Height: surface floater
Water depth: any
Soil: neutral or acid
Site: full sun
Type: floating perennial
Rosettes of small, bronze-green, kidney-shaped fleshyand tiny white flowers, composed of three petals and a yellow centre, make frogbit (Hydrocharis morsus-ranae) a favourite floating aquatic. The flowers appear in late summer, 2.5-5cm (1-2in) above the water surface. It is particularly good for a small pool or wooden barrel filled with water.
Frogbit dies down in autumn and overwinters as submerged dormant buds at the bottom of the pool, reappearing again mid spring.
In areas with harsh winters, overwinter a few dormant buds in a jar filled with soil and water, kept in a cool but frost-tree place.
Place the plants on the water in spring in full sun. Frogbit will thrive in pools above acid or neutral soil, but not unlined pools in lime-rich soil. Any water depth is suitable. Control the spread by pulling unwanted plants out with your hands.
Propagation: Increase by dividing colonies in spring and summer.
Pests and diseases: Trouble free.