Pogostemon stellatus Octopus

Water parameters

Light and nutrients

Substrate type: rooted. Propagation: stem cutting.

Substrate compatibility

With fish

Origin and habitat

A stem plant of the mint family, Lamiaceae, Pogostemon stellatus (synonym Eusteralis stellata), also called water star or Austrian hygro, native broadly across tropical and subtropical Asia to northern Australia, including East and Southeast Asia, the Indian subcontinent and New Guinea, in marshes, rice paddies and slow waterways. The 'Octopus' or 'Broad Leaf' form is a long-leaved selection whose narrow, wavy leaves, 10–15 cm long and only a few millimetres wide, radiate in star-shaped whorls like tentacles, with pink to reddish-purple tops and purple undersides under strong light. It is a dramatic background plant for larger tanks. The standard form has shorter, broader leaves; 'Octopus' and 'Broad Leaf' are the longer-leaved trade selections. Most plants are sold as tissue culture.

Care notes

Moderate to demanding. It needs moderate to high light, around two to three watts per gallon or the LED equivalent, to keep the compact, colourful, whorled form; in low light the internodes stretch, the whorls space out and the octopus look is lost. CO2 is not strictly required, since it survives without, but it is effectively needed for dense growth and the pink-red tops, so most growers run it. Plant stems in groups of three to five, trim the tops and replant, though the cut lower stems branch less reliably than Hygrophila or Ludwigia. Iron and trace dosing supports the upper colour. Keep it around 22–28°C in soft to moderately hard water. The narrow flowing leaves contrast strikingly with broad-leaved plants and mosses, and it is a favourite competition background for the movement its whorls add. It is an ornamental, not a crop, so it is unsuited to media-bed aquaponics or hydroponics.

Further reading

• How to cycle a fish tank
• Water chemistry for fishkeepers: pH, GH, KH, and what they mean