Hornwort is a popular aquatic plant for both fish tanks and outdoor ponds because of its fluffy-looking stems, extremely fast growth, and ability to consume excess nutrients from the water. Learn about the care requirements for hornwort and whether or not it’s the right plant for you.
Ceratophyllum demersum is known by many common names, such as rigid hornwort, hornwart (a frequent misspelling), and coontail. It grows very tall in the wild and will easily reach all the way to the top of your aquarium or pond. Normally hornwort is found floating at the water surface, but when planted in the substrate, it looks like a fluffy underwater bush with many long branches or side stems. The bright green leaves are thin and rigid, similar to pine needles. Much like water sprite and java moss, hornwort has dense foliage that provides excellent protection for baby fish and shrimp.
Where is hornwort found? Hornwort can survive in a diverse variety of climates and is found on every continent except for Antarctica. It prefers to grow in still or slow-moving bodies of fresh water that contain lots of organic nutrients in the water column.
Does hornwort clean water? Fast-growing plants like hornwort are good at “cleaning” aquarium water because they consume waste compounds from the water (e.g., ammonia, nitrates, and phosphates produced by fish waste and excess fish food) and use it to grow more leaves. With enough light and nutrients, hornwort can easily grow 1-4 inches (3-10 cm) per week.
Do snails eat hornwort? Aquarium snails are detritivores and do not eat healthy plants but rather dying leaves and other organic debris. If you see a pest snail eating a plant, most likely the plant has some unhealthy leaves that the snail is cleaning up for you.
Do goldfish eat hornwort? In general, plant-eating animals (such as goldfish, koi, African cichlids, and turtles) do not eat hornwort. Possible reasons could be the slightly serrated leaves, hard texture, or taste that makes it unpleasant as food.
Hornwort leaves are not completely smooth but have small bumps that give it a slightly spiky texture.
Hornwort is a popular aquatic plant known for its delicate, feather-like foliage. With its ability to grow rapidly and tolerate a wide range of conditions, hornwort is an excellent choice for adding greenery and oxygenation to ponds. If you’re looking to incorporate this attractive plant into your pond, follow this simple step-by-step guide.
Why Add Hornwort to Your Pond?
Before jumping into planting, let’s first go over why hornwort makes a great pond plant:
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Oxygenation – Hornwort releases oxygen into the water through its leaves, helping keep pond fish and other aquatic life healthy.
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Nutrient absorption – This fast grower readily absorbs nutrients like nitrogen and phosphorus helping prevent algae blooms.
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Shelter – Its dense, branching structure provides shade and hiding spots for fish.
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Hardiness – Hornwort can tolerate a wide temperature range from 50-85°F and does well in sun or shade.
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Visual appeal – Its delicate, bright green needles swaying underwater create beautiful pond aesthetics.
Step 1: Choose a Location
When selecting where to plant your hornwort, aim for a spot that receives full sun to partial sunlight. While it can tolerate some shade, more light will maximize growth.
Ideally, plant hornwort around the edges of your pond in areas that get sunlight for much of the day. Avoid planting it directly under trees or structures that heavily shade the pond.
Step 2: Prepare the Planting Area
Once you’ve identified the planting spot, prepare the area by:
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Removing any weeds, leaves, or debris from the bottom surface.
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Adding a 2-3 inch layer of sand or fine gravel if the bottom is mucky. This gives the roots something to anchor in.
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Filling the pond back up with fresh water if needed. The planting area should be fully submerged in 12-24 inches of water.
Step 3: Plant the Hornwort
To plant each hornwort stem, follow this simple process:
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Anchor the main stem to the prepared pond bottom using a rock or other heavy object on top of the roots. This prevents it from uprooting or floating away.
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Alternatively, you can bury part of the lower stem directly in the substrate. Ensure 2-3 inches are covered by sand/gravel.
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Plant stems every 6-12 inches apart to allow ample room for growth.
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Cut away any dead or diseased portions of the plant using sterilized scissors before planting.
Step 4: Maintain Optimal Growing Conditions
Once your hornwort is happily planted, be sure to provide optimal growing conditions:
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Sunlight – Ensure the pond gets at least 5-6 hours of direct sun daily. More is better.
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Nutrients – Apply specialized aquatic plant fertilizer every 2-4 weeks during the growing season. This fuels rapid growth.
