Noxious Weeds and Management Strategies

1. Noxious Weeds and Management Strategies • Presented By: • Dale Whaley Washington State University Extension

2. Are all weeds bad all the time? • A weed in one place could be a benefit in another • Lots of weedy plants are used by birds, animals, insects and people • It depends on the threat to resources or ecosystems A honey bee visits bull thistle flowers F. & K. Starr, Starr Environmental, Bugwood.org

3. What is an invasive weed? • Introduced / non-native • Out-compete native plants • Change local ecology • Reproduce and spread rapidly D. Whaley, WSU Extension Diffuse knapweed Infestation

4. Invasive plants harm native habitats and species. Invasive plants like English Ivy transform forests and natural areas J.M. Swearingen, USDI National Park Service, Bugwood.org

5. Increased Risk of Fire D. Whaley, WSU Extension D. Powell, USDA Forest Service, Bugwood.org

6. Invasive plants impact wildlife. Humming bird stuck to Burdock burs eventually dying on the spot. D. Whaley, WSU Extension

7. Understanding Washington’s Noxious Weed Law and List

8. Washington’s noxious weed law involves both public and private landowners. King County NWCP King County NWCP

9. What is a noxious weed? • Non-native plant that impacts agriculture, wildlife, human health, land values or natural resources • Defined and regulated by state law (RCW 17.10) Visit the Washington State Noxious Weed Control Board website

10. Different lists regulate nurseries and landowners. • Noxious Weed List (WAC 16-750) • Weeds that are beginning to invade but not yet widespread • Regulated by county noxious weed boards • Property owner required to prevent plants from seeding • State Quarantine List (WAC 16-752) • To prevent spread of new introductions (does not include already naturalized plants) • Regulated by WSDA Nursery Inspection Program • Businesses are prohibited from selling plants or seeds

11. Noxious weeds are ranked by how widespread they are. • Class A Weeds – new invaders, control required statewide, still a chance to eradicate • Class B and C Regulated Weeds – control required only in particular counties or regions, still have a chance to stop them from getting established • Non-Regulated Class B and C Noxious Weeds and Weeds of Concern – control not required but definitely a good idea whenever possible

12. Here are a few examples of weed classes. Class C Non-Regulated: Old man’s beard Class B Regulated: Scotch broom Class A: Common Crupina J. Andreas, WSU Extension USDA APHIS PPQ Archive, Bugwood.org King County

13. Strategies for Managing Invasive Weeds S. Shaw, King County NWCP

14. Restore Weed Population Growth Control Prevent Ecology-based weed management is a long-term approach to weed management If less than 15% cover is desirable plants, then need to restore as well as control weeds Time

15. Get to know the type of weed in order to control it better. • Annual • Biennial • Perennial • Woody plant • Vine L.L. Berry, Bugwood.org S. Dewey, Utah State Univ., Bugwood.org Perennial: Spotted Knapweed Annual: Common Groundsel Utah State Univ. Archive, Bugwood.org King County NWCP Biennial: Tansy Ragwort Shrub: Scotch Broom

16. Getting to know your roots is especially important. K.W. Zobrist WSU Extension K.W. Zobrist WSU Extension K.W. Zobrist WSU Extension

17. Practice integrated pest management. • Prevention • Land management • Manual controls • Mechanical controls • Chemical controls • Biological controls

18. Prevention is the cheapest weed control method. D. Whaley, WSU Extension King County NWCP

19. Manual control is targeted and effective, but also lots of work. S. Shaw, King County NWCP C. Gray, GA EPPC, Bugwood.org Pulling and bagging garlic mustard Digging giant hogweed S. Shaw, King County NWCP Pulling gorse with a weed wrench

20. Make sure you have a disposal plan for the weeds you dig up. King County NWCP King County NWCP Make sure the weeds are dead when you leave them Noxious weeds that are regulated should go in the garbage. Commercial yard waste composting is good for widespread weeds

21. Mechanical control reduces the weed’s vigor without disturbing the soil. Be careful not to move weed seeds on equipment.

