---
tags:
  - Green & Commercial
  - Weed Science
  - Marble
---

# Weed Control in Ornamentals for the Nursery and Landscape
## GTBOP Green & Commercial — 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
**CEU Categories:** Category 10 (Private), 21 (Plant Ag), 23 (Forestry), 24 (Ornamental/Turf), 27 (Right-of-Way), 31 (Public Health), 32 (Regulatory), 35 (Industrial/Institutional/Structural/Health)

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## Deliverables

| Stage | Deliverable | Status |
|-------|-------------|--------|
| 1 | [Corrections Log](corrections.md) | Complete |
| 2 | [Archive Summary](archive-summary.md) | Complete |
| 3 | [YouTube Version](platforms/youtube.md) | Complete |
| 3 | [Website Version](platforms/website.md) | Complete |
| 3 | [Extension Agent Version](platforms/ext-agent.md) | Complete |
| 4 | [Quiz](activities/quiz.md) | Complete |
| 4 | [Matching Exercises](activities/matching.md) | Complete |
| 4 | [Review Prompts](activities/review-prompts.md) | Complete |
| 5 | [Prose Transcript](prose-transcript.md) | Complete |
| — | [Processing Log](processing-log.md) | Complete |

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## Session Overview

Dr. Chris Marble presented a comprehensive guide to developing herbicide programs for nursery and landscape ornamentals, addressing both production and landscape settings. He identified poor calibration as the number one reason herbicides fail, highlighted free UF-developed calibration calculators, and walked through a three-step process for selecting herbicides: determine what is labeled and safe for the target ornamental, identify target weed species, and build a year-round rotation using different modes of action.

The core demonstration used container-grown gardenia as an example, building seasonal rotations targeting spotted spurge and eclipta in warm months and bittercress, annual bluegrass, and oxalis in cool months. Marble presented research showing that combining pre-emergent and post-emergence treatments reduced total herbicide use by 40–60% and costs by up to 30%. He also reviewed post-emergence alternatives to glyphosate and highlighted underutilized selective options for grass, sedge, and broadleaf management in ornamental beds.

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*Source: Corrected SRT — GTBOP_Transcript_2023-07-13_WeedControlOrnamentals.srt (618 blocks)*
*Processed: 2026-02-27 | Pipeline v4.1*
