Dwarf sagittaria

Overview

Dwarf sagittaria (Sagittaria subulata) is the easy, low-tech grass carpet — short, grass-like blades that spread by runners into a low green lawn without demanding CO2. It looks much like dwarf hairgrass but is far more forgiving, making it one of the best foreground and midground grasses for beginners. Give it medium light and it quietly fills the front of the tank on its own.

Planting & placement

Plant dwarf sag with the roots in the substrate and the crown (where blades meet roots) at the surface — burying the crown causes rot. Space small clumps across the foreground or midground and let the runners knit them together. It is a root feeder, so root tabs help in inert gravel. See how to plant aquarium plants for crown depth, and aquascaping for beginners for layout.

Light, CO2 & ferts

Medium light keeps dwarf sag low and carpeting; in dim light it stretches taller. It needs no CO2, which is its big advantage over high-tech carpets — though CO2 does make it faster and more compact. Feed root tabs plus a light liquid dose. For light recommendations see best light for a planted tank.

Propagation & problems

Dwarf sagittaria propagates by runners, sending daughter plants up through the substrate to thicken the carpet. To expand or control it, lift the young plants and replant where wanted. The main issues are a buried crown causing rot (keep it at the surface) and taller-than-wanted growth in low light (raise the light). For a taller background grass to layer behind it, see vallisneria. Because it carpets without CO2 and tolerates cooler water, dwarf sagittaria is also a good grassy choice for coldwater and goldfish tanks where high-tech carpets would struggle. Thin the runners occasionally to keep the lawn from creeping into the rest of the scape, and it stays a tidy, low-maintenance foreground. If the blades start reaching for the surface, that is the plant telling you it wants brighter light to stay carpet-height. Otherwise it asks for almost nothing beyond the odd root tab.