Shriveling potinara (cattleya alliance hybrid) pseudobulbs after repotting

[Grim Tuesday]

I recently repotted my potinara after two of three buds blasted this past month, something I attributed to poor root conditions. The mix was very badly broken down when I got it out of its pot, but the roots actually didn't seem to be so bad. Nevertheless, I figured I had already done the damage getting it out so I put it in a new pot with new media. This new media is chunkier and holds less moisture than the old but I figured it should probably like that. I also used a terracotta pot (previously it was in plastic).

Since then, the previously juicy and succulent pseudobulbs have completely shriveled up, especially the older ones. It's quite large, about a dozen growths and I'm worried about the plant. So far the leaves all still look good. What should I do to make sure the plant will recover?

[KatieM]

How often are you watering it? Temp, humidity, light? That's a big change and at least in my experience they are sensitive. With the right care and patience it should come back but let us know how you are caring for it. Watering it more often would be my first guess but let's see what the experts say.

[Lil Duck]

Because you have changed the medium from water retentive, to non water retentive, you have to also boost the watering in return. As the new medium is so airy you no longer need to let it fully dry out for days on end, in fact Cattleyas love water they just need lots of air in the roots as well.
You are most likely underwatering your orchid.

[estación seca]

Repotting Cattleyas at the wrong time often causes problems. The old roots are damaged and may not be able to take up as much water as is needed until new roots form. When people aggressively cut off old roots the problem can be worse. Wait to repot until you see new roots just emerging.

If you think medium is too old and roots are suffocating, pull back a little of the medium from the top until you can see some roots. But don't repot. If the medium is bad but roots are good, I advise watering carefully until the next root growth period.

There are people who advise repotting orchids on arrival, or whenever they don't like the look of the old media. I don't do it that way.

It would take a lot to convince me to repot a Cattleya in the middle of winter in a northern climate. It probably won't be growing for a few more months.

[Ray]

The old roots, which grew in the crappy medium, are sub-optimal for the new environment.

At this point, the plant is struggling to take up water, but it is still losing it through transpiration.

Unpot it, give it a good soak for an hour or two in tepid water containing the stimulant of choice (I can recommend one, if you like), then repot it, watering it in with that same solution, the invert a plastic bag over it to trap humidity and slow the water loss. Keep it warm, moist, and shady.

[Optimist]

Originally Posted by Grim Tuesday

Since then, the previously juicy and succulent pseudobulbs have completely shriveled up, especially the older ones. It's quite large, about a dozen growths and I'm worried about the plant. So far the leaves all still look good. What should I do to make sure the plant will recover?

My take on this: I live in a crazy arid place and many of my orchids need to be constantly in water. I get cattleyas or dendrobiums whose p-bulbs desiccate badly and what I do is just put the pot in a larger pot full of water and leave it for several days up to a week, and the bulbs will pull in water and plump right up. The reason (I think) the bulbs desiccated is that new medium does not suck in much water so when you replace medium from old to new, you need to water much more often because the new medium is not "broken in." I went to using rocks or expanded clay (LECCA), because the stress caused to plants that are re-potted is just not worth it to me. So I get them used to rocks and lots of water (I mean LOTS to the point of semi-hydroponic). During the winter I do lay off on watering a month or so but if they start to show stress, I do water (I only water with RO water these days).

[Leafmite]

When repotting a Cattleya at the 'wrong' time (when there is not new growth), I keep the roots/medium dry for a few days to let them heal before watering. Some very finicky orchids, I pot with the roots completely exposed (weighted down by a piece of lava rock here or there) and let the roots begin growing into the new medium before adding more medium. I have never had trouble moving orchids from one type of medium to another...I just moved some Cattleyas from my experiment with NZ sphagnum moss to lava rock...just gave the roots a few days to heal and they should be fine. Many orchid roots are just very prone to infection that cause rotting as they grow exposed to the air either on trees, in pockets of rocks or in shallow, loose 'soil'. The medium, whatever it is, is just there to hold the orchid in place and provide some humidity around the roots. The key is that there is enough air circulating around the roots and that the roots get enough water to compensate for the water it loses through its leaves.
Give the orchid extra humidity while it recovers and, as we are getting close to spring, it should put out a new growth and be fine.

[Dimples]

A method I use for babying plants in medium that’s too-water-retentive is to water the pot thoroughly, let the pot drain, then set the pot on a dry fluffy towel with the drain holes in contact with the towel. The towel pulls out all the “extra” water that would otherwise be sitting in the pore spaces and potentially killing roots. This helps make sure there’s as much air in the root zone as possible until it’s time to repot. Paper towels work too but you need quite a few, so I strongly suggest cloth towels, old shirts, or whatever absorbent material you have handy.