Need Help With Onc. ampliatum & sphacelatum

[AaronM]

I have two Onc. that I could use a little help with.
The first is an Onc. ampliatum that I have mounted on a piece of cork. This is an orchid I rescued that was in very poor condition (sunburned and shriveled ) which is recovering nicely but has not shown any signs of further pseudobulb formation during the past six months. I keep it in my orchid room where the temp. is 65-85 degrees and 50-60% humidity with medium to bright light.
The plant has three psuedobulbs and maybe four new roots that are bonding well with the bark on one side of the plant. However the older roots, although white and firm, are not growing and are preventing good bonding along the other side of the mount. What can I do to stimulate more roots on that side? Also when can I expect some new growth from this plant? Lastly I could use any general care advice that anyone has to offer.

The second orchid is a 50 lb, mammoth Onc. sphacelatum with around 50 pseudobulbs and 5 spikes approximately 4 1/2 ft long. The only medium this plant is growing in is a massive mat made of thousands of old roots. This plant was also in pretty bad shape and had been sitting in on the ground for about a year. It is now hanging inside an east facing pergolla that is shaded for about 3/4 of the day.
I had to trim a lot of damaged leaves and tore out nearly 20 rotting or dead bulbs when I first brought the plant home and it seems pretty happy now.
What I find strange is that it is spiking and has been since January and has also been forming new pseudobulbs for the past ten weeks or so. Is this type of concurrent growth normal? Also, how long does this plant usually take to flower after it spikes?
The center of the "colony" is bare of psuedobulbs and I was thinking of moving a few of the actively growing clusters of bulbs from the outer edges to the empty center (after flowering, of course). Is this a good idea? When would be the best time? And should I add some medium to the center or just wire the transplanted sections in place?
Thank-you for any help you can offer.
Below are some photos. The one gallon watering can in the last picture is for scale.

[AaronM]

I know many people have read this posting. Please respond if you can answer any of the questions that I posed above.
Thanks again.
AaronM

[AaronM]

Am I to understand that no one in the Oncidium Alliance can answer any of the questions in this thread? None of you have any links to good information? Not a single person has information about these orchids in your personal library?
Apparently, all the really knowledgeable people hang out in the Vanda Alliance.
Oh yes I did!

Really guys anything helps. Maybe someone could address the question about whether or not it is normal for th Onc. sphacelatum to be in spike and have numerous new growths as well?

Thanks.

AaronM

[quiltergal]

I'm not familiar with either of these species but here is what I found on Jay's site.

IOSPE PHOTOS

IOSPE PHOTOS

It is my understanding that Onc's, as well as most sympodials, don't grow new roots from the old pbulbs. New root growth usually is initiated from the new growths.

If the sphacelatum were mine I would leave it be. If it's happy why mess with success?

Do keep in mind that while it may show lots of people have read this thread, many of them are guests and as such are not able to reply.

[kimstwin]

My Sharry Baby just finished blooming, and it is growing three new growths at the same time. I would leave the large specimen alone, unless you want to divide and share with friends. Any plant that large must be happy. I don't have any mounted Oncidiums, so I can't give any advice there.

[AaronM]

Thank you both for the responses. I know not every reader is a member. I was just hoping to goad some of you out there into responding.
"Mongo" is definitely happy but it struck me as out of character for an orchid to bloom and grow new pseudobulbs concurrently. I really hope this means it will bloom twice this summer. If even half of the new pseudobulbs were to bloom I would, quite literally have a wall of "dancing ladies".

[AaronM]

Here's a little enticement for the first person who can answer all the questions in the original post.
I will send you a healthy cutting from the Onc. sphacelatum when it finishes blooming!

[GreggC]

Leave the Gorilla sized plant alone. You are doing something it likes.


PS: Don't send plant. I have one. It was divided a year ago into three plants.

[Bird Song Farm]

Originally Posted by GreggC

Leave the Gorilla sized plant alone. You are doing something it likes.


PS: Don't send plant. I have one. It was divided a year ago into three plants.

Al

[Don Perusse]

Hi - As far as the sphaceltum is concerned if you can manage such a large plant, have room and want a "specimum" plant you might want to leave alone. They grow fairly fast and reliable bloomers. If it were me I WOULD NOT try to plant other pseudobulbs in the middle. After blooming I would divide into a large but manageable plant, leaving room for growth then divide the rest with a newbie, friend or other orchid grower. Now for the ampliatum, better known as the "turtle" orchid because of it's shape. It is one of my favorites as when the spike comes up the branching for the flowers are horizontal rather than arching down like other oncs. It is a very bright yellow, most striking in comparasion with other yellow onc. I've seen them on mounts but not as successful as in a pot as they like close quarters. I use tree fern w/redwood chips as the roots are fine like most oncs. I have both orchids and thank you for the offer but I don't need another spec. as they grow so well and easily divided. Hope this helps and good luck.