Giant Hairgrass on the Surface:

Giant Hairgrass (Eleocharis montevidensis) is a rooted spikerush native to sandy lake shores, riverbanks, and wet meadows from the central and southern United States to South America. It spreads by runners into dense clumps of slender, upright stems that grow well above the leaf litter bed. In the Botanical Method Aquarium, these thickets provide refuge for fry, shrimp, betta fish, and other small fish, along with surfaces where biofilm can encrust.

Essential Details

• Care Level: Easy
• Growth Habit: Rooted, spreads via runners into dense clumps
• Light: Low to Medium
• CO2: Not Necessary
• Propagation: Runners and division
• Tint Tolerance: Low to High
• Habitat Location: Central and southern United States to Central America, and South America from Peru to Uruguay
• Optimal For: Betta fish, shrimp, rasboras, and small tetras
• Use with Caution: Rinse before introducing; may carry beneficial hitchhiking snails, snail eggs, or duckweed from the grow-out ponds
• Size Range: 16 to 18 inches tall
• Quantities: Potted

Giant Hairgrass for Planted Aquariums & Blackwater Biotopes

Giant Hairgrass absorbs most of its micro- and macronutrients through its roots, so it grows best in a dirted aquarium or an inert sand substrate with root tabs. We separate each pot into small tufts and plant them a few inches apart between the leaf litter. Runners spread out from each tuft and root new stems into the perpetual substrate. As the clumps fill in, biofilm encrusts the stems and becomes a grazing resource for shrimp and our fishes, what we call supplemental nutrition.

The darker the tint in your aquarium, the less light reaches your plants, and light dictates how quickly Giant Hairgrass spreads. Under low light it fills in slowly, and medium light encourages its runners to extend faster. CO2 injection is optional and can speed growth. Aquasoils absorb tannins from the water column, so an inert sand substrate with root tabs keeps the tint your botanicals release and the nutrients this plant needs at its roots.

Runners travel through the substrate from the base of each clump and send up new stems as they go. Its stems can reach the surface nano aquariums, so we place it along the back of mid-sized and larger aquariums. To keep open swimming space for bettas, rasboras, and small tetras, we thin clumps by slowly lifting them out of the substrate, which keeps clouds of dirt out of the water column. Excess plants go to the compost, and we never release aquarium plants into local waterways.

Beneath the Leaves: Eleocharis montevidensis in the Wild

Eleocharis montevidensis is a spikerush, a member of the sedge family. Its slender green blades are its stems. Like every Eleocharis, its leaves are reduced to small sheaths wrapped around the reddish stem base, so the stems carry out photosynthesis. In the wild it grows at the water's edge with its stems standing above the mud, and waterfowl and shorebirds eat the whole plant. Its species name refers to Montevideo, Uruguay, near the southern end of its range.

Where a botanical contributes as it breaks down, an aquatic plant is living and contributes as it grows. So let them grow. Mother Nature leads the way.

Sustainability Note:

Please select a heat/cold pack if necessary. Check your local weather before ordering to avoid any shipment holds or cancellations. All Plants may contain snails or snail eggs. We keep them in all of our aquariums for the benefits they provide. Our blackwater aquarium plants are provided in cooperation with PNW Bettas in adherence to their Shipping and DOA Policies. Your curated selection will arrive in their packaging separate from your botanical, wood & merch orders.