About the species

Helanthium tenellum 'Green' is a tiny sword plant that forms a grass-like carpet five to ten centimetres deep. It spreads by runners and gradually fills out the area with new small rosettes. Unlike ordinary Helanthium tenellum, which turns red-brown, 'Green' keeps its fresh green colour even in strong light. The species used to be called Echinodorus tenellus.

Facts

• Latin name: Helanthium tenellum 'Green'
• Plant type: Runner plant
• Origin: Cultivated variety
• Height: 5–15 cm
• Growth rate: Slow
• Position: Midground

Light requirement

Low light requirement. It manages with the lighting that comes with most aquariums and is happy in partial shade behind or beneath taller plants. Strong lighting does not harm it, but raises the risk of algae on the leaves because the plant cannot use all the available light.

CO₂ & nutrition

Manages entirely without added CO₂, which makes it as suitable for a simple aquarium as for an aquascape. Liquid carbon or injected CO₂ speeds up growth but is never a requirement. Dose an all-round fertiliser with iron and micronutrients every week.

Planting

Plant the individual plants with their roots in the substrate and the crown free above it. The plant then spreads by itself with runners beneath the substrate and gradually fills out the area, so leave room around each plant from the start.

Rinse all the gel off in lukewarm water before planting, otherwise it can cause bacterial cloudiness. The cup holds many small plants — divide them up and plant them in several portions.

Care & propagation

Thin the runners where you do not want them and move the daughter plants where you want more. Cut them free with scissors rather than pulling, so the mother plant's roots stay put. A nutrient-rich substrate makes it spread considerably faster.

Position in the aquarium

Its height makes it a classic midground plant. It works nicely as the transition between low foreground plants and tall background plants, and looks best in a group or around a piece of wood.

Difficulty level

🟢 Easy — grows in most aquariums without CO₂ and under ordinary lighting.

Delivery format

Delivered as 1-2-Grow! — a laboratory-grown cup holding many small plants in nutrient gel. Because the plant is cultivated in vitro it is completely free of snails, algae, planaria and pesticides, which makes it the safest choice for a shrimp aquarium.

Recommendation

An easy and affordable way to get a lawn without CO₂, and rewarding in shrimp aquariums where the shrimp like to graze among the blades. Give it a nutrient-rich substrate — that is what decides whether the carpet ends up sparse or dense.