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Water Flow – Position the hornwort away from areas of high water turbulence. The slender stems prefer minimal water motion.
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Pruning – Trim back overgrown stems as needed to control size and shape. Removing 30% at once is safe.
Troubleshooting Common Hornwort Issues
If your hornwort starts turning brown, shedding needles or growing poorly, look out for these common problems:
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Insufficient sunlight – Hornwort needs lots of light. Increase sunlight exposure.
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Low nutrients – Add more frequent doses of aquatic plant fertilizer.
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Invasive algae – Manually remove algae growing on the hornwort.
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High water flow – Reposition away from areas of high turbulence.
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Cold temperatures – Growth may slow substantially in water under 50°F.
With the proper care, hornwort can thrive for years in backyard ponds. Its delicate foliage and oxygenating effects make it a great plant for pond health and beauty. Follow this guide to get your hornwort successfully established. Soon you’ll have lush, rapidly growing stands purifying and beautifying your pond.
How to Propagate Hornwort
In the wild, hornwort can form little buds that drop to the ground during the cold season and sprout when the weather warms out. At home, the most common method of propagation is to cut off a side shoot or trim off the top of a tall stem. Any segment of hornwort will quickly become a new plant if you let it float at the surface or plant it in the ground. In fact, one of the easiest ways to get hornwort is to ask around and see if any local hobbyists have some extra trimmings to give away, which they are usually more than happy to share. We do not sell hornwort because it doesnt survive in shipping very well, but we have a whole collection of our favorite beginner plants for you to browse.
How to Care for Hornwort
This aquatic plant can live in a huge temperature range from around 50-85°F (10-30°C), so you can put it in tropical aquariums, cold water tanks with no heater, and outdoor ponds (where they can often survive the winter season depending on your climate). Hornwort grows best as a floating plant, where it has greater access to light and carbon dioxide from the air. Some people like to plant it into the substrate or attach it to hardscape, but because it never grows proper roots, the attached end tends to rot away. Make sure to prune back your hornwort if it starts growing out of control so that it won’t block out the light if you have other plants or limit gas exchange at the surface if you’re keeping fish.
Hornwort tends to prefer gentle flow, so make sure the needles don’t accidentally get sucked up by your filter intake. It can grow under low to high light and does not require carbon dioxide (CO2) injection. Because it grows so quickly, it’s best to use it as a background plant in larger tanks (unless you have the time to constantly trim it). In addition, the fast growth rate means it will quickly drain your aquarium of all nutrients, so you may need to regularly dose Easy Green liquid fertilizer in the water column to ensure that the other plants get enough to eat.
Why is my hornwort shedding its leaves? Hornwort sheds needles anytime there’s a major change in water parameters or it’s kept in an unfavorable environment, such as strong currents, not enough light (especially at the base of planted stems), lack of nutrients, or dosing of certain chemicals like liquid carbon. The most common occurrence is when you first add it to your tank and the plant is not used to your water conditions. Don’t throw away the whole plant, but instead wait for it to recover and it will quickly begin growing new leaves and shoots. Also, make sure to gravel vacuum the fallen leaves to prevent excess nutrients from building up in the aquarium.
Hornwort is easily propagated by trimming off a section and floating it in a new fish tank.
Beginner Care: Hornwort Plant Guide
FAQ
How do you put hornwort in a pond?
Growing Instructions: Hornwort is a free-floating plant that requires no planting or substrate. Simply pop it into the water, and it will naturally find its own level, floating or sinking depending on the conditions. Hornwort thrives in still or slow-moving water and can grow at depths up to 1.5m.
Should hornwort float or be planted?
Hornwort doesn’t grow roots, so it’s best kept floating or attached to a weight. You can stick the ends in a pot of rockwool, that works extremely well for keeping it contained.
What are the disadvantages of hornwort?
Hornwort is an invasive freshwater weed that threatens most underwater plant communities, negatively affecting the environment and recreational values. It rapidly invades water with all different levels of clarity, temperature, light and nutrient level. Its thick growth crowds out native species, and blocks waterways.
How to properly plant hornwort?
If you wish to reproduce Hornworts in a tank, you should cut the stems and leave them floating on the water’s surface. Routine stem trimming can help with propagation and eventually grow and evolve into a new hornwort. As for how and where to cut it, it makes no difference, and you can cut it into two or three pieces.