Crinum thaianum

Alani Davis
Thu, 31 Jan 2013 18:22:07 PST
I have grown Crinum thaianum for about 20 years in aquaria and during the
summer in various ponds and water gardens. It will grown in fairly shallow
water water but really prefers some depth. My present aquarium is a
standard 75 gallon which is 18" deep x 18" x 48" and when the Crinum
thaianum is really happy this is barely big enough. This is mainly because
of the foliage which can easily get up to 9-12 ft long or more and makes a
substantial layer along the the surface of the tank as well as shading many
of the other plants quite a bit. I have had scapes form a couple times but
I have had trouble getting it to flower regularly and several times these
scapes have aborted mid development and not opened flowers. I have found it
tricky to keep it happily fed without upsetting the equilibrium of the tank
so I just enjoy it mainly for the foliage. I have had the bulbs get up to
about 3" in diameter but I understand they can get bigger. When mine have
gotten that big they usually produce so many offsets that they quickly
loose size. A healthy bulb can offset steadily and produce several in a
year if the conditions are good. I have had mixed result with growing them
in ponds and I think they prefer warmer water and perhaps benefit from some
water movement or slight current, but I have not had any better luck
flowering them in the sun. Indoors or out they like a lot of light. I grew
them successfully first under metal halide spotlights but after tiring of
small street light -like lights in the living room with the associated
annoying buzzing, excessive heat, and power bills, I have switched to a T5
HO florescent fixture with four bulbs. This seems to work fine but a deeper
tank say 30-36" would really show it off better and give it room to spread
out a little better. I have also been growing the African aquatic species
Crinum calamistratum and Crinum natans which have beautifully undulated
foliage and grow in the same conditions as Crinum thaianum. I understand
these two can get quite large as well in the wild but at least in the
aquarium they don't seem as long a foliage as C. thaianum (just 3-6 feet)
and seem to tolerate low light levels better. However they still have only
flowered for me when light levels were higher. While Crinum thaianum has a
globose bulb, the african species have a more stem like base much like
Crinum asiaticum. One problem with these plants if one successfully gets
them to flower is the light source itself. The scapes of course orient
toward the light source and to maximize the intensity of the light into the
water, the light source must be either extremely bright or close to the
water surface. So the trick is to catch the scape before it emerges and to
redirect and shield from the heat of the light as the buds develop or they
will wither to a crisp long before they open or as they open.

Alani Davis
Tallahassee, Florida

On Thu, Jan 31, 2013 at 8:11 PM, Eugene Zielinski <>wrote:

> I found that the dried bulbs available in pet stores do eventually sprout
> roots and leaves.  It just takes a while, like a month or so.
> I also found that C. thaianum does not have to grow completely submerged in
> water.  My bulb grew nicely in a pot of soil sitting in a saucer of water.
> Now I'm wondering how big the bulb has to be before it will bloom.
> Eugene Zielinski
> Rapid City, SD
> > [Original Message]
> > From: James Waddick <>
> > To: Pacific Bulb Society <>
> > Date: 1/31/2013 8:18:28 AM
> > Subject: [pbs] Crinum thaianum
> >
> > Dear PBSers,
> >
> >       Does anyone grow Crinum thaianum? It is not on the PBS wiki, but it
> seems very available at least here in Kansas City.
> >
> >       We have two big box pet stores selling dormant bulbs of this
> species in
> various packing for only $4  or less. It is marketed at suited to totally
> submerged aquarium growth. The IUCN calls it Endangered and says it comes
> from a very restricted range. Stores selling small dormant bulbs all say
> they come from Thailand.
> >
> >       Am I missing something? Even if commercially propagated how can
> Endangered Species be sold so freely and cheaply? I presume this is a world
> wide commerce.
> >
> >       Any ideas from the Crinum pros?                 Best
>  Jim W.
> > _______________________________________________
> > pbs mailing list
> >
> >
> >
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