Blc. orphan: inflorescence "stalks" fail to develop; dry and die
 

A couple of years ago I bought a Blc. orphan at a botanic garden sale. I was told it had numerous "inflorescence stalks" (not sure of the term), but although the plant overall seems quite healthy, these buds all eventually become dry and straw-colored (as in the photo). Although I'm still very much an orchid noob, I have gotten Vandas, Phals, and a Dendrobium to rebloom, but tweaking the usual culprits (substrate, fertilizer, light, and temperature) seem to have had no effect. Suggestions? Thanks!

First, Welcome!

Those are sheaths, and sometimes a plant will just "decide" to not produce flower spikes, and makes "blind sheaths" . The plant does look healthy, so odds are good that it will bloom eventually, Can you tells us a bit more about your growing conditions? Watering, temperature, light, etc.?

Sheaths! Thanks for the term. As for conditions, we've got a sunroom, so relatively bright light; it has a mini split set to keep the room at 62°F in the winter, whereas in the summer I don't think it gets above 79°. The plant is now in a pretty standard orchid mix in a translucent orchid pot (bark, charcoal, some sphagnum), soaked in a dilute fertilizer mix as needed, on average probably weekly. I will say that its stems don't look quite like other Blc pix that I've seen; where these photos show slightly thickened green ribbed stems (pseudobulbs?), mine has thinner tan paper sleeves covering the stems.

The papery sheaths covering the pseudobulbs is normal. The presence and amount and shape depends on the parentage of the specific cross. (This one probably has considerable Brassavola nodosa in its background, which has long, thick leaves and small thin pseudobulbs) I suspect that the plant just has to mature a bit more to bloom.

62 deg F as a minimum is fine. Is it warmer during the day? It does appreciate daytime warmth. These do like lots of light. But the plant looks healthy, I think just patience. Think of those blind sheaths as "baby steps".

Okay, that's great to know. Thanks! In the winter it typically gets up to around 70° during the day. I did forget to mention that the humidity tends to be a bit lower than I'd prefer but we've yet to find a humidifier that doesn't quickly get the "pink mold" issues and other problems.

What fertilizer formula do you use?
How much do you mix per gallon?

Welcome! Many plants with substantial Brassavola nodosa ancestry need higher light levels all year to flower, compared to Cattleya alliance hybrids with thicker pseudobulbs.

There is also the possibility the plant isn't large enough to bloom yet.

I use Super Thrive at 16 drops per quart, which I believe works out to about 2/3 tsp per gallon.

Are you talking about the fertilizer or the "vitamin" formulation? I know there is some confusion there, the "supplement" manufacturer merged with DynaGro (that sold mostly fertilizers, and now there's a line of fertilizers under that name but they're also selling the "vitamins" under the same name. The "supplement" or "vitamin" formulation is supposed to be used at 1-2 drops per gallon... I used it for a couple of years as a supplement to my fertilizer at that low level, and started to see mutations in flowers, especially in the Cattleya tribe. I stopped using it and the problem went away. But we may not be talking about the same stuff. Ray can advise here.

Yeah, that seemed needlessly confusing. I started using Dyna-Gro when I switched to hydroculture, and I've always kept my concentration a bit lower than the 1 tsp. per gallon recommended for non-circulating hydroponics. However, now that I think about it, this may not be appropriate for orchids in a typical orchid bark mix.