If you’re interested in live plants, you’ve probably fantasized about growing a thick lawn of carpeting plants for your fish and shrimp to explore. If so, you really need to take a look at Dwarf Hairgrass, one of the easiest carpeting plants to grow!
What is Dwarf Hairgrass?
Hairgrass species are a little difficult to wrap one’s head around because there are so many kinds. Most of them are in the genus Elocharis. They are actually amphibious sedges, rather than true grasses and are found in marshy regions all over the world.
Their ability to grow both in and out of water makes them perfect plants for aquarists that want a grassy lawn appearance! Most of these plants grow quite tall, anywhere from 6 to 24 inches in height! Fortunately, we have Dwarf Hairgrass to create a lawn in even the smallest of aquaria.
Dwarf Hairgrass goes by one of two names in the hobby: Eleocharis acicularis and Eleocharis parvula. Whether they are two separate species or not remains to be determined by botanists.
The type strain can grow up to 6 inches tall. But then there’s Eleocharis acicularis/parvula ‘mini,’ a cultivar that does not grow beyond 3 inches tall.
This is the variety most people are interested in when seeking out Dwarf Hairgrass. So from here on out, know that I’m talking about the ‘mini’ variety!
- Common Names: Dwarf Hairgrass, Mini Hair Grass
- Scientific Name: Eleocharis parvula/acicularis ‘mini’
- Origin: Worldwide
- Height: 2-3 inches
- Growth Rate: Moderate
- Lighting: Medium to High
- Ease of Care: Easy to Moderate
Dwarf Hairgrass Care
Dwarf Hairgrass is a real favorite of mine because it works in nearly any setup. It will grow fairly rapidly if spaced properly and given plenty of light, fertilizer, and carbon dioxide. It will mostly fill in an aquarium bottom in 2 months, and grow even thicker over time if undisturbed.
It’s the perfect playground for nano fish and shrimp and also provides a safe haven for fish eggs, fry, and infusoria to develop. Unfortunately, Dwarf Hairgrass is not a plant you can just toss into the tank and forget about like Java Fern.
But if you’re looking to try slightly more challenging aquatic plants, Dwarf Hairgrass is a great place to get started!
Light Requirements
Hairgrass in general is very tolerant of a wide range of lighting, CO2, and fertilizer conditions. You can even keep them in low light aquariums with next to no added nutrients.
However they won’t do very much besides stay green. If you want them to get bushy, turn bright green, and spread across your tank, you need to encourage them with extra care.
Dwarf Hairgrass needs at least moderate lighting to spread. High lighting helps keep the plant compact, turns it a bright vivid green color, and encourages it to both spread and thicken.
However, not all lights are created equally. You need both light intensity and the right spectrum. Photosynthetically active radiation (PAR) is what fuels photosynthesis. WIthout the right light spectrum, plants can’t produce the sugars they need.
Fortunately, high powered full spectrum LED lighting is tremendously affordable nowadays. Adding a few fixtures on top of an aquarium goes a long way towards not only making the setup look better but also fueling plant growth.
Carpeting plants are especially light hungry because they are so far from the surface. It’s better to buy slightly more light output than you think you need if you’re getting into carpeting plants. The PAR levels at the substrate can be ½ to ⅓ that of the surface, depending on aquarium depth.
Other Plants & Substrate
It’s important not to choose plants that will shade out your Dwarf Hairgrass. A broad open expanse where they aren’t having to compete too strongly with other plants is recommended for a thick carpet.
Your Hairgrass will fill into the shadier spots as well. The runners linking them beneath your substrate allow well lit plants to share sugars with their shaded out neighbors to completely colonize the bottom.
Still, plants like Tiger Lotus, Red Root Floater, and other surface shading species are best avoided. Also be careful not to plant too many large, broad leaved plants like Amazon Sword plants, which will outcompete Hairgrass for light.
Standard aquarium sand, ADA Aquasoil Powder, Seachem Flourite Sand, and other fine substrates are much better for Dwarf Hairgrass than gravel. Personally, I’ve found Ada Aquasoil Amazonia Powder works incredibly well at growing Hairgrass. It’s rich with nitrogen and provides it right at the ground level where carpeting plants need it most.
With gravel, the large grains force the Hairgrass blades to grow with wider spaces in between them. Gravel is also harder to plant Hairgrass in whereas fine sand or clay is better at holding the thin roots in place.
