July '11 Plant Of The Month: Hemianthus Callitrichoides

[mellowvision]

Hemianthus callitrichoides
HC Cuba, Dwarf Baby Tears

Origin: Cuba
Family: Scrophulariaceae
Plant type: Creeping Stem Plant
Difficulty: Moderate
Growth rate: Fast
Tank Placement: Foreground

Lighting: Moderate to High
Water Conditions: 68-82° F, KH 0-10, pH 5.0-7.5
Requires: CO2 Fertilization, Substrate Fertilizer

One of the holy grails of the planted tank hobby, Hemianthus callitichoides is an iconic foreground plant, most often used to create low carpets of lush green growth. The smallest known aquatic stem plant, it is prized for it’s ability to rapidly cover the substrate with bright, tiny leaves. A native plant of Cuba, Hemianthus callitichoides, or ‘HC Cuba’ is an amphibious marginal plant that inhabits the muddy, shallow edges of brightly lit freshwater streams and ponds. Because of it’s amphibious nature, HC can be used fully submerged and in high humidity paludarium and vivarium environments where it has access to bright light.

In the planted aquarium HC Cuba can be a challenging plant for the beginner. While it is a rapid grower under bright lights, it can be susceptible to algae growth if not given adequate co2 and regimented fertilization. When it is lacking in light, it can yellow and become leggy, stretching for light instead of creating the desirable compact growth it is known for. Given ideal conditions, HC will spread rapidly and can climb driftwood and rock work, using short roots for attachment.

One of the most popular methods of HC cultivation is the dry start method, where the plant is grown emersed for the first few weeks and is then flooded. This allows the plant to spread roots quickly while drawing it’s co2 from the air, and gives it an advantage over algae which enjoy wetter conditions. The plant will grow faster and produce lower, more compact carpeting when its leaves are exposed to air. It will also grow rapidly if attached to cork bark or driftwood that positions the plant with it’s roots at the waterline, requiring no additional CO2, and very little additional fertilization. When grown attached to emersed hardscape, HC shows much faster growth when it’s roots receive a constant flow of water from a drip line or filter return, and the plant will climb across the hardscape towards the light.

In my experience, HC Cuba is a easy plant to deal with when grown above the waterline. It spreads beautifully and shows little demand for anything but humidity and light. Under water however, it becomes challenging to balance the high amounts of light and nutrients it demands without pressurized co2. Some may have luck with Excel or yeast driven co2, but I have found that fluctuating co2 levels are not appreciated by the plant, and put HC at a disadvantage to hair algae. If hair algae takes hold in HC, it can quickly become impossible to remove it from the tight tangle of runners. Submerged, I would only recommend the plant for those using pressurized co2 and regimented fertilization.


photos
HC growing in high light with yeast brewed CO2



HC beginning to creep across Eco Complete substrate



HC being cultivated on cork bark using water jets constantly spraying the roots



Planting HC on cork at the waterline in a paludarium

[Mgamer20o0]

half the month gone by and no posts. HC is one of the most popular foreground plants around. i personally havent done a lot with it though but when ever i get it in it sells so fast. i think i am going to try some like how mellow has it with the spray on the roots. great write up.

[247Plants]

I've murdered my fair share before catching it right. Excellent write up mellow!

[dundadundun]

excellent write-up and gorgeous pics.

[oo7genie]

I've tried dwarf baby tears a few times, but could never get it to grow in my planted tanks. Best I managed to do was keep it from dying. I think it has to do with the depth of my planted tanks, 60 & 90g. I just can't get enough light to reach the bottom without beefing things up out of my price range. But I've always wanted a nice carpet of it, and will definitely be using it if I ever set up a smaller planted tank someday, using the dry start method.

Great write up!

[mellowvision]

thanks peeps.

oo7genie - yeah, in a deep tank, you'd really need to blast it with light. Dry start is really the way to get it going, but you might consider using spotlights at mid day to just pump light to the HC, instead of lighting the whole tank, you'd probably have more luck keeping algae to a minimum if you just direct the light where you need it.

[lami408]

Barely planted these today