Cattleyas light cycles and blooming

[silken]

Can't wait to see this one in bloom!

[rbarata]

Hello, my friends

I wonder if I should worry about this sheath colour...

[estación seca]

I've had bifoliate Cattleya and rupicolous Laelia hybrids bloom from dry sheaths.

[rbarata]

I think this one blooms in the autumn, at least there was a bud when I bought it. Even if that's the case, isn't it too soon for it to get dry?

[Roberta]

For some Catt species, this is normal behavior - they bloom from dry sheaths instead of green ones. (It's one of the distinguishing features between C. loddigesii and C. harrisoniana, which are very much alike), It looks like you may have a bud at the base of that sheath. Once the sheath is totally dry, some growers open it up so that moisture doesn't collect and kill the bud. I have done that with success sometimes but not always. Others likely have other advice on the subject. But the yellowing (and eventually drying) of the sheath is very likely normal for this plant

---------- Post added at 08:11 AM ---------- Previous post was at 08:08 AM ----------

Originally Posted by rbarata

I think this one blooms in the autumn, at least there was a bud when I bought it. Even if that's the case, isn't it too soon for it to get dry?

Not at all. When it's getting ready to bloom, the sheath dries. It'll be another month to six weeks before that bud emerges... it'll be autumn.

[rbarata]

It looks like you may have a bud at the base of that sheath.

In fact there is but... isn't it too small? Shouldn't it be bigger at this stage? It has been approx. this size since I noticed it for the first time, maybe one and 1/2 months ago. The sheath is 2 in long and the bud something like 1/4 in.

Once the sheath is totally dry, some growers open it up so that moisture doesn't collect and kill the bud.

Well, with an HR of 20% inside I don't thik I'll need that.
And I wouldn't venture into such procedure unless strickly necessary.

[estación seca]

Often the bud sits in the sheath for a long time before deciding to grow. My experience has been it is important not to let the plant go dry for very long at this stage or the bud may wither and die.

[rbarata]

I've been watering more often now, around every 5 to 6 days. As you've advised, I've been misting the roots and, inevitably, the top layer of the medium, so that aerial roots don't dry. Now, it still has some condensantion inside the pot and some roots still have a greenish tone. I think the right time is tomorrow.


One more thing... now that we are approaching autumn, it starts to get some direct sunlight in the late afternoon, at this moment for less than an hour.
But with temps of 100 at that time, I'm wondering if it isn't too much. I use the A/C set to 81 F to create some air movement and decrease the temp a little.
What do you think?

I was also thinking the sheath issue was somewhat related with it.

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[Roberta]

High temperatures aren't really the problem (background species come from hot climates) but direct sun is an issue, since it can create a real "hot spot" that can burn leaves. Filtered sun should be fine, as long as the leaf is not hot to the touch. I think the sheath is just nature doing its thing. As long as the sheath dries (not moist and brown) it's doing what it is supposed to do. If, when brown it starts to feel moist, then opening it up so that the bud doesn't stay wet is useful. Otherwise, I think you should just let it do what it wants.

[estación seca]

My experience has been that the sun lowers faster in the fall than the plant acclimates to increased sun, and they are at risk of burning, even if the leaves do not get hot. Also, without excellent air circulation, the sun will heat the leaves far above ambient temperature.

Shade cloth will help if you have a piece of that. You can put it inside a window or outside.

The best solution is a fan blowing directly on the plant. This will keep the leaves at ambient air temperature. I have some Cattleyas in a window where they get direct morning Phoenix sun (33 degrees north.) With a fan blowing directly on them, they did not mind temperatures to 104 F / 40C. I had to water a lot!

As I recall your nights cool down considerably. If they do, 100 F / 38C by day should not be a problem at all, so long as you keep the leaves from burning. A fan with good air movement would probably be as good as the air conditioner. But maybe the air conditioner is primarily for you and spouse. I would consider a supplemental fan for the orchids.