I am from South Africa and have bought one of each (mounted) about three years ago. Both have suddenly slowed in their growth and have become shrively like they are desiccated, although both have spindly new growths, but they show no new roots.

All my other mounted cats are doing well, and they have not been disturbed or anything, so I am concerned. I am considering taking them off the mounts and potting them once the new roots appear. Is this a wise move, or should I try something else.

They receive about 14 hours of strong light. I water and feed daily due to our high day temperatures in summer (between 28 70 36 degrees C) with a quarter strength mix alternating between seaweed extract and a balanced NPK fertilizer, alternating. I supplement with calsium sulphate, magnesium sulphate and iron chelate in very weak quantities.

Any advice will be appreciated.

I am hoping they will last until I can repot them into a medium bark medium for want of anything else to do.

First, Welcome.

(I tidied up your duplicate post)

Rather than further stressing the plants (which removing them from the mounts can do) consider just putting them in a pot or basket (mount and all) and fill in around them with bark. That will let you increase the moisture (which they seem to need). You may also want to give them a bit more shade. I grow both of them (in baskets) under 60% shade cloth. They like light, but they may be getting too much.

Thanks Roberta, that sounds like some solid advice. My orchids are inside a polycarbonate clad hothouse over which I have put 60 % shade cloth with a 300 millimeter gap between the two. I am running a 5 kilowatt extractor fan sucking air in through a radiator to cool and humidify the atmosphere inside my orchid house, so I'm pretty comfortable with the amount of light the plants are receiving, but your idea of potting the mount makes sense. Thanks again.

Also, what other Catts are you growing (that seem to like the conditions)? Different species (and their hybrids) have different requirements. C. loddigesii and harrisoniana may want to be a bit cooler... mine grow outdoors, winter lows typically around 4 deg C , occasionally a little lower for a few hours, days in the 15-18 deg C range, sometimes a bit higher. Summer lows around 20 deg C, summer highs in the 27-35 deg C range. Of course, a species may tolerate cool but not require it. Just thinking about what factors might make the behavior of these species different from the rest of your Catts.

I have most of the unifoliate and bifoliate cats. My Cat Rex I grow a little cooler (alongside my sophronites) and my Eldorado loves the higher temp ranges. Everything else is sort of inbetween, except for my Walkerianas and Nobiliors, which I keep separately in a makeshift box with very bright light, lots of air movement and nightly feeding and watering. I've just moved my Schillerianas in with them as an experiment. I try to emulate the conditions they grow in in nature, but sometimes it's difficult, because we have a phenomenon called "loadshedding", which makes it difficult to automate things like watering, lighting, fans, etc. I have been of the belief that Loddigessii, harrisoniae and bowringeana have similar kind of intermediate requirements, which is why I placed the post, but it appears the former two at least, require less light.

I grow bowringeana under the same conditions as the others... so the differences for loddigesii and harrisoniana must be pretty subtle. My overall light level may be a bit lower. (I don't measure it, it's whatever Mother Nature gives me.)

Other than the Walkerianas and Nobiliors, I tend to do the same. I try to keep my temperature range between 15 degrees C and 35 degrees C in the summer and between 8 and 28 degrees C in the winter. I use discarded underfloor heating mats just below my benches to keep the temp up in the winter when it drops as low as minus 3 degrees C. It works very well. I find that keeping a 15degree day/night differential is also rewarding. My biggest challenge is maintaining a high enough humidity constantly. Running the pump and extractor fan continuously is almost cost-prohibitive, but essential, as it makes a massive difference.