Propagating Sagittaria Pusilla 'Brazil' from Runners

How to multiply Sagittaria subulata 'Brazil' through stolon runners and daughter plants to build a grassy foreground carpet in a low-tech freshwater tank.

Overview

Sagittaria pusilla 'Brazil' is a compact locality form of Sagittaria subulata, a perennial herb of the Alismataceae family that in nature grows in shallow water along coasts, marshes and estuaries. In the aquarium it stays low, sending up narrow grassy blades, and is prized as a hardy transition plant between the foreground and midground. Because it spreads on its own through underground runners, it is one of the simplest grassy plants to propagate.

Propagation Method (Runners)

Sagittaria subulata propagates via stolons, also called runners: thin horizontal stems that creep across or just under the substrate and produce a small plantlet at the end. Over time these connect into a long chain of plants, filling the bottom of the tank. Even a single plant can quickly reproduce using its string of underground runners.

Step-by-Step

Plant the parent in nutrient-rich substrate, pushing the roots down but leaving the base of the leaves uncovered.
If a pot contains several individual plants, separate them and leave a little space between each so they have room to spread and multiply.
Let the plant settle and grow; healthy specimens push out horizontal runners that travel through the substrate.
Each runner produces a daughter plantlet that develops its own roots at the tip.
Once a daughter plant has anchored and grown a few of its own leaves, you can leave it in place to thicken the carpet, or gently sever the connecting stolon and replant it elsewhere.

Conditions for Healthy Growth

This is a root feeder, so the most important factor is a nutrient-rich substrate or root tabs placed near the base. Lighting controls height: it tends to stay short under bright light but can grow noticeably taller in dimmer conditions, so use stronger light if you want a tight low carpet. It tolerates a wide range of temperature and hardness and does not require added CO2.

Maintenance

Once established the plant fills in on its own. Thin the carpet periodically by lifting and replanting wandering daughter plants where you want more density, and remove any old or yellowing blades. Top up root fertiliser as the bed matures to keep new runners coming.

Common Challenges

Plants stretching tall and leggy — usually too little light; increase intensity to keep them low.
Slow or no runners — typically a poor or exhausted substrate; add root tabs to feed the roots.
Covering the leaf base when planting can cause rot, so keep the crown above the substrate.