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Next carnivorous plant dispatch date: 28th October
Next carnivorous plant dispatch date: 28th October
Ceratophyllum demersum (Hornwort)
Ceratophyllum demersum (Hornwort)

Ceratophyllum demersum (Hornwort)

Availability:
in stock, ready to be shipped
Availability:
in stock, ready to be shipped
Availability:
in stock, ready to be shipped
Availability:
in stock, ready to be shipped
Availability:
in stock, ready to be shipped
Availability:
in stock, ready to be shipped
Availability:
in stock, ready to be shipped
£0.00 - £0.00
£0.00
£3.00
£3.00 - £125.00
£3.00
Number of Bunches: 1 Bunch
Size Information

You can choose plants in various pot sizes. Non-potted plants arrive bare root for you to pot in the specified pot size.

Seasonal Information

Depending on the time of year, pond plants may be supplied fully-leaved, with flowers, or with foliage trimmed back.

Delivery Information

This plant is grown in the UK and sent directly from our tried, tested and trusted plant partner. Delivery price calculated at checkout.

Description of Ceratophyllum demersum (Hornwort)

Ceratophyllum demersum, commonly known as Hornwort, is a fully submerged aquatic plant used to maintain clean and balanced ponds. It grows naturally in lakes, ponds, and slow rivers across the UK and Europe. If you want clear water and a stable pond, this plant is a practical choice.

This species forms soft, bushy growth made of fine, forked leaves arranged in whorls along the stem. The leaves become more crowded near the growing tips, which gives a dense, feathery look. The plant floats freely below the surface and does not need planting in soil.

Its flowers are small and appear in the leaf axils during summer. Most pond keepers focus on the plant’s function rather than its appearance. It grows fast and absorbs excess nutrients that would otherwise feed algae.

You may also find Ceratophyllum demersum sold under these names:

  • Cedar moss
  • Coon tail
  • Fish blankets
  • Horn weed
  • Morass weed
  • Rigid hornwort
  • Cyrnddail

Think about your pond water. Does it turn green in warm weather? Hornwort helps limit this by competing with algae. It also releases oxygen during the day, which supports fish and beneficial bacteria.

Why add Ceratophyllum demersum to your pond?

  • Hardy and reliable in UK climates
  • One of the best oxygenating pond plants
  • Improves water clarity and balance
  • Provides shelter for fish, fry, and amphibians
  • Creates breeding areas for wildlife
  • Reduces algae growth by absorbing nutrients

This plant also offers shade below the water surface. This helps keep temperatures stable during hot spells. Dense growth protects fish from predators and strong sunlight.

Planting and care tips

  • Simply place stems in the water and allow them to float
  • Works in depths from 30 cm to over 1 m
  • Suitable for new and established ponds
  • Thin regularly to prevent overcrowding
  • Best introduced in spring or early summer
  • Can be weighted if you want it to stay in one area

You can combine Hornwort with native floating and marginal plants to create a balanced pond. It pairs well with species such as Callitriche, Potamogeton, and Myriophyllum. Mixing growth habits supports more wildlife and improves resilience.

If you want an easy, low-maintenance oxygenator that works in many pond sizes, Ceratophyllum demersum is a dependable option. It grows quickly, adapts to different water conditions, and helps keep your pond healthy throughout the year.

FAQs

What are the best oxygenating plants for a wildlife pond?

Good choices include submerged species such as hornwort, water starwort, water violet, water crowfoot and suitable pondweeds. The best choice depends on the pond's depth, size and conditions, so using more than one suitable species can provide useful underwater habitat as well as plant diversity.

How many oxygenating plants do I need in my pond?

As a general guide, the RHS suggests around four to five bunches of submerged oxygenators, each containing three to four stems, per square metre of water surface. Avoid excessive planting, as submerged plants also respire at night and overcrowding can cause problems.

Do oxygenating pond plants keep water clear?

Oxygenating plants can contribute to a balanced pond and compete for nutrients that might otherwise support excessive algae growth. However, they are not a guaranteed cure for green water, as water clarity is affected by factors including sunlight, nutrients, plant coverage and the overall balance of the pond.

Do oxygenating plants need to be planted in baskets?

It depends on the species. Some submerged oxygenators are rooted and can be planted or anchored in aquatic baskets, while others can grow freely in the water. Follow the planting instructions for the individual species rather than treating all oxygenators in the same way.

Do I need oxygenating plants if I have a pond pump?

A pump can circulate and aerate water, but oxygenating plants provide additional benefits such as underwater cover and habitat for pond life. For a wildlife pond, plants are therefore useful for more than simply adding oxygen to the water.

What are the best pond plants for a wildlife pond?

The best wildlife pond plants provide a mixture of underwater cover, surface shade, flowering habitat and places for aquatic insects to emerge. A balanced pond can include oxygenating plants, marginal plants and floating-leaved plants such as water lilies. Native species are particularly useful for supporting UK pond wildlife.

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  • 3 stars: 1 (50%)
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A
Anonymous
1 Bunch

Plant was good enough quality but arrived covered in duckweed. I now have to quarantine the plant for a few weeks before I can add to my pond setup. Bit disappointing

Thank you for taking the time to leave a review. I'm glad the hornwort arrived in good condition, but I do apologise about the duckweed. It should have been removed before posting to you, especially in hornwort where it can easily get trapped

A
Anonymous
10 Bunches

Excellent response time and service

Thank you - I appreciate you giving us the opportunity to make things right

Rated Excellent