Eleocharis Parvula Care (Dwarf Spikerush)

Eleocharis parvula

Eleocharis parvula, also known as dwarf spikerush or dwarf hairgrass carpet, is an ideal low-maintenance lawn alternative for homeowners with mild winters and warm summer climates, such as that of the southern United States. It’s one of the few hardy species of grass that won’t wither in hot summers, but it will easily die if exposed to frost or frozen soil over the winter months.

Eleocharis parvula can be an attractive and functional addition to the right landscape, but it’s extremely sensitive to environmental factors and will only thrive in very specific conditions.

The dwarf spikerush is one of the most popular carpeting plants that aquarists use in their aquariums, thanks to its lush green color and easy maintenance requirements. This dwarf hairgrass carpet plant has smaller leaves than some other species of Eleocharis and isn’t quite as tall, but it does well when used in combination with other short-growing plants to create a carpet-like effect in your aquarium or pond bottom.

Eleocharis parvula is a small evergreen perennial grass native to the southeastern United States and eastern Asia. It thrives in low-fertility soils and prefers to be kept damp, making it an ideal addition to any aquarium planted with aquatic plants. If kept in water between 23°C and 28°C, this plant can grow up to 10 cm (4 in) tall and spread out to form a dwarf hairgrass carpet of 8–10 cm (3–4 in).

The following care guide will help you create an ideal environment in which your dwarf spikerush can thrive and grow.

Origin and descriptions

Eleocharis parvula

Eleocharis parvula is a species of flowering plant in the sedges family, Cyperaceae. Common names include dwarf hairgrass carpet, dwarf spikerush, or small spike-rush. This aquatic plant is native to North America from Texas to Florida, south to Costa Rica, and also in West Africa. It can be found in several different types of freshwater habitats such as swamps, riversides, and ditches. In central Mexico, it is common along shorelines.

It prefers full sun but tolerates partial shade as well. In addition, it requires moist soil that stays between 73 and 83 degrees Fahrenheit (23-28 degrees Celsius). Watering should occur after the first two weeks of growth to keep adequate moisture levels for optimal growth.  Although there are some species variations, Eleocharis parvula usually reproduces via rhizomes rather than seeds.

Rhizomes are used for survival during dry times. Because of their ability to reproduce vegetatively through rhizomes, they do not require sexual reproduction to spread their genetic information and produce offspring.

In tropical regions where temperatures are consistently high enough over an extended period of time, however, Eleocharis parvula is capable of reproducing sexually via seed production.

Species profile

Eleocharis parvula

Eleocharis parvula is a miniature bog plant that forms a carpet of dense, textured foliage. If grown in conditions with adequate moisture, dwarf hairgrass carpet can spread quickly to cover large areas. This species is typically submerged year-round in natural settings but can be grown as an above-water annually if given consistent water attention.

Dwarf spikerush has nearly flat green leaves that are about 1 inch long and grow up from tiny rhizomes clustered just below surface level. In optimal conditions, Eleocharis parvula will flower from May through July with inconspicuous flowers atop tall slender stems.

Eleocharis parvula height

Eleocharis parvula is a small, clumping grass that can reach heights of up to 4 inches (10 cm). It spreads via rhizomes, so it will slowly grow bigger over time. However, you can keep it in a smaller size by regularly trimming it back. It doesn’t grow upright like most other ornamental grasses; instead, its stems lie horizontally across the water surface.

How do you grow eleocharis Parvula?

Eleocharis parvula

Reproduction (propagation) in Eleocharis parvula can be categorized into two different types: sexual reproduction through seed production and vegetative reproduction through rhizome propagation.

Unlike most plants that must be rooted in the substrate, eleocharis will grow well as a free-floating plant in your aquarium. Just drop it in and don’t worry about it! It grows extremely quickly so if you have a small tank or are just getting started there isn’t any need to buy multiple plants.

Because of its preference for standing water, parvula can reproduce quickly from both rhizomes (underground stems) and seeds. Although care of all species of Eleocharis is generally similar, propagating eleocharis parvula may pose some challenges if you want to multiply your plants through seeds as opposed to rhizomes.

Fortunately, there are a few steps you can take to ensure the successful germination of your seeds.

  • First, only collect mature specimens for seed harvesting, these will be fully developed and ready to produce viable offspring.
  • Then, plant your seeds in moist soil in late fall or early winter—the preferred period for seed production—and let them remain there until spring when they should begin germinating naturally on their own.
  • Be sure not to disturb or remove your germinated seeds before flowering occurs, as doing so will likely render your plants sterile.

Note that it’s much easier to propagate eleocharis parvula using rhizomes rather than seeds. All you have to do is dig up and divide your older clumps every couple of years, replanting several sections of each clump during each division. Simply treat each section with rooting hormone after planting, and then keep an eye out for sprouts beginning about three months later.

Eleocharis Parvula care

Eleocharis parvula

Eleocharis parvula is a popular species for aquariums because of its dwarf growth habit and vibrant red stems. Dwarf hairgrass carpets look amazing when planted densely in aquariums that don’t contain strong light or extra CO2. Due to their size, Eleocharis Parvula can be difficult to remove from filter intakes, so plan your aquascape accordingly.

Eleocharis parvula is not a picky plant; it will grow in a wide variety of different substrate/soil combinations. The only two requirements that must be met are:

  1. Sufficient light, which can be achieved through frequent water changes or planting it in a well-lit area, and
  2. Good water quality, as Eleocharis parvula is highly sensitive to toxins/toxins found in tap water (hardness: soft to moderately hard; pH: 6.0–8.5). It does best when planted with other aquatics, especially Cryptocoryne species.

