Eradicating Invasive Obedient Plant Without Harming Neighbors

Obedient plant (Physostegia virginiana) spreads aggressively via rhizomes. Removing it from a mixed bed with coneflowers, hibiscus, lilies, and clematis requires precision.

Three Approaches (Labor-Intensive but Effective)

1. Dig and Treat (Most Thorough)

1. Dig up desired plants (carefully—coneflowers have taproots).
2. Apply horticultural vinegar (20% acetic acid) to remaining obedient plant foliage.
3. Or spot-treat with glyphosate (paint on leaves).
4. Wait required interval; replant saved perennials.

2. Persistent Hand-Pulling

• Remove every shoot as it appears.
• Trace rhizomes laterally.
• May take 2+ seasons.

3. Spot-Treatment In Situ

• Use foam brush to apply herbicide/vinegar only to obedient plant leaves.
• Shield neighbors with cardboard.
• Repeat as needed.

Critical Precautions

• Horticultural vinegar burns skin/eyes—wear protection.
• Glyphosate kills any green tissue contacted.
• Don't compost invasive roots.

Complete eradication takes persistence, but your valuable perennials can be saved.