# GTBOP Webinar Archive — Extension Agent Resource
## Weed Control in Ornamentals for the Nursery and Landscape

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### 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.

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### 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.

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### 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

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### 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.

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