Help - new orchid with different spots on leaves - is it diseased?

[MelC]

Hi!
I am new to owning orchids. I bought a new orchid less than a week ago. The tag says the following: Blc. Bryce Canyon Splendiferous AM/AOS x King of Taiwan x Oconee.
I notice some black spots on some of it's leaves pretty much right after I brought it home and also some weird spots on the underside of another leaf. When I watered it today (I let it get completely dry first) I noticed a mildew smell as well.
I've included pictures.
Is this plant diseased and if so, what can I do?
Thanks for your help!

[Roberta]

Welcome!

I would not worry about spots that I can see in the photos. What I WOULD worry about is the musty smell. Personally, I would never try to grow a Cattleya in sphagnum. I suspect that roots are in poor condition due to old and inappropriate medium.

In general, it is best to wait to repot until new roots are visible. But in this case, I would lhink about repotting now. When you do, gently clean off old medium, rinse well under the sink. Don't try to clean off all the old stuff because that would damage roots. Don't cut any roots even if they look bad - again, a good rinse under running water , then pot it up in fresh medium (I use bark, other people use inorganic media) . Even a bad root can hydrate the plant, and also help hold it in place firmly in the new medium (very important). Then you can water normally - it doesn't have to go completely dry (and probably shouldn't) if it has adequate air around the roots, which the fresh medium will provide.

[estación seca]

I suspect the plant was a bare-root plant recently put into that pot. The roots don't look as though they grew naturally into that medium. I agree with repotting into fresh medium as soon as it begins making new roots. Do it while they're less than 2-3 millimeters long.

If all the current medium is sphagnum, let it get dry before watering again. Watering sphag is different. Don't soak it thoroughly. Run water over the top for only 1-2 seconds so only the top becomes wet. Water will diffuse through the pot, leaving the moss barely damp and well-aerated.

A healthy Cattleya growing strongly during warm weather may use so much water it is appropriate to soak the sphagnum. But during cool weather, not actively growing, it is better to keep Catts. fairly dry.

[MelC]

There seems to be some rocks and bark in the pot as well.

Will I need to disinfect the pot that it's in now or am I better to buy a new one? It has slots on the sides and holes in the bottom.

I'll try to include another picture of what I think it's new grow? Correct me if I'm wrong

[estación seca]

If the pot size is appropriate, you can simply wash it with soap and water. Your photo shows a dormant growth bud, also called an eye, that might start growing. We're talking about repotting when you see new roots, which come from the rhizome. They start with bright green tips. As they elongate the tip remains bright green, and the older portion turns bright shiny white. Later on healthy roots turn tan or brown.

New roots tend to come from new growths. Sometimes they form just as the growth enlarges, and sometimes not until later. We're advising waiting until you see the new roots.