cutting before any weeds are flowering.
- If you are also using chemical, make sure you understand how long you need to wait to cut.
- Do not hay if you have weeds that reproduce vegetatively.
Will you be grazing?
- Not all weeds can or should be grazed. Make sure the weeds are safe for livestock.
- For weeds that can be grazed, learn the timing that will work for the type of animal you will be using.
- If you are also using chemical, make sure you understand how long you need to wait before you graze.
Pros - Works well for annual and biennial plants that reproduce by seed.
Con - May move seed and plant fragments, may disturb soil, may affect desirable plants.
Tips for success - Works well for weeds that reproduce by seed if done before plants have formed flowers or to early bolt stage. If flower buds have formed, then they need to be bagged and disposed of at a landfill.
Involves the application of herbicide or growth regulators to manage your noxious weeds.
Things to consider:
How will you be applying the herbicide?
- Make sure your equipment is calibrated. See CEPEP for information.
- Make sure you store any unused chemical, either mixed or concentrate, in a locked area away from children and pets.
- Read the label before applying. Only use on sites, with equipment, and use rates as listed on the label. The label also provides environmental, personal protective equipment, and other requirements.
Pros - Effective when used according to the label, can be economical, can be used selectively.
Cons - May affect non-target plants.
Tips for success - Use only as directed by the label including rates, sites, personal protective equipment, environmental conditions, and timing.
Selective vs Nonselective
Selective herbicides only kill certain plants or groups of plants. Non-selective herbicides kill all types of plants.
- Select the chemicals based on the following:
- What will work on the weeds you have?
- What is allowed for your site?
- What is allowed for how you use the land?
- If you have a number of different weeds, you will probably use more than one chemical. They may be able to be mixed and applied at the same time or may need to be applied separately. You will need to follow the label instructions.
- Choose chemicals and application techniques that will target the weeds and do the least harm to desirable plants.
- Do not use homemade herbicides or concoctions.
- Always read and follow the label.
Always follow the safety and environmental precautions listed on the label.
- Wear the personal protective equipment (PPE) required by the label. If no PPE is required, consider wearing rubber gloves, long sleeved shirt, long pants, and eye protection. Wash your PPE after each use.
- Do not apply if it is too windy. Some air movement is good but winds over 2-5 mph are too much.
- Do not apply when temperatures are too low or too high. Plants are not able to absorb chemicals at adverse temperatures.
- Adhere to label directions when applying near water. Avoid spraying adjacent to wellheads unless allowed by the label.
Storage and Cleaning
Always ensure that chemicals are out of the reach of children, pets and individuals not involved with the application.
- Only mix what you will use in one application.
- Consider buying a cabinet that you can lock to store your chemicals and equipment in. Keep out of the elements. Store between 40-70 degrees F. Some chemicals become inactive if they get too warm or freeze.
- Keep a copy of the label. You can find electronic versions online for many products.
- Triple rinse your empty containers by filling 1/3-1/2 full with water, agitate, pour reinstate into application equipment and spray onto a site allowed by the label. Repeat for a total of 3 times.
- Clean your equipment when you are done. Follow instructions on the chemical label. If the label does not have specific instructions, fill 1/3 full with water, agitate, and spray onto a site allowed by the label. Repeat for a total of 3 times.
- Clean your equipment if you are changing chemicals.
A Note on Pesticides
Pesticide is a general term that includes natural, biological, and synthetic compounds that kill, repel, or restrict the growth of organisms. The term pesticide includes insecticides, fungicides, herbicides, disinfectants, etc.
The label is the law. Pesticide labels describe how to use the chemical including items such as the allowed rates, sites, environmental and human precautions, equipment, and storage requirements. Failure to adhere to the labeled directions may result in damage to your site.
If you choose to use herbicides to manage your noxious weeds you need to read the entire label and make sure you are using it according to the directions.