Propagating Echinodorus cordifolius: Plantlets on Arching Flower Stalks

How to propagate the large radican sword, Echinodorus cordifolius, from adventitious plantlets on its proliferating inflorescences and by rhizome division.

Overview

Echinodorus cordifolius, the radican sword or creeping burhead, is a stout perennial herb that grows up to 100 cm tall and develops rhizomes. Its emersed leaves dominate, with 5-6-ridged petioles 17.5-45 cm long and ovate to elliptic blades up to 32 cm bearing distinct translucent markings.

Native to Mexico, the West Indies, Central and South America (south to Paraguay) and the southeastern United States, it grows in marshes, swamps, ditches and ponds, blooming from spring to fall. Emersed plants readily produce flowers and seeds, but it can also be grown submersed.

Propagation Method (Adventitious Plantlets / Division)

As an Echinodorus, cordifolius is propagated by division or by adventitious new plants that develop on submerged flowering stems. Its inflorescences are decumbent to arching racemes of 3-9 whorls, up to 62 cm long, and are often proliferating — meaning daughter plantlets readily form along the flower stalk.

• Adventitious plantlets — daughter rosettes that develop along the arching, proliferating inflorescence and can be detached once rooted.
• Rhizome division — splitting the stout rhizome of a mature plant into rooted sections.

Step-by-Step

1. Let a mature plant send up its long, arching inflorescence; submerged or surface-level stalks favour plantlet formation over seed set.
2. Allow the proliferating whorls to develop daughter plantlets with their own leaves and roots.
3. Peg an arching stalk down to the substrate, or wait until plantlets root, then cut each one free.
4. Plant the daughter rosettes in a deep, nutrient-rich substrate, keeping the crown above the substrate.
5. To divide, lift a large plant and cut the stout rhizome into sections, each with roots and leaves, then replant.

Conditions for Healthy Growth

Echinodorus species prefer good light and grow best in a deep, nutrient-rich substrate; as a large, heavy root feeder, cordifolius benefits from generous root tabs. Under good light it readily forms aerial leaves above the waterline, so it is best in open-top or very deep tanks.

Maintenance

Remove old or oversized outer leaves at the base to control this vigorous plant's footprint and keep light reaching the substrate. Replenish root tabs regularly and thin detached plantlets, as cordifolius grows fast and can quickly dominate a layout.

Common Challenges

• Emersed-to-submersed transition: with submersed leaves mostly absent in nature, plants may shed emersed foliage and regrow submersed forms after planting.
• Outgrowing the tank: at up to 100 cm tall this is a background or open-top plant, not a midground specimen.
• Seed instead of plantlets: emersed inflorescences readily set flowers and seeds, so keep stalks submerged or near the surface to favour adventitious daughters.