22. Sheet mulching is another way to starve the weeds without disturbing the soil. • Bark or woodchips over cardboard or layered newspaper - best for soil building • Geotextile fabric - good for weed control • Black plastic - cheapest, not good for soil T. Neuffer, WSU Extension King County NWCP

23. Biological Weed Control The intentional use of one living organism to control/suppress another organism, such as WEEDS Nematodes Caesar, USDA ARS; bugwood.org Insects Pathogens Mammals Piper, WSU; bugwood.org WSU Extension Healing Hooves

24. How Does It Work?

25. Solution – “Classical Biocontrol” 40-50 Degree Latitude Belt

26. Classic Noxious Weed Infestation Diffuse Knapweed

27. Solution – “Classical Biocontrol” 40-50 Degree Latitude Belt

28. Ideal Biocontrol Agent Characteristics • Host-specific • only attacks target weed • High searching capacity • capable of dispersing and finding host • High reproductive potential • produces many offspring • Long-lived adults • increase searching, egg distribution, compensates for asynchronies in phenology • Multi-voltinism • more than one generation a year

29. Advantages • Safe – USDA APHIS approves biological control agents before introduction into U.S. • Ecologically desirable – herbicide alternative • Insects are mobile • Long-term solution • Cost effective Leafy Spurge Biocontrol

30. Limitations Predatory mite Predatory insect • Long time to make impact • Subject to predators • May not establish at some sites • Very slow approval of new agents • No eradication

31. When To Use Biocontrol? • Established weed infestations • Remote, inaccessible, less disturbed areas • Areas not controlled by other means • Environmentally sensitive sites such as near water WSU Extension Kittitas CNWCB

32. When NOT To Use Biocontrol? • Small or new infestations • Highly disturbed areas • Roads or traveled paths • Areas unfavorable for insect • On weeds with no approved agents Mazerolle, Air Mazerolle, Air

33. Weeds with Biocontrol Agents • Scotch broom • tansy ragwort • meadow, diffuse, & spotted knapweed • Canada & bull thistle • purple loosestrife • St. Johnswort • yellow starthistle • puncturevine • rush skeletonweed • bindweed • Russian knapweed • Dalmatian & yellow toadflax • leafy spurge

34. Contact central Washington State’s biocontrol program for assistance and information. • Site assessments to determine if biocontrol is an option • Contact: • Dale Whaley, WSU Extension509-745-8531 officedwhaley@wsu.edu • Jennifer Andreas, WSU Extension 253-445-4657 office jandreas@wsu.edu

35. Chemical control can be highly effective but requires special care and knowledge. • Know your site • Know your weed • Know your product • Follow label instructions • Always be cautious and selective in your application King County NWCP

36. There are a few special considerations when using herbicides in forestry. Read the Forestry section in the PNW Weed Management Handbook: http://uspest.org/pnw/weeds

37. Here are a few useful websites for herbicide information. • WSDA Pesticide Licensing and Education • http://agr.wa.gov/PestFert/LicensingEd/default.htm • PNW Weed Management Handbook • http://pnwpest.org/pnw/weeds (see especially the chapters on Control of Problem Weeds) • Crop Data Management Systems, Inc. – labels and MSDS for most herbicides • http://www.cdms.net/manuf/manuf.asp

38. A Complete Integrated Vegetation Management Approach • Small Weed Infestations • Preventative measures such as; weed free mulches or utilizing certified weed-free seed • Control or Eradication of the population • Hand-pulling (physical control) • Mowing (mechanical control) • Spot spray (chemical control) • Once completed; utilize preventative measures in order to minimize future weed invasions

39. A Complete Integrated Vegetation Management Approach cont… • Large Established Weed Infestations • Large scale mowing or tillage operations to stop seed production (mechanical control) • not recommended for perennial type weeds • Herbicide applications to the weed perimeter (chemical control) • Incorporation of weed eating insects or goats/sheep (biological control) • Once completed; utilize preventative measures in order to minimize future weed invasions

40. Helping You Put Knowledge to Work! Dale Whaley Regional Extension Specialist 203 S. Rainier St., PO Box 550 Waterville, WA 98858-0550 509-745-8531 dwhaley@wsu.edu www.ncw.wsu.edu