🌱Dwarf Hairgrass Care Guide (Grow a FULL Carpet in 4 Weeks)

dwarf hairgrass header

Having a beautiful carpet plant in your aquarium is a must if you’re aiming for a professional-looking aquascape. Consider this post as your ultimate cheat sheet for dwarf hairgrass care.

Generally speaking, the dwarf hairgrass is not a difficult aquatic plant to look after but there are a couple of tricks you should definitely be aware of before proceeding. Many hobbyists approach the planting wrong and that’s absolutely essential for successful growth.

I discuss that in detail below, as well as other hairgrass peculiarities, so let’s not waste more time and jump straight to the facts.

Introduction and Overview of Dwarf Hairgrass (Eleocharis parvula)

There are 3 plant species of underwater-tolerant dwarf hairgrass, that are available in the aquarium trade.

These are namely the Eleocharis parvula, Eleocharis acicularis ‘Mini’, and Eleocharis Belem which remains the smallest of all three.
dwarf hairgrass carpet
The most popular choice is E. parvula, also known as dwarf spike-rush, because of its faster growth rate and decent maximum height. This species of hairgrass gives aquarists the flexibility of choosing the carpet’s ‘presence’ in their aquascape.

The other two types are slow-growers and remain small overall. For this reason, I recommend resorting to them if you’ll be keeping nano fish or invertebrates in a rather small tank such as a shrimp bowl.

In general, aquatic carpeting grasses are known to be picky growers and require intensive care.

The dwarf hairgrass, however, is more beginner-friendly in that regard.

By following a couple of simple care tips, you’ll be able to successfully cover the bottom of your fish tank with a lush green mat.

Don’t get me wrong though, this plant will still demand your attention and a healthy dash of regular maintenance is a must.

However, I can guarantee you that the results will be worth it.

Once you get yours growing it will thrive almost on its own and it will cover all of your planted tank’s free landscape.

Here’s how a fully-established blanket of dwarf hairgrass looks like in an aquarium:

How to approach dwarf hairgrass planting the proper way?

There are a couple of very important steps that you’ll need to follow in order to give this plant a proper kickstart. I’ve perfected the process with a couple of subtleties that I’ve found through my own experience, and by monitoring the fish tanks of my clients. Here’s my refined guide on how to plant the dwarf hairgrass in a step-by-step manner:

  1. Divide the hairgrass into patches of 4 to 6 blades of grass. If you use bigger patches you’ll significantly slow down the spread speed of the grass. When using very thin packs the roots and the so-called runners won’t compete with each other and your hairgrass will form a cover much, much faster.
  2. Trim the roots. Trimming the roots will guide the energy of the plant to recover the roots faster. As this type of hairgrass spreads through runners, this is beneficial to a faster spread of the carpet.
  3. Grab the hairgrass by the roots with a pair of plant tweezers. Using planting tweezers is somewhat mandatory for planting virtually any type of hairgrass in an aquarium. Fingers won’t be enough and you’ll experience significant difficulty as they lack the finesse. Make sure yours are made from stainless steel. I can recommend using these or similar ones, as they’ve done well by me so far.
  4. Place each patch 1/2 or 1 inch apart. One inch is enough space to stimulate the runners to grow without overcrowding the patches.
  5. Push the patches gently into the substrate. Hold the tweezers at a 45-degree angle and apply a slight push to the substrate.
  6. Shake and pull the tweezers out when the patch is 1/3 deep. Shaking is recommended so the substrate can fit itself around the roots of the grass. This way you can safely pull out the tweezers without uprooting the fragile blades of grass.

And you’re done.

The dividing procedure typically takes me forever and it’s kind of annoying so arm yourself with patience.

However, using no more than 6 blades per clump will achieve the fastest growth and spread according to my experience.

Spending half an hour will save you weeks of slow spread in the long run, so it’s definitely worth it.

What to expect after the initial planting?

It’s normal for Eleocharis parvula to start browning at first. Worry not! This is because, often, merchants grow the grass emerged:

These yellowing blades are not used to the underwater conditions and the more fragile ones will fade in the beginning.

What you want to do at this stage is trim.

Trimming will encourage lateral spread through more runners and also the emergence of new shoots.

The new blades will be acclimated to being fully submerged and won’t go brown over time.

When trimming you’ll get rid of the withering growth which will force the grass to employ its energy in making new, fresh shoots.

With proper care, your DHG should double within a month or so. You’ll witness new runners in just about a week if everything’s going fine.

If you’ve followed my planting process you can expect a 90%-dense cover between patches at the end of the 4th week.

Not bad, right?

