For recommendations on chemical control, please review the information provided in the references below. Additional advice may be obtained by contacting the Washington County Master Gardeners at 503-821-1150. You can also Ask an Expert at OSU Extension at http://extension.oregonstate.edu/mg/metro/ask-an-expert.
Integrated Pest Management
Anyone – farmers, homeowners, or natural areas managers – can use multiple strategies for controlling weeds.
Integrated pest management is an ecosystem-based strategy that focuses on long-term prevention of pests or their damage through a combination of techniques such as biological control, habitat manipulation, modification of cultural practices, and use of resistant varieties.
Basically, it means using all of the tools in your toolbox to battle weeds. These include:
Biological control is the use of natural enemies—predators, parasites, pathogens, and competitors—to control pests and their damage. Invertebrates, plant pathogens, nematodes, weeds, and vertebrates have many natural enemies.
Cultural controls are practices that reduce pest establishment, reproduction, dispersal, and survival. For example, changing irrigation practices can reduce pest problems, since too much water can increase root disease and weeds.
Mechanical and physical controls
Mechanical and physical controls kill a pest directly or make the environment unsuitable for it. Traps for rodents are examples of mechanical control. Physical controls include mulches for weed management, steam sterilization of the soil for disease management, or barriers such as screens to keep birds or insects out.
Chemical control is the use of pesticides. In IPM, pesticides are used only when needed and in combination with other approaches for more effective, long-term control. Also, pesticides are selected and applied in a way that minimizes their possible harm to people and the environment. With IPM you’ll use the most selective pesticide that will do the job and be the safest for other organisms and for air, soil, and water quality; use pesticides in bait stations rather than sprays; or spot-spray a few weeds instead of an entire area.
–From UC Davis.
Learn more about IPM: www.ipm.ucdavis.edu/GENERAL/whatisipm.html
Weed ID and Control Fact Sheets
Provided by Tualatin Watershed Weed Watchers
Learn the basics about identifying and controlling invasive and noxious weeds here in Washington County.
For more weed ID and control articles, visit Tualatin SWCD’s Weed of the Month archive:
See also: GardenSmart
The GardenSmart booklet has information about the many choices of plants that work for gardens while protecting watershed health. GardenSmart also highlights plants you should avoid because they are invasive, and has information about non-invasive alternatives (both natives and non-native ornamentals) that you can safely plant instead. Please use this booklet as a guide to help you make informed choices for your garden, water garden or landscape.
Weed Watchers are trained deputies in the fight against invasive species in Washington County. Each year, we host workshops with hands-on learning about the weeds we want you to help us detect early and respond to rapidly by reporting them.
Find workshops dates and learn more at www.swcd.net/workshops-education/weed-watchers/
The goal of this program is to teach citizens to look for (Early Detection) and report (Rapid Response) new, high priority invasive plant species before they spread.
- View the “Weed Watchers EDRR ID Guide” to help you identify these high priority species:
Weed Watchers EDRR Intro Guide | Forbs | Grasses | Shrubs | Vines | Closing
- Attend a Tualatin Basin Weed Watchers Workshop to learn how to identify these species. Visit our calendar for upcoming workshops.
How to Report:
You can report your sightings online at oregoninvasiveshotline.org/
Step 1: Collect information about your sighting
If you suspect that you have found any of the weeds included in the EDRR guide above, please record the following information so that we can follow up on your report.
1. Take a picture of the plant: Include something to show scale (a ruler or common object like a coin) and close-ups of distinctive features of the plant. Take your time to make sure the photo is in focus.
2. Collect a written description of the plant: Flower color, shape and size; leaf shape and size; is the plant hairy, etc.
3. Collect location information: GPS coordinates are the best, but written directions to the site work too. The closest address, intersection or mile marker, or how far past a trial or bridge crossing, as well as nearby landmarks are most helpful.
4. What size is the infestation? How many feet wide and long is the patch? How many plants do you estimate are there?
Step 2: Report your EDRR sighting
There are two ways to report the sighting:
Online: Visit www.oregoninvasiveshotline.org and click ‘Report Now’.
Phone: Call us at 503-648-3174, then dial extension 5 to leave a message with the details of your report. You may email photos collected to email@example.com