Floating pond plant
Frogbit
Hydrocharis morsus-ranae
A free-floating native UK pond plant forming rosettes on the surface with white flowers; grow in still, alkaline water and manage coverage to keep about half the surface open.
PLANT PROFILE
About Frogbit
Frogbit (Hydrocharis morsus‑ranae) is a free‑floating perennial that forms leathery, rounded to heart‑shaped leaf rosettes which rest on the water surface, with small white three‑petalled flowers borne above the water. RHS cultivation notes and conservation sources show it is suited to sheltered, still or slow waterbodies with calcareous conditions and is commonly used in garden ponds when introduced and managed correctly.
Because frogbit is free‑floating it is introduced to the water surface rather than planted to a specific depth. It overwinters by producing dormant buds or turions that sink beneath the surface (or to the bottom) and then renew growth in spring, so a pond should be deep enough to protect these overwintering structures from bottom freezing. Propagation methods supported by RHS guidance include sowing seed, division of stolons or runners, and collecting and potting plantlets or turions.
Freshwater Habitats Trust and Plantlife note that frogbit is a native, locally uncommon species with conservation value (listed as Vulnerable in GB Red Data summaries), so only local, native, wild‑sourced stock should be added to garden ponds and wild populations treated as conservation features. RHS pond guidance recommends keeping roughly 50% of the surface clear and thinning floating plants if they begin to overcrowd. Quarantine new purchases and avoid releasing unwanted material into the wild; treat maintenance cuttings as bio‑waste and dispose of them responsibly. The plant is hardy (RHS H5) and the RHS lists it among popular floating pond plants, with straightforward cultivation advice: full sun, still alkaline water, and protection of overwintering buds.
POND SUITABILITY