backbulb propagation question

[OhioBob]

I have this noid oncidium similar to a twinkle which I have had for ~5 years. Every spring the newest pbulb (last years growth) flowers then a new pbulb grows followed by the oldest one dieing. Not counting the oldest there is always 4 pbulbs which makes repotting in the same pot nice and simple.
This year the oldest pbulb fell off earlier than normal. Would it be possible to propagate another plant off this old pbulb? I am going to try the zipper bag and sphag trick. I also used a touch of K-L-N when I wet the spag. Do I have it right? Any other tricks to try... if this doesn't work I have next years pbulb?

[WhiteRabbit]

I'm baffled as to why the pbulbs die like that (I realize you didn't ask about that, but it isn't normal - unless I am misunderstanding - but pbulbs usually live several years, with the plant increasing in size)

I haven't tried propagating old backbulbs other than Cyms (which propagate fairly easily) - It is possible to propagate others, but I believe success is more iffy - hopefully some others can help advise you ...

Good luck!

[OhioBob]

I am also baffled by this too. My other oncidiums all keep the pbulb for years and get bigger until I need to cut them back. Still not sure what makes this one different though.

[RosieC]

It might be possible, but the bulb looks like it might already be dehydrated. I think you are more likely to have success with a healthy bulb that wasn't about to die anyway.

Like the other comments I wonder why they are dying off in this way. It doesn't seem normal.

[stefpix]

Also it does not look it has any piece of the rhizome attached. where is the cut? I think you need a bit of rhizome to get new growth from a backbulb.

[OhioBob]

I think the break is where the plant transitions from the rhizome to the pbulb. the bottom of the bulb is, for lack of better description, somewhat hairy around the edges. The cut zone looks like somewhat like the end of the stem left on the tomato. More like it was supposed to fall off instead of being torn off. If I can find one I will try to add a picture of the plant later.

So whether it lives or dies does the sphag and bag in the photo correct?

[sarahliz79]

Just wondering if you've checked out this blog... its all about propagating backbulbs...

Developing an Orchid Collection with Backbulbs

I've tried this method once but didn't have any success... Good Luck!

[chiquib313]

I've tried propagating a denbrodium cane with the sphag and bag method and it took about 6 months for two new growths to sprout from the old cane. I also have taken some backbulbs from a Dancing Ladies oncidium and mounted them on a stick with a little sphagnum moss and had them sprout in approximately 3 months. I find that the mounting method works much faster. I've attached some photos of the sprouting backbulbs.

[Leafmite]

The twinkles are cute. I have one and definitely want more mini, fragrant oncidiums.
A seedling mat might be helpful. I have done backbulbs but only with the onset of summer, as with cuttings. I use a plastic vanda basket (from Roberts Flower Supply here in Ohio) lined with sphagnum moss. For difficult cuttings, I place the little pots in ziplock bags and leave alone all summer. Best of luck.

[OhioBob]

Sarah,
I have visited that website a few times and will look again to see if I can find more info.
Chiquib and Leafmite,
Thanks also for responding. Love the pictures. I see this won't be as quick as I thought. I will have to look into a seedling mat as we keep our house pretty cold in the winter.
Maybe, even move it to work... warm and far enough from the window that it is bright but no direct sunshine. So now I am thinking in text and not out loud.