Jump to content

February's Plants Of The Month Are.....


Recommended Posts

  • Regular Member

We have two really deserving plants to look at in February. I've tried both in my tanks before and both have been excellent.

Let us know what you think of them. :)

Here's the first: our old favourite, Hornwort.

Hornwort (Ceratophyllum demersum)

A favourite choice for coldwater aquariums, this charming plant is very decorative yet undemanding.

Its various names clearly reflect its distinctive appearance: the botanical name Ceratophyllum demersum literally means ?horned foliage under water?. The common term ?Hornwort? also reflects the leaf shapes ? which really do look like tiny sets of antlers growing up the stems ? combined with the Old English word ?wort?, meaning "plant?. In the US, it is often known as Coontail because the leafy rings are denser at the top.

In the aquarium, Hornwort looks wonderful clustered around ornaments such as bogwood or planted in little terracotta pots filled with gravel. Its height also makes it useful as an imposing background plant, but it is best in groups of 3-5 bunches, rather than as single specimens which can look a bit ?lost? and fragile.

A good oxygenator, it is also ideal for ponds where it eventually forms dense clusters, either completely submerged or floating. These watery forests make an ideal spawning ground or nursery for young fish.


Difficulty level: easy

Availability: commonly available in most fish stores and garden centres around the world

Cost: usually very inexpensive

Max height: 40 cm

Max width: individual stems usually approx 2cm across; plants forms large clumps with time

Growing speed: fast in bright light, slow or non-existent in low light.

Goldfish edibility rating: distasteful to most goldfish, although some piggy fish will nibble at it!


Light: prefers bright light but will tolerate low to medium light

Nutrients: no extra fertiliser needed, though a little liquid fertiliser will encourage growth

Temperature: 10-28C / 50-82F

pH tolerance: any, but prefers neutral to slightly alkaline conditions

Hardness tolerance: any, but prefers harder water

CO2: not required, although it will flourish if given extra CO2

Salinity: will not tolerate salt, so remove Hornwort if using salt treatments


Planting: Hornwort does not have roots so it derives no benefit from being planted in the substrate. However, it will not hurt it to do so since it can modify some lower leaves to act as its roots. Alternatively, it can be used very effectively as a floating plant.

Propagation: Couldn?t be easier! Simply break pieces off the stems. These pieces will become new plants.

Maintenance: Hornwort is brittle and breaks easily so some care must taken when cleaning round it in the tank. The leaves can sometimes trap floating debris but gently dabbing them with a small soft paintbrush cleans them effectively. Any dead leaves simply fall off and can be vacuumed up as part of a normal cleaning routine.

Ponds: Hornwort is a perennial plant so any die-back in the winter will be replaced by new growth in spring. Can grow very quickly if the pond receives a lot of sunlight but just pulling out bunches of it occasionally will keep it in check.


Link to comment
Share on other sites

  • Regular Member

And here's the second:

Bitter Cress / Cardamine (Cardamine lyrata)

A slightly more unusual aquatic plant, Cardamine - also known as Bitter Cress, Japanese Cress, Japanese Ivy or Chinese Ivy ? has its origins in oriental marshlands. Its trailing form gives it an attractively ?messy? appearance, making it ideal for tanks with a natural look.

Cardamine is easy to grow in summer ponds, but will not survive outside in winter. If left unchecked, its attractive heart-shaped leaves will creep out of the water and along the margins.

In the aquarium, the bright yellow-green colour of this plant is absolutely spectacular if placed against dark rocks or bogwood or sent twining through dark green plants. Again, it is best planted in groups rather than as single stems.

Relatively undemanding, Cardamine is a good choice for both beginners and experienced aquarists alike.


Difficulty level: fairly easy

Availability: often available in most fish stores and garden centres round the world

Cost: usually inexpensive

Max height: 50 cm

Max width: 30 cm

Growing speed: fast in bright light, slow in medium light.

Goldfish edibility rating: not known, but apart from an initial exploratory nibble my goldies did not eat it!


Light: prefers bright light but will tolerate medium to bright light

Nutrients: a little liquid fertiliser will help growth

Temperature: 18-25C / 64-77F Cardamine will die if exposed to prolonged higher temperatures.

pH tolerance: 6-8, prefers neutral water

Hardness tolerance: any

CO2: not required, but will grow much faster and stronger with added CO2

Salinity: will not tolerate salt, so remove if using salt treatments


Planting: plant directly into substrate in groups. Turbulent water will damage the plants so do not place close to a waterfall or strong filter return tube.

Propagation: cuttings rooted into a light substrate will take root easily

Maintenance: remove any occasional browned leaves, wipe off algae very gently with a sponge.

Ponds: Cardamine will not last through winter so either bring indoors or replace with new plants in the spring.


Link to comment
Share on other sites

  • Regular Member

I have the hornwort just floating around in the tubs outside all year round. It doesn't look too great in the Florida "winter", but it alway comes back full power! :wub:

Link to comment
Share on other sites

  • Regular Member

Great article, Emma! Very informative. :) Did you know that hornwort is actually becoming illegal in some of the western US? I heard that the state of Washington has banned it. Im sure California will be next as we seem to just ban anything and everything. Apparently the hornwort has been released to the wild and grows so quickly that it overtakes all the native vegetation and clogs waterways and stuff. Just a reminder, never ever throw anything from your aquarium into the wild!!

Link to comment
Share on other sites

  • Regular Member

Hee hee, yeah we Californians try to protect our natives. I believe it is very important to keep invasive organisms--plants, fish, birds etc. from overtaking the natural species and part of that duty is by not throwing them into the wild. I can think of some examples of introduced species that cause problems--

-European snail (no offense to the Europeans, only the snail has very few predators here and I'm not keen on trying escargot)

-Water hyacinth--clogs waterways, invades rice fields (but oh, such a pretty flower)

-Northern pike, a voracious predatory fish

Ecosystems can be slow to absorb new additions, especially additions that have some type of advantage over the native inhabitants.

emmahj: I have a 20 gallon tall tank. The lighting is a single fluorescent tube, 15 watts (18 inch light). The bulb is called Hagen "Power-Glo" and was recommended for planted tanks and for marine tanks with corals. I still have brown algae so I have some doubts as to how much light it is really providing...

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...