Photo: Robert H. Mohlenbrock / Public domain

Dwarf Hairgrass Care

Eleocharis parvula · Cyperaceae

🐾 Pet-safe 🎯 Moderate ☀️ Medium, bright indirect 💧 Every 7 days

🕮 6 min read 🕓 Last reviewed: 2026-08-23

Care at a glance

Light

Medium, bright indirect

Temperature

20–26 °C (68–79 °F)

Soil

a nutrient-rich aquarium substrate (or attached to wood/rock)

Difficulty

Moderate

Mature size

4–15 cm (2–6 in)

Pet safety

Pet-safe

Care effort High

The short version

A little attention keeps it happy.
Give it Medium, bright indirect.
Water every 7–7 days.
Safe around cats and dogs.

The Dwarf Hairgrass (Eleocharis parvula) is an aquatic plant grown submerged in freshwater aquariums. It comes from Cosmopolitan and is rated Moderate to keep, reaching 4–15 cm. Here is how to grow it underwater — lighting, substrate, CO₂, placement and propagation.

Also known asEleocharis parvulaショートヘアーグラス迷你牛毛毡Pelo de elfo enanoGazon aquatique nain

📋Quick facts

Growth rate	Moderate
Mature size	4–15 cm (2–6 in)
Native region	Cosmopolitan
Plant family	Cyperaceae
Toxicity	Non-toxic
Air-purifying	No
Ideal for	homes with pets

⚖️Pros & cons

Pros

Non-toxic to cats and dogs
Compact — fits a desk or shelf

Cons

Needs high humidity to look its best

🐟Growing it in an aquarium

Keep the water at 20–26 °C. Stable, gently moving water and regular partial water changes keep it healthy; sudden swings in temperature or chemistry cause melting.

Light

Give it Medium, bright indirect-equivalent aquarium lighting. Low-tech tanks suit undemanding species; brighter light (and often CO₂) brings out the best colour and compact growth but also feeds algae, so balance it carefully.

Soil

Plant it in a nutrient-rich aquarium substrate (or attached to wood/rock). Rooted species are hungry feeders — use root tabs or a liquid aquarium fertiliser (and CO₂ for demanding types). Epiphytes like Anubias, Java fern and Bucephalandra must NOT be buried: tie or glue their rhizome to wood or rock, or they rot.

Its size and habit suit a spot in the foreground, midground or background depending on how tall it grows; trim and replant tops to keep it dense.

✂️How to propagate, step by step

Spring and early summer, during active growth, give the best success. Here is how to do it, step by step:

offsets (pups)

Wait until the offset (pup) is about a third the size of the parent.
Unpot the plant so you can see where the pup joins it.
Separate the pup, keeping as many of its own roots as you can.
Let any succulent cuts callus for a day; pot rooted pups straight away.
Plant in suitable mix and water lightly until it establishes.

division at repotting

Water the plant the day before to reduce stress on the roots.
Slide it out of its pot and gently shake off the loose soil.
Tease the root ball into sections, each with healthy roots and a few shoots.
Pot each section into fresh mix at its original depth.
Water them in and keep out of direct sun for a week while they recover.

🔬Classification

Plant type	Aquatic plant
Genus	Eleocharis
Family	Cyperaceae · Cyperaceae
Native to	Cosmopolitan

🩺Common problems

Symptom	Likely cause	What to do
Algae on leaves or glass	Too much light or excess nutrients in the water	Cut the lighting period, reduce feeding, and add algae-eating clean-up crew.
Melting or dissolving leaves	Shock from a new tank (common when settling in)	Be patient — trim mushy leaves; new submerged growth usually follows.
Brown, crispy tips	Dry air, or salts and fluoride from tap water	Raise humidity and water with filtered or rested water.

🩺 Plant Doctor →

🐛Pests & prevention

The usual indoor pests are spider mites (fine webbing, speckled leaves), mealybugs (white cotton-wool tufts), scale (small brown bumps), and fungus gnats (tiny flies from soggy soil). Inspect any new plant before it joins the others, wipe the leaves now and then, and let the topsoil dry to keep gnats away. At the first sign, isolate the plant, wipe or rinse off what you can, and treat with insecticidal soap or neem oil every week until it is clear.

🐾Is it safe for pets?

Good news for pet owners: the Dwarf Hairgrass is considered non-toxic to both cats and dogs by the ASPCA. It is one of the safer choices for homes with animals, though eating any plant can still cause mild stomach upset.

Toxicity information is a general guide based on ASPCA data. If your pet or child may have eaten any part of a plant, contact a vet or poison control right away.