Frogbit
Hydrocharis morsus-ranae · Hydrocharitaceae
The gardener's calendar
Ideal time to plant frogbit: set it out when the soil is neither frozen nor waterlogged, and water generously as it establishes.
ID card
- Scientific name
- Hydrocharis morsus-ranae
- Family
- Hydrocharitaceae
- Type
- Floating aquatic plant
- Flowering
- July to September
- Flowers
- Small white flowers with three petals
- Hardiness
- Down to -5 to -10 °C depending on region
- Growth
- Rapid in warm season
- Origin
- Europe, temperate Asia and North Africa
Care
Light and aquatic environment
Frogbit thrives in full sun or partial shade in calm, still or gently flowing water. It develops naturally in shallow lakes, ponds and marshes. Position it in a sheltered spot protected from wind that could damage its floating leaves.
Water management
This floating aquatic plant doesn't need watering in the traditional sense, as it lives completely submerged or at the water's surface. Maintain soft, clear water that is slightly still. In a pond, avoid jets or strong turbulence that would dislodge the floating rosettes.
Fertilizing and nutrients
Frogbit gets its nutrients directly from the pond or marsh water. An application of balanced aquatic fertilizer once or twice a month during active growth (spring-summer) can boost flowering. Avoid excessive doses that risk eutrophying the water.
Maintenance and control
Regularly remove dead or damaged leaves to keep the water clear and prevent rot. This plant quickly colonizes the water surface: thin out overcrowded rosettes in spring to control its spread and allow light to circulate.
Pests and common problems
Frogbit can suffer from rust or rot in overly stagnant water rich in organic matter. Regularly check the undersides of leaves to spot pests. Maintain good water circulation and remove decomposing debris.
Substrate and rooting
This floating plant doesn't need substrate. Its roots develop freely in the water or anchor lightly to the muddy bottom in shallow water. Ideally, use soft water with low lime content.
Did you know?
The scientific name Hydrocharis morsus-ranae literally means 'the bite of the water frog': ancient botanists believed this small floating plant was eaten by marsh frogs. In reality, the visible wear on the leaves comes from natural abrasion caused by water movement and aquatic insects, not frogs!
Where to buy it
Best planted in spring or autumn, away from frost and heatwaves. Pick a plant with healthy foliage and roots that are not exposed. Best time: March, April, May, September, October.
Add this plant to my garden →Plants from the same family
- Halophila decipiensHalophila decipiens
- Halophila spinulosaHalophila spinulosa
- Canadian waterweedElodea canadensis
- Halophila tricostataHalophila tricostata
- Halophila capricorniHalophila capricorni
- Nuttall's waterweedElodea nuttallii
Tips generated and checked by Viridia — adapt them to your local climate.