American water-willow (Dianthera americana) care guide

Group

Plants

Other names

American water-willow, Water-willow, Justicia americana

Family

Acanthaceae (acanthus family)

Origin

Eastern North America, from Quebec and Ontario south to Georgia and Texas and west to Nebraska and northern Mexico

Water

freshwater

Maximum size

100 cm

Temperature

4–26°C

pH

6–8

Care level

expert

Lighting

Bright light; grows emersed

Flow

Prefers flowing water

Care

American water-willow is a plant of shores, streambanks and shallow riverbeds, best known by its older name Justicia americana. It strongly prefers flowing water and grows in gravel, sand or mud, with willow-like leaves on erect stems usually 50–100 cm tall (up to about 1.5 m in deep water). It is an emergent marginal plant rather than a true underwater plant, so it is best used at the edge of a pond or stream, or with its leaves above the water in a paludarium. Our sources say nothing about aquarium use. It is a temperate plant that suits tropical tanks poorly. Water figures are our estimate, not from the sources. Sources: Wikipedia (en.wikipedia.org/wiki/Justiciaamericana); Wikipedia, List of freshwater aquarium plant species. Checked October 2026.

Breeding

Very easy from stem cuttings. In the wild it spreads by creeping rhizomes and runners that root at the nodes, forming colonies of 90 m² or more, and floating fragments re-root.

Compatibility and tank mates

Best in coldwater ponds and streams. Fish rarely damage the emersed stems.

Last updated 8 October 2026. Community-edited care guide on Aquatic-Auctions.