The 4 secrets of growing your own hairgrass carpet

It’s simple really. A beautiful, lawn-like carpet of dwarf hairgrass requires four things:

  1. Moderate to high lighting.
  2. A healthy dose of fertilizer.
  3. CO2 is not of utmost importance, but definitely highly beneficial.
  4. Trimming
Let me expand a little on these.

1) Lighting and tank depth:

Being a carpeting type of plant it’s understandable why dwarf hairgrass would have higher requirements in terms of lighting.

The deeper your tank, the harder it is for light to penetrate right down to the bottom.

But before you start thinking about PAR readings and whatnot I suggest that you pay a visit to my guide on aquarium lighting.

There you’ll find that it’s all about PUR (Photosynthetic Usable Radiation) and LED lights are doing great at providing the right amount of PUR for your plants.

Just take your tank’s depth into consideration.

If you go over to that post you’ll find that I’ve discussed in detail all aquarium sizes and the appropriate lighting fixtures for each of them – low, medium, and high intensities.

Different tank sizes will demand a different lighting model.

Find your tank’s size and pay attention to the “medium” and “high-tech” lights recommendations.

Since the aforementioned post is on lighting overall, if you’re being serious about your plants you should probably go more in-depth.

I have a complete starter’s walkthrough on that which took me 5 days to put together.

There, I tried to cover everything that considers lighting for aquarium plants, including some well-spread false beliefs considering spectrum and intensity.

Make sure you know these before going after difficult plants, by giving my guide a skim.

Also, please don’t fall for the “watts per gallon” myth!

2) Fertilizers:

When it comes to fertilizing your dwarf hairgrass, it is worth noting that it will greatly appreciate the main macronutrients – Nitrogen, Phosphorus, and Potassium.

There’s an ongoing debate among fishkeepers if the plant prefers being fed through fertilizing the water column or through the substrate.

In my experience, it does better with a nutrient-rich substrate.

The only evidence I have for that is my own personal observations so there’s that.

To help you with understanding substrates better I wrote this guide on the matter.

I’ve had enormous success with ADA’s Aquasoil (link to see the stuff on Amazon) and I’d rather stick to that as my primary recommendation.

It’s probably safe to assume that the Carib Sea Eco-Complete will also work here, as long as you’re supporting it with a healthy dose of root tabs.

In my black sand-based fish tanks, I use these root tabs called Seachem Flourish and I’m also pretty happy with the results.

Liquid fertilizers are okay, however, if you’re a fan of that.

Bottom liner – use some kind of good aquarium fertilizer and make sure it’s providing the N-P-K macronutrients. Visit the link to learn which ones contain the key nutrients for the best plant growth possible.

Here’s a nifty secret: dwarf hairgrass REALLY loves iron. Dosing some iron can make a difference in your end results.

3) CO2:

As with most aquatic plants, injecting some CO2 will definitely benefit dwarf hairgrass:

At a rate of 1 to 3 bubbles per second or around 30 ppm, you will achieve faster, denser growth and a brighter lush green coloration.

For the best results, you’ll want to have a CO2 regulator with a solenoid that is synchronized with the timer of the aquarium’s lighting.

The regulator should also have a durable needle valve for a more precise bubble count.

If you don’t know what I’m talking about, you should probably check my guide on CO2 regulators for aquarium use.

Anyway, you can grow it without CO2 injection, but it will take your carpet longer to establish.

However, time aside, for a satisfying end result I think that lighting combined with the right balance of nutrients will have a greater impact on DHG than CO2 injections.

That’s just my personal experience.

Supplying CO2 will suppress any algae growth though, which can definitely emerge with the combination of high lighting and nutrient-rich fertilizers.

Author’s note: If your hairgrass has a bit of a flow going (very light, not to cause uprooting) it will be way more difficult for algae spores to attach themselves to it.

4) Trimming:

In the carpeting phase, you’d want to trim your DHG whenever it grows taller than around 2 inches.

Cutting it back to 1.5 inches encourages the horizontal spread and you’ll have a lush green carpet way sooner than without regular trimming.

If left uncut the E. parvula variety of dwarf hairgrass will reach a height of about 4 inches (or around 10 centimeters).

Anyway, one of the most common issues with any carpeting plant is the lack of lateral growth.

If you have issues with getting Dwarf Hairgrass to spread then you should trim even deeper.

I learned this the hard way, but interestingly enough not through looking after carpeting plants:

My first house plant was Spathiphyllum, a plant better known as Peace Lily.

Even though I got the Spathiphyllum because my research showed that it requires little care I still managed to almost kill it.

Long story short, all of its leaves and stems withered.

In an attempt to save the plant I trimmed all of the dead matter as deep as I could. From what I’ve read back then removing the dead parts would allow the energy of the plant to go into creating new shoots.

And new shoots it created.

After some time my Peace Lily was back on track but there was one noticeable difference.