That said, if gravel is all you have, you can still grow Dwarf Hairgrass. It simply will look patchy and may not ever take on a thick lawn appearance. Keep in mind that the large, sharp grains of gravel can also damage the fine roots of Hairgrass if moved by a gravel vacuum or digging fish.
Fertilizer, CO2, & Water Chemistry
If you want your Dwarf Hairgrass to spread, you’ll eventually have to provide additional supplementation. When using a rich plant substrate in a tank with fish to provide nitrogen, you won’t have to fertilize much or ever, besides whatever nutrients it doesn’t have.
If you’re using sand or some other inert substrate, you’ll need to use either plant tablets or water fertilization. I prefer plant tablets combined with a substrate that binds nutrients into itself like clay-based sand.
Tablets last for months rather than needing weekly dosing. However, aquatic fertilizers also work very well, especially ones rich in nitrogen.
A source of carbon dioxide is also really important for Dwarf Hairgrass if you want it to effectively carpet. CO2 is where plants gain most of the carbon they need to form their cell walls and other structural components. Unfortunately, the CO2 levels in water tend to be very low.
For aquariums 20 gallons or less, miniature pressurized CO2 systems are perfect. However for larger aquariums, you’ll want a citric acid or refillable CO2 system.
These don’t need to be super expensive but they can get pricey if you’re on a strict budget. If so, think about setting up a DIY CO2 reactor using yeast and sugar!
As you’d expect of a plant that grows all over the world, Dwarf Hairgrass is very undemanding when it comes to water chemistry. It can be grown anywhere from 60-84℉. It also thrives in both acidic or slightly alkaline conditions (pH 6.0-7.5). Lighting, substrate, and nutrients are far more important.
Aquascaping with Dwarf Hair Grass
Dwarf Hairgrass is one of the best foreground carpeting plants you can buy. Within just a few months you can have a nice, thick green lawn all over your tank. Therefore, you should use this plant for aquariums where you want to cover the substrate in green.
Avoid using other carpeting plants like Monte Carlo. They will form a tangled, competing mess with one another unless you continually prune them to keep things tidy.
However, larger carpeting plants like Pygmy Chain Sword Plants (Helanthium tenellum) work well since they leave space in between for the Hairgrass to grow in.
If you want to keep it from spreading into certain areas, you can place inert sand in those regions as a barrier. The Hairgrass will slow at that point, preferring to stick to the richer plant substrate.
Planting & Propagation
Unfortunately, planting Dwarf Hairgrass is a little time consuming. But if you take that time and do it carefully, you’ll be rewarded with a lush lawn.
When buying Hairgrass, your choices are either clumps/pots of fully aquatic grass or tissue cultures that come in little dishes.
I recommend buying your plants as tissue cultures. These are grown in sterile laboratory conditions in a nutrient gel solution. As a result they are guaranteed to be the right species and free of algae, snail eggs, leeches, or other hitchhikers.
They are usually grown in their emersed (out of water) form, though, which means there will be an adjustment period once you submerge them. They may show a bit of discoloration and may even melt back a little. This is quite natural; the plant has to reshape its biology for the aquatic environment.
You should pull apart your Hairgrass clump and use tweezers to press small clusters into your fine substrate. Leave around 2-4 cm of space between each cluster and try to get as much of the bottom covered as possible.
As long as you continue to provide it with the light and nutrients it needs, your Hairgrass should grow quickly to fill in the available space.
Another trick to get Dwarf Hairgrass carpet to grow in even faster is to use the Dry Start Method. There is several times as much carbon dioxide in the atmosphere as there is in standard water conditions.
Remember that Dwarf Hairgrass can grow above water so long as it’s kept moist. By growing it moist under high lighting you can provide it unlimited CO2 and no competition from other plants. A Hair Grass carpet can establish itself in as little as 6 weeks using the Dry Start Method!
Once you flood the tank, you may see some discoloration and dieback. But if you provide additional CO2 right at the start your Dwarf Hairgrass will rapidly recover.
Conclusion
As you may have guessed, Dwarf Hairgrass is one of my favorite carpeting plants. I always recommend it to aquarists that are looking for something that takes a bit more work than low light plants but will still reward your efforts.
The grassy lawn look gives any aquarium a polished appearance yet doesn’t take nearly as much effort as you might think. Dwarf Hairgrass is a great carpeting plant for beginners and I hope to hear from you if you decide to give it a try!
