Hornwort Pond Plant - Care & Grow Guide
by Tory Jon | Last Updated: November 16, 2022
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Hornwort, also known as coon’s tail, is a plant that originated in North America, but nowadays, it can be found all over the world. It features long stems covered with thin needles, resembling a raccoon's tail, from which it derives its nickname.
One of the best things about this plant is that it can thrive under almost any conditions, from tropical to polluted waters, full sun to full shade, and it's especially hardy even in cold temperatures.
Hornwort not only helps oxygenate pond water, but it also helps kill algae by releasing special chemicals using a process called plant allelopathy.
Invasive Potential: Low. Hornwort in pond and aquarium trade is typically Ceratophyllum demersum, also called coontail. It is widely distributed, but local rules and native status still vary, so do not release it outside a contained pond.
This plant does not have true roots. Grow it floating, tucked loosely under a rock, or lightly weighted; burying stems deeply in substrate is not necessary and can cause decay. Use USDA aquatic invasive plant guidance as a starting point and confirm current requirements with your state agriculture or natural resources agency. Never release unwanted pond plants, roots, seeds, rhizomes, or trimmings into lakes, rivers, streams, wetlands, drainage ditches, storm drains, or natural ponds.
Scientific Name
Ceratophyllum demersum
Invasive Potential
Low
Common Names
Coontail (or coon's tail) and rigid hornwort
Plant Type
Submerged pond plant
Light Requirements
Full sun to Full Shade
Hardiness Zones
USDA Zone 5 - 11
Bloom
Early June through late August
Grow Up To
10 ft.
Flower Color
Dark green to brown
How to Plant Hornwort in a Pond
Hornwort does not have true roots, so you do not need to bury it in aquatic soil. The easiest method is to float bunches on the pond surface or place them where they can drift among other submerged plants.
If you want a tidier look, loosely weight the bunch or tuck stems under a smooth rock without burying the stem tips. Avoid pushing hornwort deeply into substrate, since buried stems may decay before new growth can adjust.
For best results, thin dense growth regularly and remove loose needles or broken pieces from filters and skimmers.
Hornwort Care Guide
Hornwort is fairly low maintenance and only requires regular trimming to keep it at your desired size. Be sure to remove and properly discard any clippings away from the water, so they don't unintentionally spread and grow throughout your pond.
Keep in mind, Hornwort may lose needles during the first couple of weeks after planting, so you may need to remove the debris from your pond or clean your filter a little more often. Luckily, if you have pond fish, they may help keep your pond clean during this period by eating the plant droppings.
To overwinter Hornwort in colder climates, you can take the plants indoors and allow them to grow in an aquarium or tub (ensure they get ample light). Or simply allow them to die off and replant in Spring.
Responsible Disposal
Never release hornwort plants, roots, seeds, rhizomes, or trimmings into lakes, rivers, streams, wetlands, drainage ditches, storm drains, or natural ponds. Do not dump pond or aquarium water containing plant fragments into natural waterways.
Hornwort spreads easily as stem pieces. Remove floating clippings with a net, dry and bag them, and never flush or rinse fragments into streams, storm drains, or natural ponds.
Hornwort Care Card
Download our free printable care card for the Hornwort plant! Click the care card below and save the PDF file to your computer. You can easily print off the 3x5 care card or access it right from your phone. Get all the important information you need to keep your Hornwort plants healthy and happy!
Plus, we provide a blank card for you to print and fill out yourself. Print it as many times as you like to create cards for all your plants!
Pond Plant Care Card Set
Get the full printable set of 23 pond plant care cards in one PDF. The cards are formatted for quick reference on your phone or easy 3x5 printing.
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