Pogostemon helferi
Downoi

Description

Background History

Pogostemon helferi is one of the most unique and beautiful foreground plants available to hobbyists.  There is no mistaking Pogostemon helferi. The distinctive curly green leaves serves as an attractive composition compared to with other plants in the aquarium. 

Found originally in waterways of Thailand and Myanmar, Pogostemon helferi first made its way into the aquatic plant hobby in 2006.  It grows naturally intermixed with riparian vegetation alongside creeks, streams and riverbeds.  When first introduced to the hobby, this plant had a notorious reputation as being a difficult plant to grow and reproduce. As hobbyists learned more about the plant, Pogostemon helferi became moderately easy stem plant to grow, and propagate.

In Thailand, this plant is called “Dao Noi” which translates into English as “Little Star”.   Hobbyists have adopted this nickname and now Pogostemon helferi is commonly known as Downoi.  

Growth Characteristics

Pogostemon helferi is a stem plant that has short distances between its internodes which helps create the look of a compact bush.  This plant will grow to 2 inch (5 cm) tall underneath high light, but will grow slightly taller (5 inches) in moderate lighting conditions.   It prefers a fertile substrate bed, at least moderate lighting, and some carbon dioxide to do well.  Its growth rate is moderate for a stem plant.  Pogostemon helferi will continue to stay short, yet small side shoots may appear every two weeks and will grow to full size in an additional three weeks. 

The distinctive curly leaves are a vibrant green color and reach a length about 1 inch (2.5 cm).  Yellowing or pale green leaves are direct signs of iron deficiency or insufficient lighting.  It is important to thin out and replant excess growth on Pogostemon helferi stems to ensure adequate lighting reaches these leaves.

Propagation is easily done through replanting side shoots.  Trim each side shoot and replant directly into the substrate bed.  A network of roots will form approximately 2 inches (5cm) below the substrate.  In taller stalks of Pogostemon helferi can be divided in half to encourage side shoots to sprout from the leftover bottoms.

Aquascaping Application

Pogostemon helferi is a versatile plant that can either be kept in small three stem groups to accentuate an aquascape, or it can be kept in larger groups to serve as a carpet plant.  Since the curly leaf characteristics of this plant are so different from other aquatic plants, aquascapers may utilize Pogostemon helferi as a “flash” accenting factor in their layouts.

When initially planting Pogostemon helferi, provide approximately ½ inch spacing (1 cm) between each stem.  Within a matter of weeks, Pogostemon helferi will expand and fill in the open areas.

The small stature also contrasts well in front of rocks and other hardscapes.

Photo Credit: Alex Korakis

Plant Profile
Scientific Name: Pogostemon helferi
Common Name: Downoi
Difficulty: Moderate
CO2 Requirements: Moderate
Lighting Requirements: Medium
Plant Arrangement: Foreground
Growth Rate: Moderate
Family: Acanthaceae
Genus: Pogostemon
Origin: Southeast Asia
Plant Type: Bulb
Water Hardness: Medium (GH = 9-13 dH)