Pogostemon helferi

By: Ole Pedersen

Pogostemon helferi is a different but beautiful foreground plant which under good growth conditions forms a dense carpet of dark green leaves. The curly leaves and different leaf form make it stand out from the crowd of other foreground plants and thereby, it creates an attractive variation and regeneration of the planted aquarium.

The full scientific name is Pogostemon helferi (Hook. f.) Press and from this it follows that it is closely related to another popular aquarium plant, Pogostemon stellatus. The meaning of the genus name is "bearded stamens" from "pogo" (bearded) and "stemon" (stamen) but as yet there is no English common name for Pogostemon helferi. Two Thai aquarist, Nonn Panitvong and Arthit Prasartkul, recovered the plant on the boarder between Thailand and Myanmar and in Thailand the plant is called "dao noi" which means little star. Here, the plant is found in between the other amphibious vegetation along creeks and small rivers where it is found submerged during the wet season and emerged during the dry. The soil in this part of Thailand is often iron rich clay with a reasonable amount of calcium carbonate and this makes it ideal as an aquarium plant.

Pogostemon helferi is not easily confused with other aquarium plants because of the curly leaves. Under good light conditions, short internodes are formed which result in a compact and bushy look. The inflorescence is simple, 15-30 mm long and the individual flowers are lavender. Usually, it forms flowers only when emerged.
At Tropica, we cultivate Pogostemon helferi in emergent cultures which bring along advantages not only for Tropica but also for the aquarist. The emergent plants are always free from algae but in addition, they also acclimate much easier to the water in the individual tanks found among different aquarists. The reason is likely that in nature, these plants experience large natural fluctuations in water quality upon the start of the wet season when ions in different amounts are washed out from the catchment area. This phenomenon probably makes the plant more adaptive to submergence in different types of waters also in our tanks. When planting Pogostemon helferi into the aquarium, the cluster of plantlets should be divided into 4-5 blocks which are then planted into the substrate with a distance of 3-5 cm. In this way, a homogenous carpet is rapidly formed. Remember to remove loose leaves or leaves which are already senescent together with big lumps of roots. This tissue will soon die anyway and start to decay, and this will slow down the establishment of the new plants.Pogostemon helferi looks best if it is planted in small groups or even in larger groups in the foreground.

Pogostemon helferi is not particularly light demanding, but the more light we provide, the more compact the growth form, and the compact form is what most people find attractive. Under less light, the plant grows taller (up to 15 cm) whereas intense light results in compact shoots not longer than 5-8 cm. Pogostemon helferi is relatively fast growing and thus, it needs additional nutrients. Iron deficiency sometimes occurs and is recognized by the new leaves being yellowish but this is easily treated by using liquid Premium Fertiliser in the recommended doses. At luxurious growth, it becomes necessary to trim the plants and this should be done by removing entire shoots allowing light and nutrient to penetrate all the way down to the remaining shoots. CO2 enrichment always stimulates growth, but it is not really required to grow Pogostemon helferi successfully; the plant simply grows a bit slower. Pogostemon helferi thrives in a broad temperature interval from 23 to 30°C.

Pogostemon helferi is among the easiest foreground plant we have because it is not as light demanding as most other foreground plants; at low light, the individual stems simply grow a bit longer and the plant appears less compact. Try Pogostemon helferi together with other foreground plants such as Glossostigma or Hemianthus to create new and exciting color contrast in the aquarium.

Pogostemon helferi is relatively new in our hobby and thus, there is not much information available as yet. However, we recommend consulting the articles listed below if you want to learn more about this exiting plant.

Prasartkul A (2004) Pogostemon helferi (Hook. f.) Press (Lamiaceae), eine neue Aquarienpflanze aus Thailand. Aqua Planta 29: 143-148, in German

Tarepunda N (2005) Little Star, Aqua Star - The magnificent one Pogostemon helferi