Banana plant
Nymphoides aquatica
Also known asBanana lily · Big floatingheart · Banana floatingheart
Water parameters
Light and nutrients
Substrate type: inert ok. Propagation: plantlets on stems.
Substrate compatibility
| Substrate | pH effect | Nutrient load |
|---|---|---|
| Inert sand (Pool filter sand) | neutral / inert | none |
| Inert gravel (Aquarium gravel) | neutral / inert | none |
| Aquasoil (ADA Amazonia) | lowers pH | very high |
| Mineralized clay substrate (Seachem Fluorite) | neutral / inert | moderate |
With fish
Origin and habitat
Native to the southeastern United States, from Texas east to Maryland and concentrated in Florida, in calm ponds, slow rivers and lake margins; Maryland lists it as endangered. It is an aquatic member of the family Menyanthaceae and gets its name from the cluster of thick, green, banana-shaped storage roots at its base, which hold nutrients and anchor the plant. From these the plant raises round, lily-pad-like floating leaves on long petioles, up to about 10 cm across, and bears small white flowers above the surface, while submersed leaves are smaller, short-stemmed and heart-shaped with a notch at the base. In the trade it is usually sold as a novelty for its odd 'banana' tubers.
Outdoor pond use
- USDA zones
- 8–11 (winter low around -12°C or warmer)
Care notes
Set the banana tubers on the substrate or press them in no more than a third of the way; bury them deeper and they rot. True roots grow from the base to anchor the plant. Under low to moderate light it keeps its submersed, heart-shaped leaves, but under strong light or in shallow water it sends long petioles to the surface, opening floating lily pads and eventually flowering, so most aquarists trim the floating leaves at the petiole to keep it compact and stop it shading the tank. It is a genuine low-tech plant: CO2 is not needed, and the tuber's stored energy means a freshly planted one often grows well for the first month before slowing as reserves run down, after which moderate light and a little iron-bearing fertiliser keep it healthy. Propagate by the daughter plantlets that form on the leaves: let a leaf float until it grows roots and small leaves, then plant the young plant. It tolerates a broad range, pH 6 to 7.5, soft to moderately hard water and about 20°C to 28°C, and is reasonably cold-hardy. Catfish and snails may nibble the tubers but rarely do real harm. It is an ornamental novelty, not a crop, so it is unsuited to media-bed aquaponics or hydroponics.