I have Lc. Canhamiana 'Azure Sky' and it has bloomed for me most years, but usually only on one growth even tho it is a robust grower with multiple leads being produced each year. I keep mine under 2 T5's and the leaves do not go yellow and it has almost every single leaf since I got it a few years ago. It got so big, that I split it a year ago and still have at least 15 leads on mine now. It didn't bloom this spring and I assumed it sulked from re-potting. It was terribly tied up in roots and I had to get aggressive with it to split it. But mid summer this year when it had put out a number of new growths, I am seeing one (and only one) with a sheath on it. It seems the wrong time of year for a sheath on this, so I don't know. I have to wonder if this hybrid is just a reluctant bloomer. Mine does get shorter winter days and also much cooler winter days.

thanks silken...so most likely it is not too much light then, so perhaps I'll do some research to see how much magnesium they can handle, and I'll try adding a little epsom salt....thanks again for all the replies!

I do add Epsom salts occasionally but it is very sporadic and pretty infrequent. I also switch between tap water and rain water. If you are using R/O or rain water there is very little or no nutrient in it so that has to be taken into account. I often use MSU but also vary between several other quite common brands for a bloom booster such as Shultz. So maybe I cover my bases by flipping around a lot! It's a very robust grower but I can't say the same of its bloom habits under my care! Good luck with it.

One thing I noticed that seems strange to me, is I think it bloomed better when it was a smaller plant. Maybe someone can explain that for me.

So your friend gave you a division of hers/his. Did the mother plant ever bloom???
To me, it sounds like a mystery, maybe it is a mule?

Too much light may yellow the leaves (unless burn and kill), but the sheaths are usually still made.
Also, the production of the sheaths on this hybrid occurs while the plant is still in growth mode, which extends from late spring to early fall, sometimes even into winter. Then the sheaths will just sit there for many months. The shorter day length for a few months then the return of the longer day length signals the plant it is time to flower.
So I don't think not giving short light hours in the winter has anything to do with flowering in your case since your plant won't even make sheaths during the summer/fall season.

How does the yellowing on the leaves look?
Do the new leaves start out yellowish? or turn yellow slowly over time?
Is it even yellow all throughout or streaks? any brown specks? (signs of iron, mag, other element missing, but again, not likely since you are fertilizing)

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This hybrid, well, at least the Azur Sky, is very robust grower and great bloomer under HIGH light.
It is very likely that Silken's plant is not getting enough light. Big sized plant of this one should be flowering like crazy. I was in awe when I saw this plant in bloom at a nursery.

I grow all my catts (mostly BLCs and some LCs) right along the large bay window facing south. no curtains. Leaves do turn slightly yellow green on certain plants, but all are doing fine. I'm having the best cattleya year! :)
The only one I had to move away from this strong sun light was the mini cattt (Tropical Pointer) that was getting sun stroked. lol

My friend's plant has never bloomed, before or after she gave me the division. The new growth is always a good green with no marks at all, and many of them. The yellowing starts slowly and after approx. 4/6 + months (never noted how long it takes to yellow the entire leaf) they are yellow but are firm and never drop off. They are just like a good leaf except for the colour. I am going out of town for a few days, but when I get back I will post a photo for all to see. I use tap water and also use MSU and a variety of other fertilizers, and my others plants are doing just fine, except Bc Maikai ‘Louise’ AM/AOS is also showing the same yellowing issue but not as severe and it has not bloomed for me either, I've had it since 2010. Lots of growth though. Azure Sky also seems to have a touch of it too, but not as bad as the other two. I have 110 orchids so I guess it's not bad to just have a few that are problematic. So, I will post the photo by early next week. Thanks for all your help everyone!

Mine could use more light since it doesn't seem burned or too yellow. But it is under 2 T5's all winter and in summer it is still in the greenhouse which is so bright. So mine does not seem light challenged. My Vanda bloomed in that light! However, there are places where I can still give it more so we will see what next year brings.

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Bc. Maikai does need a LOT of light. I gave mine more this summer and see more sheaths than I did last year.

Good info! I'll give Maikai more light then.
Thanks and good growing!

Ok, with so many plants you grow, this one does sound like a mule. The fact that your friend's never flowered ever back it up too.

you know...I think I have to agree with you...overall I'm doing pretty good. I had a few paphs start to go yellow on me in January/February, just after blooming, so not sure if that is another issue altogether..but I did increase magnesium and they both came back with nice green leaves and have stayed green, so I may have been a little shy of fertilizer at that time as I was very busy...but I do believe I have a mule in that 'can of ham!' :rofl:
Happy growing!
Helen