Care guide · Freshwater · plants

Straight vallisneria

Vallisneria spiralis

Photo: Lara Gudmundsdottir · Source · CC BY-SA 4.0Resized and compressed; no cropping or colour changes.

Vallisneria spiralis grows long ribbon leaves from a rosette and can create a green curtain along the back of an aquarium. Runners gradually extend a single planting into a strip or bed. This shelters fish but requires space management. Spiralis does not mean every leaf should be curled; the name relates to its reproductive structures. Do not choose it as a permanently low foreground plant. Leaves may reach the surface and shade neighbouring plants. A correctly positioned root base, suitable nutrition and selective thinning make it useful in a relatively simple planted tank, provided its eventual spread is considered from the start.

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At a glance

Difficulty: Easy
Plant height: Up to 100 cm
Growth rate: Fast
Placement: Background
Temperature: 18–28 °C
pH: 6.0–9.0
Light: Moderate, High
CO₂: Optional
Nutrient uptake: Through roots and water
Substrate: Sand, Gravel, Aquasoil
Propagation: Runners

About this plant

Kew accepts Vallisneria spiralis. Several Vallisneria species and selections appear under similar trade names, so leaf width and length alone do not fully establish identity. This guide does not automatically cover every curled or giant vallisneria. Leaves emerge from a shared rosette base. Unlike stem cuttings, arbitrary leaf fragments cannot simply be replanted to make new complete plants.

Natural habitat

Vallisneria spiralis is a submerged plant from warmer parts of the Old World. It can form extensive vegetation in suitable freshwater habitats. Ribbon leaves move with the water and provide cover without a branching structure. In an aquarium, room for the leaves matters more than imposing strong current. Keep open feeding, swimming and bottom-dwelling areas beside the background strip.

Placement in the aquarium

Cultivation guidance is 18–28 °C and pH 6–9. Leaves can reach about 100 cm in length; this is growth potential, not a prediction for every tank. Use the background. Insert roots into the substrate but keep the rosette base at its surface. Allow runners room without losing maintenance access. Prevent leaves from covering outlets, intakes and feeding areas.

Light

Moderate to high light fits the cultivation guidance used here. Consider depth: a bright-looking surface does not establish illumination at the bottom. Dense surface leaves also create shade. A general start with 6 hours can progress towards 8 hours in stable conditions. No reliable species-specific PAR range is available to automatically approve every lamp. Assess intensity, coverage and maintenance together.

CO₂

CO₂ is optional. Vallisneria can grow without injection, so equipment is not a default requirement. Existing injection should suit lighting, nutrients and animals. Liquid products marketed as carbon are not equivalent to controlled CO₂ gas supply. Assess their own instructions and suitability instead of increasing doses to force a newly planted rosette to establish.

Nutrition and fertilisation

The root zone matters for this rosette plant. Suitable root feeding may help in depleted sand or gravel, alongside nutrients already in the water. Both macro- and micronutrients contribute; iron is only one component. A nutrient base without nitrogen and phosphorus does not supply all macronutrients. Check substrate, stocking and maintenance before combining products. Demand changes as a small plant becomes a bed.

Substrate and root feeding

Use an anchoring substrate without burying the rosette base deeply. A covered nutrient layer is one approach, not the only one. Root tablets may be used selectively if an appropriate product and genuine need exist. Aquasoil can alter water chemistry and is not automatically an improvement for a plant also suited to harder water. Match the whole aquarium.

Growth and pruning

Established plants may produce leaves and runners quickly. Remove damaged or excessively long leaves selectively near the base. Cutting every leaf tip to the same height leaves damaged edges and does not replace thinning. Remove excess daughter plants when crowded, protecting roots that should remain. After pruning, reassess how much more light reaches lower planting.

Propagation

Runners connect the mother plant to young rosettes. Allow independent roots and leaves to develop before exposing and cutting the connection carefully. Avoid pulling an entire chain from the substrate. Replant with the base exposed. A long leaf lacking a growing base cannot become a new Vallisneria. Preserve some established shelter when relocating a group.

Suitable fish and animals

Leaves provide small fish with sheltered routes along the background. Active shoals still need open swimming space. Bottom dwellers can move between spaced rosettes, but large diggers may uproot young plants. Herbivores can damage leaves; rapid growth does not guarantee recovery keeps pace. Central links consider practical use and water overlap without endorsing all listed species together in a small tank.

Possible problems

Old leaves may deteriorate after transplanting while the base survives. Look for firm new foliage and check that the rosette is exposed. Stalled growth may involve surface shade, depleted substrate or disturbed roots. Investigate before raising iron or CO₂. Remove leaves from the filter intake and clear decay. Keep runners managed so maintenance remains possible.

Care for this plant

Plant fertiliser

Nutrient substrate

Tools

Prices from the latest retailer update, excluding shipping. Check stock and delivery with the retailer.

Lighting has been investigated but is not yet linked: available specifications do not adequately establish light class and coverage at plant depth.

Sources & review

This care guide draws on several specialist sources and was last checked on 8 October 2026.

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