# Crinum Thaianum (Onion plant)



## Fry Lover (Feb 20, 2008)

I have about 12 of these that have been thriving in my community planted tank (48x18x24) for over a year now. Some of them reach up to 6 foot from bulb to tip if i dont prune them enough.

*I am wanting to experiment with a few of them in my 48x20x24 Malawi (mostly mbuna set-up).*

The biggest issue i think will be substrate or *lack of*. I only have about a 1cm sand depth (if that) at the back of my Malawi set-up, as things stand the Crinum Thaianum would be lodged behind some ocean rock and* it's roots would be almost completely out of the sand*

I know Onion Plants are very hardy (i've never had a dead one or dying one anyway), but is planting with virtually no substrate a non-starter?

Obviously i can do it and see what happens, just wondered what peeps views are?

Thanks


----------



## customdrumfinishes (Apr 1, 2008)

you can grow that plant with no substrate so it should be fine!


----------



## Fry Lover (Feb 20, 2008)

thanks that's what i was hoping


----------



## Robert Hudson (Feb 5, 2004)

> you can grow that plant with no substrate so it should be fine!


What makes you say that? This plant is a root feeder, and grows a massive, complex root structure. The roots have to have something to cling to, and without a deep substrate root growth will be limited, and at the least limit the growth of the plant. Now I have never tried to grow the plant with the roots suspended in the water so I don 't know what will happen for sure, but I do know when the bulb is floating in water it does not do well at all and will not sprout roots. The plant has to feed from something. In the substrate dissolved organic material accumalates and provides a nitrogen and mineral source for the plant. Without that it will be solely dependent on whats in the water.


----------



## travis (Oct 5, 2004)

My experience with _Crinum spp._ leads me to agree with Robert. _Crinum_ develop large root systems and do not do well floating. I have not tried growing them epiphytically so I can't comment there but I can say that, in my experience, they only thrive when well-rooted. You should try growing them in your sand substrate using something to hold them down. _Crinum_ will send roots down into your sand, although I doubt even a massive root system will be enough to hold them down in such a thin substrate layer, so weights will likely be necessary. You could also plant them in pots of sand/substrate and they should do just fine.


----------



## Fry Lover (Feb 20, 2008)

Thanks guys

I've decided to put just the one Onion Plant in my Malawi tank and it's bulb is currently being held in place in-between some lava rock with the roots virtually dangling in-between. I guess we'll see how it gets on.

I'll check on the appearance of the bulb and roots from time to time, as well as the obvious checking of the leaves. If it looks like it's going down hill i will move it back to my community planted tank.


----------

