Invasive Weed Management

Integrated Pest Management

Noxious weeds are a well-established threat to Lakewood’s environment and cannot be
controlled by one method, alone. A toolbox of management techniques, known as Integrated Pest Management (IPM) has been developed to control the aggressive invaders. IPM consists of several control elements, including chemical, physical, biological and cultural. Each of these control methods works best under specific circumstances.

 

Chemical

  • Applying herbicides to all weed-infested areas where other methods would fail due to the immense size of these areas.

Physical

  • Pulling, mowing or any other physical weed removal.

Biological

  • Using organisms, primarily insects, to help remove weeds.

Cultural

  • Control using environmental factors, such as controlled burns and competition from native plants through revegetation.

Priorities and Goals

A list of priorities and goals has been established to gain control of noxious weeds in Lakewood. This plan provides the City with a specific course and will serve as a measuring stick to determine whether weeds are being eliminated.

  1. Currently, Lakewood is home to four noxious weeds considered by the Colorado Department of Agriculture as List A species. These include Myrtle Spurge, Cypress Spurge, orange hawkweed and Purple loosestrife.
    Goal – Achieve 90 percent control of all current species within five years.
    Goal Monitoring – GPS the outlines of each population, get the canopy cover every other year and compare the outlines to determine the percentage of control. Take pictures to get a visual record, a strategy that can be applied to all the goals.
  2. All other priorities revolve around List B and C weeds. Small populations of one weed species are a high priority. If the weed can be eradicated before an infestation begins, a serious problem may be avoided.
    Goal – Spray any small population with two days of finding the weeds and return the following year to ensure the population is eliminated.
    Goal Monitoring – Mark these populations on a map when they are found and return each year to check them. Repeat this until the weed population is gone, then return once more the following year.
  3. During the past five years, Lakewood has been working with the West Metro Fire Department to conduct prescribed burns on open space properties. These sites are the next priority. Fire helps clear old forage and stimulates native-grass growth. When these sites are sprayed, these weeds are more visible and susceptible to the herbicides. Weeds have declined significantly in areas where this practice has been used.
    Goal - Continue using controlled burns to control weeds.
    Goal Monitoring - Use ArcMap software to map and maintain records of each year's burn areas.
  4. Complaints. Much time is spent resolving issues before complaints arise, but when they surface, complaints need to be handled in a timely manner.
    Goal - Respond to any complaint within 48 hours. Follow up after three weeks and the following spring to ensure weeds are decreasing or eliminated.
    Goal Monitoring - Develop monitoring system to track dates complaints come in, when they are completed and dates of follow ups.
  5. Bear Creek Lake Park charges a fee for entry and, therefore, is considered a higher priority, which means more time is devoted to eliminating weeds in the park. The situation in the park is improving, which allows crews to focus their attention elsewhere.
    Goal - Control approximately 70 percent of the weeds from the 2008 mapwit in the next five years.
    Goal Monitoring - Complete a weed inventory of Bear Creek Lake Park every three years to determine the percentage of weeds controlled.
  6. Lakewood has a large spray trailer that can cover many acres one time. The next step is to use this trailer on a larger site, such as 50-acre plot of flatland just east of the Rooney parking lot at William Frederick Hayden Park.
    Goal - Use the spray trailer in large, flat areas until 90 percent of the weeds have been controlled. Then use more selective methods to the final 10 percent.
    Goal Monitoring - This can be accomplished by mapping the park every three years.
  7. Last on the priority list are sites filled with large numbers of trees, steep slopes and areas that are difficult to access. These sites must be treated with backpack sprayers and limited resources - a time-consuming process. Goal - Start treatment on the upper areas of Bear Creek in Bear Creek Lake Park, controlling all weeds with backpack sprayers for the first half-mile. Then treat the next half-mile stretch the next year, only after checking the previous year's area. Repeat the process each year until Bear Creek is finished, then start along Turkey Creek. Once Bear Creek Lake is completed, start the process along the Bear Creek Greenbelt. Goal Monitoring - Weed mapping.

Other considerations taken into account include wind direction, stream flow, trails and roadsides and weed concentrations. Wind primarily blows from the west; therefore, crews make efforts to spray from west to east sides of properties. To slow their spread, weeds are also controlled in an upstream-to-downstream pattern. Trails and roads indirectly spread weeds through recreation and vehicle use. Controlling these areas is crucial to minimizing spread. Areas with smaller concentrations of weeds are controlled to prevent low populations from rising.

Additional Goals

Educate the public about the importance of noxious weed control through volunteer events, brochures and programs.
Goal Monitoring - Maintain annual records about events and programs.

Weeds most successfully spread when they establish along trails and roads; control these areas to slow spread.
Goal Monitoring - Weed mapping, hiking along trails at taking notes at each year's spraying.

 

Contact Information:

Natural Resources Specialist
Direct: 303-697-3543 | Email: erinil@lakewood.org

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