Cattleya Growth Triggers
 

Background: I have three seedlings of Cattleya Amethystoglossa, all acquired from Miranda orchids last year in the same order (all seedlings: one aurea, one coerulea, and one albescens). At the time I got them, they were finishing up development of their newest growth and then went dormant and have been so for (what feels like) many months now. Roots have continued to grow and they look all around good, but I figured I'd see new growths by now. I went to check and noticed that one is now pushing a new growth that's moving pretty quickly, but the others just seem to want to grow roots only until the end of time.

My question is this: Is there a specific trigger that Cattleyas look for as to when to break from dormancy and begin pushing new growths or is it just a matter of "whenever they feel like they're ready"?

For reference all of these plants are in the same conditions, literally next to eachother, so I though I'd see bud break happen around the same time, but the albescens variety looks to be about 2 weeks or more ahead of the others.

If they crossed the Equator within the last year or so it would take them time to get accustomed to the new seasons. Different species likely have different growth triggers. It's often one or more of night length variation, temperature change, humidity change or water availability. I don't know what it is for this species.

Don't ever tire of an amethystoglossa forming roots! They frequently only do it once a year. And this is one species for which it is extremely important not to repot unless new roots are just forming.

I've observed the same thing with many of my bifoliates. They seem to grow roots all the time but growth is sparse and sporadic. I'm not sure if it's because it isn't receiving optimal growth conditions or that's just how they roll. My amethystoglossa and velutina in particular, are excruciatingly slow growing...

:hello Can't wait to see your velutina blooms. Had 2 that failed and after many yrs I still cannot grow Catts well. For me, velutina is the most beautiful, unusual C. I've ever seen.

Might there be a daily "moles of photons" trigger that must be reached?

I have no first-hand experience with those catts, but I noticed that my vandas were very responsive to light levels - they "awoke" in the spring, after a "dormant" winter, and grew actively all summer in my greenhouse.

I've found many bifoliates (amethystoglossa included) don't have a dormant period if you keep watering them. Try bumping up your watering and I bet it triggers the other two to grow.

Thanks for all the replies - I never really thought if there was a specific trigger to start new growth until recently when I realized the other two seemed to be just "sitting there" as it were. I grow in a larger terrarium, under lights, and can control light intensity, humidity levels, and temps so I'm going to increase the light duration as a starting point (maybe the intensity, just a bit) to see if that does anything - per Stephen, I may also bump up the watering a bit more. As far as the roots go, one of them (the aurea) was going so nuts, that I had to slip the root ball out of the pot, moss and all (how it came from Miranda orchids), mvoed it to a bigger pot, and packed some bark around it last fall; since then, it's now packed that pot with roots and started to crawl out of that one too - may post a pic later to demonstrate what I'm talking about.

Ah yes, seasonal cues like increased day length and warmth can certainly play a role!