Pseudobulb without roots, Sweet Sugar - Orchid Board

Blueszz · #1 01-24-2009, 10:40 AM

4 weeks ago I repotted an Oncidium Sweet Sugar. The smallest pseudobulbs (back bulb?) came of per accident. It has 2 leaves (still green) but no roots at all.
I found on a forum that I could lay it a side (cooler, darker) in the hope dormant eyes would develop into new growth. That is what I did.
Once a week I gave the lower part of the pseudobulb a bath in a Superthrive solution.

I checked the pseudobulb today and indeed, a dormant eye came alive but is still tiny. The pseudobulb still looks firm and not too shriveled. It doesn't look much different from three ago.

I wonder what to do with it now.

- increasing light a bit?
- increasing humidity? (it will be 40% on average now)
- keeping temp lower than room temperature? Let's say 60F ?
- can I help rooting of the old pseudobulb with a rooting hormone like Superthrive (no KLN available here right now)?
- no live sphagnum moss available right now, but I do have beautiful dried NZ sphagnum moss.

I don't feel comfortable giving it a bed of sphagnum moss, I'm too afraid for rot in my climate (this time of the year). What about having it slightly above the moss. I thought of making it a mini green house from a soda bottle.

It's not that I'm desperate to save the pseudobulb and it's new growth (the original plant is very healthy and strong, with a lot of new growth) but it's a great learning opportunity in case I have to deal with the same situation in the future, for a plant that I really don't want to loose.

Nicole

rtsingleton · #2 01-24-2009, 10:50 AM

I'm not sure if increasing light would help, but getting to humidity to at least 60% and even 70% should help a lot. At 40% the new growths are probably desiccating as they grow. There are other root stimulator products on the market if you can't find KLN, not sure about the Netherlands though. Superthrive may help some... Stick some moss in the bottle to keep damp and then put the plant in there, if you can find some Physan 20 all you help to do is make a weak dilution of it and spray it in there lightly every now and then to keep the rot at bay, just don't leave it in standing water... Hope this helps!

Brooke · #3 01-24-2009, 08:28 PM

Think bright light but no direct sun.

Keep it warmer, not cooler.

Damp sphag, not soppy wet, will help keep the humidity up in the surrounding area and encourage root growth.

Superthrive on the damp sphag is great.

Mini g/h is good IF you can maintain some air exchange within the container. And remember, no direct sun if you use this technique.

You are half way to bringing the old pbulb back to life. Congrats!

Brooke

Blueszz · #4 01-26-2009, 08:13 AM

Thanks for your input!

I decided to make a mini g/h from a soda bottle. It has an opening on top and and opening in front which I can close if I think I need to close it. Nothing fancy, the front opening can be manipulated by lifting the upper part more or less :-)
I gave it more light and it's on sphag now.

Let's see if the the rootless speudobulb can provide enough energy until the tiny nub grows it's own roots :-)
I'll keep you updated on this one.

Blueszz · #5 02-22-2009, 12:05 PM

A month ago I asked you how to treat the bulb with that little thing growing on it's base. I thougt to let you know it's still growing. Slowly but it grows! The size is still about 1/4 of an inch but it's pushing out a very tiny root :-) Never seen such a tiny root, it realy is miniature

A few weeks ago I started growing live sphagnum, although I don't have lot's of it I made it a bed on top of nice green growing sphag. I hope now the root takes off!

What will be the next step (after the sphag?) Once the root(s) is longer (how long?) I would like to transfer it to s/h. Is that possible with this young plant or should I wait 'till it's older? What medium to use else? What about mounting it with live sphag (if I have enough by then?)

Nicole

Becky15349 · #6 02-22-2009, 12:15 PM

Hi Nicole! oncids really like moisture, but I think you should wait until this pbulb has several other growths before you put it into SH. I've had experience with backbulbs not relaly performing well in SH before they are mature - the seem to struggle to adapt to the SH and not grow as well as a mature plant. I would leave it where it is for a while - let it get some new growth on it and mature a bit. Also, be very careful using a bottle terrarium as this can create stagnant air and lead to rot...I'd put some more holes in the bottle and put it out with a fan nearby. Rot will quickly ruin everything you've worked so hard for, ya know? its the worse.

Blueszz · #7 02-22-2009, 12:31 PM

Thanks Becky for your quick answer! Great to hear your experiences with back bulbs.
Today I took it out the bottle g/h and layed it on top of some live sphag (in an open container), and hope this will encourage root growth. I'm watching it closely LOL, I don't want to loose it. I made sure the new growth and new root is just above the sphag. and that the rest of the back bulb isn't touching the sphag too much. Within a few days the new root might touch the sphag, by growing towards it!
The bottle I used had extra air holes already, it worked perfectly, never was able to measure humidity in it (so small) but rot was one of the reasons I didn't want to use the sphag and bag method.

I wonder why all this trouble for such a comon plant LOL, but I enjoy watching it and as I said before, it's a great learning experience.

blackorchid · #8 02-27-2009, 06:26 PM

Stick them in water and start water culture experiment, you'll like it.

Blueszz · #9 02-28-2009, 05:30 AM

Quote:

Originally Posted by blackorchid

Stick them in water and start water culture experiment, you'll like it.

That was one of my thoughts too but I don't have the guts to do it LOL. It was hard enough for me to move some plants to s/h
They are in s/h for a months now and all of them show new root growth!

blackorchid · #10 03-02-2009, 09:30 AM

Please post pictures of the progress. We all wanna see it!

And Btw, I don't think your plant will die in water culture (water with dilute fertilizer and very dilute rooting hormon). I have 2 catts saved from the big box store. It grows new roots after 2 weeks in water. and I think it will make the transition to other media easier. Remember you don't have to go for water culture if you don't want to, but it is a great way to prevent shock and help plant recover.