Propagating Cryptocoryne undulata 'Broad Leaves' by Runners and Division

How to propagate the broad-leaf Cryptocoryne undulata: a hardy rosette crypt that spreads by runners and rhizome division, often melting then regrowing after replanting.

Overview

Cryptocoryne undulata is a hardy rosette crypt found in Sri Lanka and Thailand. The 'Broad Leaves' variant carries broader, strongly wavy leaves; mature plants of the species can grow long, ruffled dark green leaves to more than 35 cm. It is considered one of the easier cryptocorynes to grow and is common in the aquarium trade.

It prefers bright light and a temperature range of 22-28 °C (72-82 °F), grows well both partially and fully submersed, and flowers relatively easily — a good sign of a settled, healthy plant ready to propagate.

Propagation Method (Runners / Division)

Cryptocoryne undulata propagates vegetatively: the 'diploid' form forms runners. These runners travel through the substrate and push up new daughter plants a short distance from the mother. A mature clump's rhizome can also be divided into sections, each with roots and leaves, to make additional plants.

Step-by-Step

Let a mother plant establish firmly in nutrient-rich substrate and grow undisturbed.
Watch for runners pushing up daughter plants nearby; let each develop its own leaves and roots.
To divide, lift a mature clump and cut the rhizome into sections, keeping roots and several leaves on each.
Replant the runner offsets or rhizome divisions into the substrate, burying the roots but keeping the crown exposed.
If leaves melt after replanting, leave the rhizome in place and wait — new growth typically follows.

Conditions for Healthy Growth

Temperature: 22-28 °C suits it well.
Lighting: it prefers bright light; lower light produces lighter green foliage.
Substrate: nutrient-rich; as a root feeder it benefits from feeding through the roots.
Growth form: thrives both partially and fully submersed.

Maintenance

Once established, the broad-leaf crypt needs little attention. Remove fully melted or rotting leaves so they do not foul the water, and thin runner offspring if the midground becomes crowded.

Common Challenges

The classic challenge is crypt melt triggered by transplanting or parameter changes. Resist the urge to uproot a melting plant — the rhizome usually recovers. Pale, lighter foliage points to insufficient light rather than disease.