Propagating Murdannia keisak (Marsh Dewflower) from Cuttings

Murdannia keisak is a fast, prostrate stem plant that roots readily at its nodes — propagation is as simple as snipping a stem and replanting it. Because the same fragmentation makes it a serious wetland invader in the US, this guide also covers how to dispose of trimmings responsibly.

Overview

Murdannia keisak, the marsh dewflower, is an annual emergent plant with succulent, prostrate stems 12 to 20 inches (roughly 30–50 cm) long. It naturally forms new roots at its lower nodes, which is exactly what makes it so effortless to multiply. In the aquarium it behaves as a fast, undemanding stem plant that grows both submersed and emersed, and is often used as a nutrient sponge in new tanks.

Propagation Method (Cuttings)

This plant is propagated by stem cuttings, taking advantage of its natural habit of rooting at the nodes. A trimmed top is essentially a ready-made new plant: once replanted, the lower nodes that contact the substrate quickly throw out roots, while the cut parent stem branches and sends up fresh side shoots.

Step-by-Step

Choose a healthy stem and cut the top 5–10 cm with clean scissors, ideally just below a node.
Strip the leaves from the lowest node or two so they will not rot under the substrate.
Push the bare lower section into sand or gravel deep enough to anchor it.
Keep the cutting in place; the buried nodes will form roots within days.
Leave the parent stem rooted — it will branch from the cut and produce new side shoots.

Conditions for Healthy Growth

Murdannia keisak is very easy to cultivate and grows rapidly under medium light without added CO2, in a sand or gravel substrate. It tolerates 18–28 °C, pH 6–7.5 and a wide GH range. Its semi-aquatic nature means it grows equally well emersed at the water's edge, where it produces three-petaled white to bluish-purple or pink flowers.

Trimming & Maintenance

Because growth is fast, trim roughly weekly to keep the plant tidy and to prevent it from overrunning slower neighbours. Each trim doubles as a propagation opportunity, since the removed tops can be replanted immediately.

Common Challenges

The main challenge is the plant itself: its vigour and node-rooting that make propagation trivial are the same traits that let it crowd out other plants. Keep it firmly in check and treat its disposal as seriously as its planting.