Floating Pennywort

The Problem?

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Photograph by Dan van den Toorn

Introduced in the 1980’s as a garden pond plant, Floating Pennywort (Hydrocotyle ranunculoides) now forms dense mats on still or slow moving waters. Floating Pennywort out competes native plant species whilst also reducing light, lowering temperature and deoxygenating the water.

What We Are Doing?

Floating Pennywort is found on out Coatham Marsh reserve and can be seen choking the Fleet. Previously we have used mechanical control to remove the plant whilst this year under an agreement from the Environment Agency we used contractors to spray the plant with Round Up Pro Biactive. Floating Pennywort can regrow from small fragments and as a result our efforts to eradicate it from our reserve has so far been unsuccessful.