GTBOP Webinar Archive — Extension Agent Resource

Weed Control in Ornamentals for the Nursery and Landscape


Webinar Information

Field Details
Date July 13, 2023
Speaker Dr. Chris Marble, Associate Professor, Ornamental and Landscape Invasive Weed Management, Mid-Florida Research and Education Center, University of Florida
Moderator Dr. Shimat Joseph, UGA Turfgrass Entomologist
Duration 50:38
Series Green & Commercial

Applicable CEU Categories

Category Description
10 Private Applicator
21 Plant Agriculture
23 Forestry
24 Ornamental and Turf Pest Control
27 Right-of-Way Pest Control
31 Public Health Pest Control
32 Regulatory Pest Control
35 Industrial, Institutional, Structural and Health Related

Asynchronous Viewing Instructions

This archived webinar is approved for continuing education credit in the categories listed above. For asynchronous CEU delivery, participants should view the complete 50:38 recording and complete any associated assessment activities. The video chapter list below can be used to navigate to specific content segments for review.


Content Summary

Dr. Chris Marble presents a comprehensive guide to developing weed management programs in nursery production and landscape ornamentals. The presentation covers calibration and application fundamentals, pre-emergent and post-emergence herbicide timing, a systematic three-step process for herbicide selection and rotation by mode of action, and research demonstrating the cost and environmental benefits of combining pre-emergent and post-emergence programs. Marble also reviews alternatives to glyphosate for non-selective post-emergence control and highlights underutilized selective herbicides including graminicides, Basagran, Lontrel, and Certainty. A brief Q&A covers signal words, drift reduction, and Marengo use in nursery non-crop areas.

Key Topics for CEU Relevance

This session is particularly relevant for professionals managing weed control in ornamental nursery production, commercial landscape maintenance, and right-of-way applications. Topics include herbicide mode of action rotation, the 2017 Southeast Pest Control Guide as a decision tool, label compliance and calibration, research on reducing total herbicide use through integrated pre/post programs, signal word classifications and PPE requirements, and drift reduction strategies. The presentation's emphasis on developing site-specific programs rather than relying on single products supports best management practices across all applicable license categories.


Video Chapters

0:00 Introduction and Speaker Credentials 0:58 Overview: Weed Control in Nurseries and Landscapes 1:36 Why Herbicides Fail: Calibration and Application 4:34 Calibration Tools and Mixing Calculators 6:35 Pre-emergent Herbicide Timing 8:20 Avoiding Plant Injury During Application 9:29 SureGuard Holly Trial: New Growth vs. Hardened Foliage 10:42 Post-emergence Herbicide Timing 11:30 Environmental Factors Affecting Efficacy 13:18 Stressed Weeds and Mowing Impacts 14:28 Ranking Factors That Impact Post-emergence Performance 15:38 Importance of Developing a Program, Not Just Products 17:17 Herbicide Rotation and Resistance Prevention 18:48 Three Steps to Choosing Herbicides 19:17 Pre-emergence Options Color-Coded by Mode of Action 20:48 The 2017 Southeast Pest Control Guide 21:00 Step 1 Example: Labeled Options for Container-Grown Gardenia 22:02 Grouping Herbicides by Mode of Action 23:01 Step 2: Targeting Primary and Secondary Weed Species 25:20 Step 3: Building a Year-Round Rotation 27:03 Year-Round Nursery Rotation Plan by Month 27:34 Research: Pre-emergent + Post-emergent vs. Post-Only Programs 30:44 Cost Savings and Herbicide Reduction Results 31:55 Application Interval Considerations 32:09 Landscape-Specific Rotation Planning 33:52 Timing Examples: One, Two, or Three Applications Per Year 35:20 Generic Landscape Rotation Example by Season 37:01 Post-emergence Alternatives to Glyphosate in Landscape Beds 38:08 Glufosinate (Finale/Cheetah) as an Alternative 38:43 Non-Selective Alternatives: Desiccant-Type Herbicides 40:12 Acetic Acid Trial: Burndown and Recovery Results 42:23 Selective Post-emergence Options for Landscape Beds 43:04 Graminicides: Underutilized Grass-Selective Herbicides 43:55 Basagran, Lontrel, Certainty, and Scepter 44:44 UF Mid-Florida REC Resources and Contact Information 45:52 Q&A: Signal Words and PPE Requirements 48:02 Q&A: Wind Drift and Reducing Spray Drift 49:08 Q&A: Marengo for Nursery Gravel Areas


Additional Resources

  • 2017 Southeast Pest Control Guide for Nursery Crops and Landscape Plantings — Free download or ~$20 hard copy from NC State. Contains herbicide efficacy and ornamental safety charts referenced throughout the presentation.
  • UF Mid-Florida Research and Education Center — Dr. Marble's faculty page with free calibration calculators, weed ID resources, and publications.

Part of the Getting the Best of Pests (GTBOP) Green & Commercial Webinar Series UGA Center for Urban Agriculture / GTBOP Archives