Yellow mottled leaves and losing new growths on Catt

[bethmarie]

I got this from the greenhouse in October - I just repotted it yesterday, from lava rock to bark.

Aside from the blecch factor of finding the lava was harboring many, many centipede larvae, it wasn't as bad as I feared. Lots of dead roots, but lots of live ones too, though the live ones aren't looking fabulously healthy.

The pics show the two issues this Catt hybrid is having. One, the yellow mottling of the leaves, and two, new growths blacken and die at various stages of development. Not rotten-- still firm, but decidedly dead.

Thanks for looking!

[WhiteRabbit]

[Leafmite]

How are you growing this exactly? Temperatures, lighting, fertilizer, etc.
I am surprised that no one responded but here it goes....
A few tricks to growing Cattleyas:
Plant them so that only the roots go down into the medium and water by dipping the pot into a bucket. This helps to prevent water from getting into the new growths which can rot them.
Calcium. Some Cattleyas, for whatever reason, seem to need more Calcium than other Cattleyas. I have no idea why some need so much Calcium but Black growths can often be a sign of Calcium deficiency, even when they don't seem soft on the outside.
Iron and magnesium. I find that when my Cattleyas are growing like crazy, they want more iron and magnesium (as well as Calcium). I add a little Ironite to the bottom of the watering can during the summer. The faded leaves might be a sign that they need more magnesium and Iron.
Roots. The only way I grow good roots on mature orchids is by using either leca/red lava rock and basket-type pots or Vanda baskets. If the roots are rotting, it is a sign that you need to allow the roots to have more access to air. You can encourage healthy roots by giving them a dose of a kelp/seaweed mixture once a month. I bought some this past spring because I had accidentally bought a bunch of orchids that had no healthy roots. It is great stuff.
Temperature. Some Cattleyas, depending on what their ancestry is, need warmer temperatures than others. I am not sure what your temperatures are but with the new growth, this one might need it to be warmer. Yellowing leaves and blackening new growth sometimes indicates that it is too cold.
Flushing. Sometimes, blackening growths and poor roots are due to the build-up of fertilizer. It is important, especially with red lava rock and LECA, to flush the pots very well at least once a month to prevent this. Over fertilization of any plant or 'salt-build up' can cause these symptoms.

I hope this helps. As I don't know exactly how you have been treating this Cattlyea, I am just giving you some things to consider.

[wintergirl]

I too like to plant my catts shallow. I keep the rhizome above the media. One trick I find helpful is when you water have a nice warm water run over your roots until all turns green. It flushes the pot and seems to promote root growth IMO. Then don't water again for 10-12 days. I always put ground up egg shells in all my catts, I never get black spots anymore.

Also make sure there are plenty of air holes and drainage in sides and bottom of pot. If you don't have good roots stake/stabilize the plant to help new roots grow.

[katrina]

Has the "mottled" leaves always been that way or did they just recently start to turn colors?

It appears to be the older growths?

If it's the older growths and they were that way prior, then it could've been a calcium deficiency early in their development. I have a few that are/were like that and it seems they just needed extra - extra Calcium. Adding a bit more to their regimen seems to have solved the issue in the new growths. The old ones will forever be that color but the new growths will develop normally. So, if it's just the older growths and it's been that way for awhile then you might just want to make sure that all future supplementation includes a regular extra dose of Ca/Mg.