Propagating Cryptocoryne cordata 'Rosanervig'

How to propagate the pink-veined broad-leaf crypt C. cordata 'Rosanervig' by runners and rhizome division while keeping its signature veining and surviving crypt melt.

Overview

Cryptocoryne cordata 'Rosanervig' is a broad-leaved cultivar of C. cordata famous for its olive-green leaves laced with pink veins. Like every crypt it is a rosette plant growing from a crown on a rhizome, so it is propagated vegetatively by runners and rhizome division, never by topping a stem. It is one of the slowest-growing crypts, so propagation rewards patience above all.

Plants are typically grown emersed before sale and convert to submersed growth in the aquarium. Importantly, runners from 'Rosanervig' keep the same intense pink veining as the parent, so vegetative propagation preserves the variety true to type.

Propagation Method (Runners / Division)

The main route is runners: an established plant pushes stolons under the substrate that produce daughter plantlets carrying the same pink venation. The second route is rhizome division of a mature multi-crown clump into separate rooted pieces. Because this cultivar is so slow, expect runners to take longer to appear than with faster crypts like wendtii.

Step-by-Step

1. Establish the parent in nutrient-rich substrate and let it grow undisturbed for an extended period.
2. Wait for stolons to emerge and form plantlets with their own pink-veined leaves and roots.
3. Once a plantlet is rooted, sever the connecting runner and lift it gently.
4. For division, lift the clump, rinse, and split the rhizome into pieces, each with a crown and roots.
5. Replant with roots buried, crown exposed, anchor lightly and leave undisturbed in shade.

Conditions for Healthy Growth

As a root feeder it needs an enriched substrate or root tabs. The signature pink veining is strongest under lower light and in leaner tanks, so resist the urge to over-light it. It does not require CO2. Keep temperature, lighting and chemistry stable, and let the plant settle in shade.

• Substrate: nutrient-rich, supplemented with root tabs.
• Light: lower light brings out the strongest pink veins; no CO2 required.
• Water: stable, soft and mildly acidic suits it well.
• Patience: among the slowest crypts; do not rush or relocate.

Maintenance

Minimal upkeep once settled. Trim only damaged or melted leaves at the base, refresh root tabs every few months, and leave the plant in place to let runners slowly build a patch. Avoid moving it, which is especially costly for such a slow grower.

Common Challenges

Do not discard a melting plant. The rhizome and roots stay alive and push out new submersed, pink-veined leaves within a few weeks to months if left planted. Cut decaying leaves at the base, hold parameters stable, keep it shaded, and wait it out.