Hairgrass

Hairgrass

Hairgrass, botanically Eleocharis vivipara, is a tall, grass-like spikerush native to marshes, pond margins, and slow streams of the southeastern United States and Central America. Unlike the low-growing carpeting hairgrass species, this is a background grass, sending up long, hair-thin blades that sway gently in the current and form an airy, meadow-like curtain at the rear of the aquascape. It is also sold under the names Giant Hairgrass, Tall Hairgrass, and Umbrella Hairgrass.

Care tip: Plant Hairgrass in a nutrient-rich substrate, as it feeds heavily through its roots. Moderate to strong lighting keeps growth denser and more compact; under low light the blades grow thinner and reach for the surface. Trim old outer blades at the base as they brown, and expect new plantlets to appear at the tips of mature leaves rather than from spreading runners.

Growing 12 to 24 inches tall, Hairgrass is one of the few Eleocharis species suited to background placement rather than foreground carpeting. It propagates by a distinctive method: rather than spreading through underground runners like most hairgrass species, it produces small plantlets directly at the tips of its leaves, which can be separated and replanted to start new clumps. CO2 injection is not required but noticeably improves density and growth rate, and root tabs placed near established clumps support the plant's root-feeding habit. New plantings often melt back and shed older growth as they transition from emersed to submerged form — this is normal, and fresh blades follow within a few weeks.

In the aquascape, Hairgrass is best planted in clusters of five to ten stems along the back glass or behind hardscape, where its fine texture softens the hard lines of rock and wood and adds a natural, riverbank feel. The narrow blades create a strong visual contrast against broad-leaved midground plants like Anubias, Bucephalandra, and Cryptocoryne, and the gentle swaying motion in current brings continuous movement to an otherwise still background. It also offers cover for shrimp and fry along the tank's rear zone.

Because it tolerates a wide range of water conditions and does not require CO2 to survive, Hairgrass is a forgiving choice for aquarists who want the height and texture of a background grass without the intensive demands of true carpeting Eleocharis species. It is best suited to tanks of 20 gallons or larger, where there is enough vertical space for the stems to reach their full height before trimming.

Care & Specifications