Pogostemon stellatus

Pogostemon stellatus, commonly called Broadleaf Rotala in the aquarium hobby (though unrelated to Rotala), is a large and impressive whorled stem plant native to tropical Asia and Australia. Its comparatively wide, star-shaped whorls of narrow-to-medium leaves develop beautiful pink to purple-violet tones under high light in soft, slightly acidic water, creating a visual spectacle that rivals specialist Rotalas.

It is more demanding than P. erectus, requiring high light, CO2, soft water, and iron-rich fertilisation for good colouration. In hard water or without CO2 the plant tends to grow slowly and loses its pink-purple pigmentation, remaining a dull greenish. Temperature should be kept at 24–28°C for tropical forms.

Best used in large background groups in advanced high-tech setups. Its broad whorls create a distinctive layered texture different from the needle-whorled P. erectus, adding variety to Pogostemon groupings in Dutch and Nature Aquarium layouts.

Light: High (60–100 PAR); pink-purple tones require strong, consistent illumination. CO2: Required at 25–35 mg/L; colouration and compact growth both depend on CO2. Fertilisation: Iron and micro dosing 2–3× weekly; adequate macros maintain growth rate. Placement: Background; groups of 5–7 stems with 3–4 cm spacing. Propagation: Trim tops at 12–15 cm and replant; side shoots develop within 10–14 days.