Controlling Unwanted Plants from Industrial to Ornamental Settings

1. Controlling Unwanted Plants from Industrial to Ornamental Settings 25th Annual Region Two Herbicide Training Seminar

2. Weed Control In Ornamentals

3. There is a Weed for All Places and All Seasons

4. Terminology • The technical terms of a particular trade science or art.

5. Terminology An Overview • Life Cycle • Annuals • Biennials • Perennials • Taxonomy • Grasses • Sedges • Broadleaf Plants

6. Classification of Weeds • Life Cycle: A method of grouping plants based on length of time from germination to seed production • Taxonomy: The discipline of assigning names to organisms based on shared characteristics

7. Life Cycle The length of time for a plant to grow, flower, and set seed.

8. Life Cycle • Annual • A true annual is a plant that completes its life cycle in one year. This means it goes from seed to seed and then dies off, during the course of one growing season.

9. Life Cycle • Annuals • Winter Annuals: germinate in the fall or winter, live through the winter and bloom in the winter or spring. Catchweed bedstraw Field Pennycress

10. Life Cycle • Annuals • Winter Annuals: germinate in the fall or winter, live through the winter and bloom in the winter or spring. • Summer Annuals: germinate, flower, and produce seed in the warm months of the year. These plants generally die with the onset of cold weather. Common mallow Crabgrass

11. Life Cycle • Biennials • Plants that take two years to complete their biological life cycle Wild Carrot Onion

12. Life Cycle • Perennials: Plants that live more than 2 years. • Herbaceous: plants that have little to no woody growth • Woody: Plants that produce woody stems (Trees and Shrubs) Common Chicory Shrub Honeysuckle in the Foreground

13. Taxonomy(grouping by shared characteristics) • Grasses • Sedges • Broadleaf plants

14. Taxonomy (grouping by shared characteristics)Grasses • Herbaceous plants with narrow leaves growing from the base. • Growing point is at the base of the leaves • Include cereals, bamboo, turf grasses, meadow grasses

15. Taxonomy (grouping by shared characteristics)Sedges • Stems with triangular cross-sections • Leaves spirally arranged in 3 ranks • Often associated with wetlands or poor soils

16. Taxonomy (grouping by shared characteristics)Broadleaf Plants • Growing point is at the tip of the shoot or side branch • Typically called Dicots – flowering plants with two embryonic leaves or cotyledons

17. Weed Control Program • Having a weed control program puts you on the offense!

18. Weed Control Program3 Parts • 1. Clean up weeds (especially perennial weeds) on the site prior to planting. • Why? • Wider variety of herbicides available prior to installing plant material • Cultivation and soil preparation can be performed without concern about “damaging desirable plants”

19. Weed Control Program3 Parts • 1. Clean up weeds on the site prior to planting. • 2. Prevent weed growth in and around the area. • Premergence herbicides • Mulch

20. Weed Control Program3 Parts • 1. Clean up weeds on the site prior to planting. • 2. Prevent weed growth in and around the area. • 3. Eliminate “missed” weeds as they appear. • No method provides total control • Don’t allow missed weeds to establish or set seed

21. Considerations for Developing A Weed Control Program • Four Things to Think About as you Design Your Weed Control Program

22. Considerations for Developing A Weed Control Program • One application of preemergence herbicide at label rates will not provide season long weed control Do Not Expect Season Long Control From One Application

23. Considerations for Developing A Weed Control Program • One application of preemergence herbicide at label rates will not provide season long weed control • No single preemergence herbicide controls all weeds Grasses and broadleaf weeds often require different chemistry

24. Considerations for Developing A Weed Control Program • One application of preemergence herbicide at label rates will not provide season long weed control • No single preemergence herbicide controls all weeds • If one type of weed is controlled and another is not – the uncontrolled weed type will take over the area

25. Considerations for Developing A Weed Control Program • One application of preemergence herbicide at label rates will not provide season long weed control • No single preemergence herbicide controls all weeds • If one type of weed is controlled and another is not – the uncontrolled weed type will take over the area • Once you invest time in cleaning up a weed problem – do something to prevent weed regrowth Make your investment count

26. Weed Control Methods • Physical • Chemical

27. Physical Weed Control • Cultivating • Mowing • Mulching • Hand pulling • Selecting a weed free growing medium • Planting cover crops

28. Chemical Weed Control • Preemergence • Postemergence • Contact or translocated • Selective or Non-selective

29. Chemical Weed Control An Introduction to Some Common Herbicides

30. Glyphosate • Post emergence, non-selective • Absorbed through green tissue – leaves, stems or whatever is green • Translocated throughout the plant • Best results on perennials occur when fall applied – translocation downward • Uses • Pre plant -- site cleanup and preparation • post plant -- directed spray around established plants

31. Snapshot • Granular • Preemergence material • Mix of Gallery and Treflan • Effective on grasses and broadleafs • Apply under mulch • Landscape, field and container grown ornamentals • Some bulbs and groundcovers • Label allows the user to experiment on small groups of plants

32. Surflan • Preemergence • Aqueous solution – applies as a liquid • Primarily controls grasses • Apply over or under much • Established landscape, field, and container grown ornamentals • Some bulbs and groundcovers

33. Industrial Weed Control Photo: Mike Maurer

34. Considerations • Site Factors • Vegetation • Timing • Herbicides

35. Site Factors • Surface Texture • Slope • Water Movement • Margins

36. Surface Texture

37. Slope (and Water Movement)

38. Margins root spread

39. Margins

40. Or… • Keeping herbicides where you put them

42. Considerations • Site Factors • Vegetation • Timing • Herbicides

43. Problem: continual weed germination and encroaching perennials.

44. Annual vs Perennial > Root system

45. Targets: kochia, annual grasses • Kochiascoparia • Summer annual • Thrives in harsh environments • Foxtails, barnyardgrass, sprangletop, goosegrass… • Late season germination

46. Kochia

47. Annual grasses Photo: Mike Maurer

48. Vegetation Well established vegetation Postemergence herbicides needed Site vegetation-free Preemergence herbicides

49. Considerations • Site Factors • Vegetation • Timing • Herbicides

50. Goal = season-long control • Application timing • Herbicide rates • Breakdown of herbicides > half-life • Persistence