Propagating Amazon Frogbit

How to propagate Amazon Frogbit (Limnobium laevigatum) from daughter plants on runners: dividing the floating mat, replanting offsets, and thinning fast surface growth.

Overview

Amazon Frogbit (Limnobium laevigatum) is a floating plant whose juvenile rosettes of round leaves lie flat on the water surface. Long trailing roots hang below, providing shelter for fish and fry, and the plant draws excess nutrients from the water column. It grows quickly and needs no substrate.

Propagation Method: Daughter Plants on Runners

Frogbit reproduces vegetatively through fragmentation of stolon (runner) segments. The mother rosette sends out short runners that produce daughter plants; the colony spreads across the surface like a connected web. Daughter plants eventually split off as independent floaters.

Step-by-Step

Let the surface mat grow until daughter rosettes form on the runners.
Identify a daughter plant that already has its own small roots and leaves.
Pinch or break the runner segment connecting it to the mother plant.
Float the separated daughter plant in the new tank or area, leaves up and roots down.
Keep the leaf tops dry and out of the filter outflow until it establishes.

Conditions for Healthy Growth

Lighting: low to moderate light is enough; it grows fast under good light.
Surface: calm water with minimal splashing on the leaf tops.
Nutrients: feeds from the water column, helping absorb nitrogen and reduce algae.
Water: comfortable around 20-28 deg C, pH 6-7.5; no CO2 needed.

Maintenance

Thin the mat regularly and remove clumps by the handful. Do not let the floating plants cover the entire surface, or they will out-shade plants below and reduce dissolved oxygen in the water.

Common Challenges

Water droplets sitting on top of the leaves can cause them to rot, so keep the tops dry and away from filter spray. Snails may eat the spongy underside of the leaves. Strong surface current can push the plants under and stunt or kill them.