Noxious Weed Information

Life Cycle of Weeds

• Annuals
  - Complete their life cycle in a growing season
  - Spread by seed
• Biennials
  - Complete their life cycle in two growing seasons
  - Reproduce by seed (rosette form first year, flower and seed production during second year of life cycle)
• Perennials
  - Live three or more years
  - Reproduce by seed, underground root structures, and/or plant cuttings

Noxious Weeds Listed for Becker County

• 18 State Prohibited Noxious Weeds
  Prohibited noxious weeds must be eradicated or controlled as required in Minnesota statutes (more information)
  Eradicate List: 
  1. Yellow Starthistle Centaurea solstitialis L.
  2. Grecian Foxglove Digitalis lanata Ehrh
  3. Oriental Bittersweet Celastrus orbiculatus Thunb.
  4. Japanese Hops Humulus japonicas Siebold & Zucc.
  5. Dalmation Toadflax Linaria dalmatica (L.) Mill.
  6. Common Teasel Dispsacus fullonum L.
  7. Cut-leaved Teasel Dispsacus laciniatus L.
  8. Giant Hogweed Heracleum mantegazzianum
  Control List:
  1. Leafy Spurge Euphorbia esula (L.)
  2. Canada Thistle Cirsium arvense (L.) Scop.
  3. Musk Thistle Carduus nutans (L.)
  4. Plumeless Thistle Carduus acanthoides (L.)
  5. Garlic Mustard Alliaria petiolata (M. Bieb.) Cavara & Grande
  6. Purple Loosestrife Lythrum salicaria (L.)
  7. Wild Parsnip Pastinaca sativa L.
  8. Common Tansy Tanacetum vulgare L.
  9. Spotted Knapweed Centaurea stoebe L. ssp. Micranthos(Gugler) Hayek
  10. Narrowleaf Bittercress Cardamine impatiens L.
• 3 State Restricted Noxious Weeds
  Restricted noxious weeds are prohibited from importation, sale, and transportation in the state except as provided by Minnesota Statutes (more information)
  1. Common/European Buckthorn Rhamnus cathartica (L.)
  2. Glossy Buckthorn (& all cultivars) Frangula alnus Mill.
  3. Multiflora Rose Rosa multiflora Thunb.
• 1 State Specially Regulated Plant (more information)
  
  1. Poison Ivy Toxicodendron radicans (L.) Kuntze
• 1 State Non-Regulated Species of Concern
  
  1. Wild Carrot Daucus carota
• 3 County Prohibited Noxious Weeds (more information)
  * Proposed for 2011:
  
  1. Absinthe Wormwood Artemesia absinthium
  2. Hoary Alyssum Berteroa incana
  3. Houndstongue Cynoglossom officinale L.

Basic Concepts of Weed Management to Consider

1. Be persistent; think long-term - No quick fix for weed problems
2. Manage small infestations immediately - Small weed populations can be managed quickly and efficiently.
3. Contain large weed infestations - Large weed populations take many years to manage, avoid the spread of existing infestations.
4. Education of the public is important - Inform landowners on key weed problems and how to identify important weeds.
5. Use an IPM approach when possible - Integrated Pest Management techniques used together, have shown greater results than using one weed management technique alone.

Common Management Practices

• Pre-emergent Herbicides - Used in early spring mostly in agricultural crops
• Spring and Fall Tillage - Successfully controls many weeds in agricultural fields
• Spring and Fall Burning - Enhances the growth and development of desirable plants for increased plant competition in natural areas and rights-of-ways
• Biological Control - Works well on large established stands of leafy spurge, purple loosestrife, spotted knapweed, and garlic mustard
• Contact Herbicides - Most effective when used to treat emerging seedlings, rosettes, and perennial plants in the early spring and fall
• Pre-seed mowing - Reduces flower and seed production of many weed species; can also be a major factor of weed seed spread if performed after seed development
• Woody Perennial Treatment - Cutting and/or pulling of woody species like buckthorns can be effective if cuttings are followed with stump treatments and spot-spraying of emerging seedlings

Windows of Opportunity for Weed Management Practices
(Click on graphic for full size view)