Light requirements

Eleocharis parvula is a terrestrial plant that grows in full to partial sun. It’s a good idea to give it plenty of indirect light and high humidity, which can be hard to come by in indoor environments.

If you’re trying to grow Eleocharis parvula indoors, make sure it gets enough natural light; fluorescent lighting isn’t sufficient for providing enough levels of illumination for dwarf spikerush growth.

It does best with a lot of sunlight, as long as it is filtered through leaves or other plants, rather than in direct sunlight that will burn its tender foliage.

The Dwarf Spikerush requires at least four hours of direct sunlight each day. This can be provided by placing it next to a large tank or aquarium where light can filter through water; however, if you are planning on keeping live plants in your aquarium, be sure not to over-plant your tank because they require ample lighting.

Substrate/soil requirements

Eleocharis parvula is a rhizomatous plant that grows best in highly oxygenated, fast-draining substrates such as sand or clay pellets. Its shallow roots mean that it requires much more water than other plants in order to thrive, so frequent watering is important if growing in sand or another loose substrate.

Some driftwood or rocks are also a good idea for Eleocharis parvula to grow over, as well as ensure its abundance of surface area for photosynthesis. An under-gravel filter is ideal for use with E. parvula, although sponge filters can work just as well (as long as they’re large enough).

CO2 supplementation may be necessary in order to increase plant growth rates; however, care should be taken not to disturb substrate chemistry too much when choosing equipment for CO2 injection (For example, don’t inject right into sand/substrate).

Fertilizer

When growing Eleocharis parvula, one of its biggest needs is phosphorus. It will also use a lot of nitrogen. Liquid fertilizer with a high phosphorus percentage works well when growing your plant. You can use something like bat guano or feather meal, but you’ll want to dilute them quite a bit before applying them directly to your plant. Alternatively, a higher NPK ratio fertilizer should work equally well. Be sure to not overfeed your plant, however; if it gets too much nitrogen, it may develop brown leaves.

Watering

One of Eleocharis parvula’s most attractive characteristics is its ability to adapt to a wide range of water conditions. It requires well-aerated, shallow water in which it can grow to maturity. While Eleocharis parvula does not require supplemental CO2 or other carbon sources, it will grow to at least twice as fast if provided with them. A good rule of thumb is that when growing any type of aquatic plant, adding more CO2 will make plants grow faster, regardless of species.

Temperature

Eleocharis parvula

While eleocharis parvula is cold-hardy, it will not thrive in temperatures below 50 degrees Fahrenheit (10 Celsius). It may take a bit of time for your plant to acclimate, so wait about one month after planting before you put it outside if you live in a region where lows drop below freezing.

Also, avoid drafts from air conditioners or fans. Adding some humidity with regular misting will also help keep your plant thriving.

Humidity

Dwarf spikerush does well in high-humidity environments. It does best when you give it a lot of water—but don’t let it sit in a small pool of water, or it will rot. Instead, use something like a stone or piece of driftwood to soak up excess water.

You may want to keep your eleocharis parvula indoors if you live somewhere cold with low humidity (below 50%). Indoors, keep it on a sunny windowsill. Otherwise, keeping an it outdoors is ideal.

An ideal humidity range is 60-70% (you can purchase a hygrometer to measure relative humidity at home). You’ll likely want to keep it humid during winter when low temperatures inhibit growth. In warmer weather, dwarf spikerush will do just fine with average indoor humidity levels. It will survive dryer months outdoors—and its leaves may curl—but it should bounce back in time for spring.

Pruning

To keep your dwarf spikerush looking full, regularly remove old leaves by pruning off at ground level with a sharp pair of scissors. Do not remove more than one-third of new growth each time you prune.  If your plant has gotten leggy (too thin), cut it back so that it sits only an inch or two above its base.

Your plant can be propagated simply by dividing rhizomes when they are dormant in winter (when frost is present). When dividing plants during dormancy, leave about an inch of stem on each piece to increase the odds that it will survive and flourish once planted.

Growth rate

Eleocharis parvula can be a slow-growing plant in proper conditions. It has been documented that it can take anywhere from a few weeks to several months for your plant to show signs of new growth under certain conditions.

Additionally, some sources indicate that Eleocharis parvula grows at an extremely slow rate if it does not receive ample amounts of light or CO2 supplementation. However, other resources note that when given ideal growing conditions (high levels of lighting and CO2 supplementation), Eleocharis parvula can grow quickly to cover all available space within two weeks’ time.

Toxicity

A common concern when working with aquatic plants is their potential to be toxic. In fact, some are so toxic that it is illegal to remove them from most water bodies. Eleocharis parvula, however, has been shown not to have any deleterious effects on wildlife or humans when used in home aquariums.

While no fish or amphibian species are threatened by Eleocharis parvula, owners should still exercise caution while moving pieces of the plant around within an aquarium and should refrain from eating any part of a plant if they decide to keep one as a pet. Additionally, extreme care should be taken to avoid spilling water containing any submerged parts of it onto other surfaces.

Pests and diseases

The most common problem for Eleocharis parvula is mealybugs, especially if it is grown in soil. Mealybugs will often infest potted plants, but can also move from one pot to another or one plant to another. Dwarf spikerush is a relatively tough plant and so can survive for some time with its leaves covered in mealybugs, but eventually, it will become too weakened by them to thrive.