Before the accident, the new shoots were trying to grow horizontally. After the deep trim, everything stayed short and tried to spread laterally.

Naturally, I followed my own experience and experimented with dwarf hairgrass in my initial trials with it.

It turns out that the little trick of trimming deep worked like a charm.

I recommend using this trick if the carpet does not want to spread, despite you doing everything else seemingly correct.

For a deep trim – cut your dwarf hairgrass to less than an inch or even lower if possible to do so without uprooting it.

Growing it in a sand-only substrate

So you have an established tank with a sand bottom and you’d like to spare your fish and shrimp the stress of installing a whole new substrate layer?

Good. It’s absolutely doable:

Since dwarf hairgrass leans on the root feeder side of the aquatic plants you’d still want to supply it with nutrients from your substrate.

Buy root tabs and spread them around in your aquarium sand.

Make sure that the sand layer is at least 2 inches deep, before the planting.

It won’t be redundant of you to use fertilizers in the water column as well. The more the better.

This is the exact way I’ve grown it in my aquarium setups, by the way. I have been using pure black sand for most of my tanks.

A practical dwarf hairgrass hack: Don’t place the root tabs directly underneath the patches of grass. Bury them in the sand between the separated patches. This way you’ll encourage the runners to spread even faster, as they’ll grow towards the source of nutrients.

Growing Dwarf hairgrass in a coarse gravel substrate

You can grow dwarf hairgrass in a coarse substrate such as gravel, but there are a couple of things to consider:

The hairgrass will have a slightly harder time forming a carpet in gravel, as its runners won’t spread as easily as they would in the sand. You’d need to supply it with root tabs at the least in order to achieve a lush lawn-like appearance.

That being said, you’ll also have a harder time planting your DHG.

Plant tweezers are a must here because otherwise, the grass blades will have a tendency to escape the gravel easily.

If you have bottom-feeders that like to uproot fragile plants you’ll probably need to cover the plant with a protective net.

Dry-starting Tips

You can use the dry start method when you grow your dwarf hairgrass, but it comes with its pros and cons:

The grass will grow faster emersed and it will form a carpet real quick.

If done right, you can expect a carpet by your third week.

Plant your dwarf hairgrass as described above to encourage the growth of its root runners even more.

Make sure that you leave some kind of ventilation (a hole in your plastic) or you’ll induce the appearance of mold or even rot.

The con of the dry starting is that whenever the plant has been grown emersed you will inevitably lose some of it when you fill your fish tank with water.

The melting and yellowing will happen just days after the plant goes submerged.

To encourage new underwater shoots you’ll need to trim.

This somewhat balances out the quick growth you’ll achieve when the grass is emersed.

Growing dwarf grass from seeds usually takes a couple of weeks longer.

That’s not recommended if you’re eager to start your aquarium carpet sooner.

Can you buy Dwarf Hairgrass from your couch?

And more importantly – will it be safely delivered when purchased online?

If you like the comfort of online shopping I will save you the time for research and point you in the right direction:

I am personally pleased with this Amazon seller.

They go the extra mile and really emphasize delivering the plant alive and healthy. It comes in a protective gel that keeps the hairgrass hydrated during the trip.

Note that they grow it emerged and you’ll see some yellowing at first, but as I mentioned above – trim and you’ll be alright.

Killing it

If you follow the above advice I can guarantee that you won’t end up as the owner of a perishing dwarf hairgrass plant.

I’ve seen quite a few fail to keep theirs alive, but from my experience, it’s all about being well informed beforehand.

This aquatic plant is the perfect candidate for a super attractive aquascape and the possibilities of one are endless.

Your imagination is the limit, literally.

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22 thoughts on “🌱Dwarf Hairgrass Care Guide (Grow a FULL Carpet in 4 Weeks)”

  1. Hi Mom. Thank you for this very complete explanation of how to plant the DHG. I just got some from a grower in Florida and can’t wait to plant. Being a new aquarist, I am learning as I go along–including killing fish with my first set-up. What a downer that was! Since I am new at this, I don’t have a lot of the implements that I should. I used a pair of chopsticks to plant the grass. But if I am planting the grass in gravel, should I go out and buy root tabs? I currently use Seachem Flourish liquid and that seems good–but will that be enough to encourage root growth or do I need the tabs?
    With the isolation from “the current situation”, I find the tank and its maintenance is very fun. But I find also I tend to spend a lot of money on it. Trying to not get a bunch of stuff I may not use. Thank you for any help you can give.
    Mary Ann

    • Hi Mary Ann,

      I think we’ve all been there when learning the aquarium hobby… so don’t worry about it. The pet fish stores should inform people better, it’s not the people’s fault they expect pet store staff to know more! Anyway, this is a rant for another time.

