Sharry Baby with shriveled bulbs
 

Hi All!

I've purchased my very first orchid about 3 weeks ago. The bulbs were plump and I didn't see any sign of it wrinkling. It was packed in sphagnum moss. I thought I would re-pot it in a bark and sphagnum moss mixture. I started to notice the bulb is beginning to shrivel. I've watered it once a week, and kept it in a spot with indirect sunlight.

The first picture was taken the first day I her home, the second photo was within the last 2 days.

Let me know what you guys think I am doing wrong.

Any advice would be appreciated.

Thanks

Welcome to Orchid Board.
Going from what was likely wet moss to an open chunky bark mix is quite a transition. So it is likely drying out too much in between watering. Did you soak the bark for at least a few hours, or overnight before using? New bark doesn't retain moisture easily for the first few months. Often old roots don't adapt to different media as well either so its best to wait till there is new root growth before re-potting. However, having said that, often with new acquisitions, it is sometimes best to re-pot right away as the condition of media and roots is unknown or can deteriorate if you wait.

I would just increase the watering. Run it under the tap and wet it very well, then let it drain well. I find my Oncidiums like to be damp, unlike some other orchids. The open media will help keep dankness and rot from occurring.

Yes. I prepared the bark for atleast 24 hours before repotting. The mixture is 80% bark and 20% moss.

I should water twice a week? Will the bulbs unshrivel?

Yeah, gotta say, none of my thin leaves get moss. (ie, oncidiums, Odontoglossums, Cambrias, milts and so on.) They just get plain bark of the appropriate size. (Fine) Also, a couple lost their roots when they came out the pot they were bought in. The damn things had rotted so badly that the entire root mass fell off like a badly glued wig.

I simply planted them in the bark as per normal and waterered them just like all the others. No, I didn't soak the bark.

I put thin leaves in a very shallow pot - 3-4 inches deep and 12 or 14 inches in diam. Fine bark only no moss. Where there were no roots to support them I just put 3 rocks on there to hold them upright. Both are upright and flowering.
I fertilise every watering with the lowest possible K Lite fertiliser.

Use a thin bamboo kebab skewer and leave it inserted in the bark. Pull it out to check. If the bark is approaching dryness, give it a good watering and also put the skewer back where it was in the pot for next time.

I like putting my skewers in the side of the pot low down, so you see what it is like there.

I put mine more to the centre and deep down because that is where it will stay the wettest and if not allowed to dry to the correct amount, can cause root rot.

I give my oncidiums a good soak for a few hours once a week, pbulbs usually plump up in a day or two if I had neglected them.

Thanks everyone for the help. I'll increase my watering regime for a few weeks to see if this helps plump those pbulbs back up.

I'll pick up some bamboo skewers next time I go for a grocery run.

I guess oncidiums don't mind being over watered as long as there is drainage. I'll keep everyone posted to see how things are.

I was gone for a week. I have some Oncidium hybrids that arrived here last October in sphagnum moss. They need a huge amount of water. I set them on the bottom of plastic trays filled with an inch / 2.5cm of water. On my return the water was gone, and they were dryer than I prefer.

Far less than an inch evaporated from buckets filled with water I left in the room to increase humidity.