      Onto your question:

      I would say that with the root tabs you’ll see better results, especially when planting dwarf hairgrass in gravel substrate. I think the success behind my strategy is half root tab positioning, half keeping the hairgrass patches thin. Once the carpet is established you can just dose liquid fertilizers.

      I hope this helps and also thank you for being a reader. Ask away if you have more questions 🙂

  2. Once a carpet is established, how short can you cut it back to? Would an inch be okay in the long term?

    • Hi,

      It should be fine. Go for it.

  3. Hi, would ADA aquasoil capped with sand work well for substrate?

    • Hi Evan,

      Yes, that’s a classic setup. Make sure the sand is inert, and fill the aquarium slowly to avoid as much clouding as possible.

      Good luck!

  4. hai… i suggest to not trim the root… plant it with root buck out the soil… they need breath in adaptation mode…

    believe me… trim the root and trim the sword immediately its horrible for them… and you will carpeting for many years…

    • Hi Cristian,

      thanks for sharing your experience!

      Mine shows just the opposite though. 🙂

  5. Hi! I consider myself to be an intermediate aquarist, and I started out with an aponogeton ulvaceus and an amazon sword plant in my tall 10 gallon community aquarium, and after about a year they have taken off! The aponogeton is full and nearly 14 inches tall, and the amazon sword is very thick and lush at about 6 inches or so. I recently purchased miniature dwarf grass at my local Petsmart in hopes of developing that lush green carpet, and I had gotten nowhere. I realize that is because I had not seen this post! I planted them in their clumps, and being that I have a gravel substrate, it was not growing any bigger than when I had bought it. I planted them around the perimeter of my tank, about an inch apart with about 6-8 blades per “clump” (because I do not have tweezers, I used my fingers, which took about an hour or so). I have a strong LED light source, and I provide liquid Seachem Flourish once a week. What would you sugguest the next step to be in my process? I realize it will take a long time for the carpet to thicken, time is not a problem. I just want to do this the right way to get the best results.

    • Hi,

      Thanks so much for sharing your experience!

      Though I don’t think that’s necessary, a potential fix I see in your case would be to plant the clumps evenly over the area you want to be covered instead of just the perimeter. This way you could stick a root tab in-between 4 separate clumps of grass and stimulate their roots to grow towards the tab (as a source of nutrients).

      This way of planting would work best even without the root tab though slower. If you don’t want to rearrange (which I’d totally understand) just monitor and trim when the time comes (read, first signs of yellowing, or growing over 2 inches).

      You seem to have taken care of everything else like light etc. Just mind that Seachem Flourish supplies mainly micronutrients.

      Hope this helps!

  6. Thank you for this guide. I had split the plant I bought, but not nearly enough and didn’t think to do any trimming of the blades or roots. After about a week, I’d seen no new growth. After reading this last night I pulled out all my DHG, trimmed, split, and replanted it. Looking forward to seeing some faster growth!

    • The devil is in the details!

      Keep me posted with your progress, Julián.

  7. I’ve recently planted a bunch of hairgrass in my new self-sustaining tank, and they’ve been in it for maybe a week now. They’re barely an inch, should I trim it now to “encourage” growth?

    • Hi,

      Yes, you could do a slight trim. Are they showing signs of yellowing and wilt?

      • Only a few blades in each little patch. Should I remove them?

        • Yes, and it is a really good sign that you should trim the rest. 🙂

          Hope this helps.

          • Thanks for the help! I’ve trimmed them and now I’ve got my first extra sprouts out of each patch, maybe half an inch or so from each little patch. Glad to see it worked, even if a little bit.

          • Congratulations! Your dwarf hairgrass carpet is on its way now 🙂

            Out of curiosity – what lighting are you using and how deep is your tank without the substrate?

            I have an LED lighting for a planted tank guide, and if it’s not one of the models, I might consider adding yours.

            Cheers!

  8. Question about when to trim, just planted probably in thicker bunches than your recommendation, but the current plant length is above 2 inches possibly 3 on some.

    I am looking for both a lower carpet in open areas and higher grasses along my driftwood, what do you say, should I trim right away to ensure the heavier carpet in some areas? Is there any acclimatization period I should be aware of?

    • Thanks for commenting, Aaron,

      Based on the info you provided – you can trim immediately, yes.

      You will see yellowing in less than a week if the grass was grown emersed (which is usually the case).

      Keep trimming it back to 1.5 – 2 inches until the carpet establishes, and then leave it to grow to the desired height in the preferred locations.

      Hope this helps 🙂

      • Yeah that is great advice! The concern I had was whether trimming too soon would significantly harm the plant and it doesn’t seem like that will be the case. I am not sure if they were grown emersed or not..
        Thanks!

  9. Hi. Could you please give some information about growing from the seeds? Thanks

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