Repotting in September
 

Hi all,
I have some Cattleyas and Potinaras that need repotting. I grow my plants under a 2-foot-long and 2-foot-high plant table with two LED lights. It is against a south-facing window that gets direct sunlight for a couple of hours daily. Is September a good time to repot or is it getting too close to the early winter?
Thanks!
- alanbar

Don't folliow "human" calendar. Follow the plant's calendar. Right as you see new roots forming, that's the best repoting time as new roots will adapt to the new medium.
Note that different Cattleyas have different rooting times so using your observacional skills is what you must do.

My winter is 40F cold consistently, and yet some of my catts were sending out roots. I don't understand it, but if I see new root develop I just pot it up anyway.

I think it was said well, the plants calendar is far different than ours.

Yes, listen to your plants. New roots whenever they happen, that's the signal.

(Just an example, Laelia anceps always do their rooting in late fall and well into winter... and that's the only time for mounting and potting them. And they're spiking at the same time. That's OK, time to just do it.)

Repotting Time
 

Hi,
Thanks for the responses. If the plant is developing a pseudopod, is it a good time for repotting?

The time to repot is when new root nubs are 1-2 millimeters long. Any longer than that and they are likely to be damaged in repotting. The plant may not make more roots for many months, and may not be able to take up enough water with damaged old roots.

Not all orchids make new roots quickly after a new growth forms. This is the case with many bifoliate Catts.

So wait until you see new roots.

Cyms, especially the Asian ones that bloom at the end of summer, probably OK. (Though I have even gotten away with repotting the standard ones this late) If it is doing a new growth, it will be doing new roots at the same time, so that would be the right time anyway.

I do not grow under lights and I live in Ohio so, in my circumstances, getting Cattleyas out of old medium is essential. It is amazing how quickly dim, dark cold windows and old bark medium can rot roots...no matter what one tries. I do not miss the days of using bark. Just a note...in my growing conditions, I find that Cattleyas are not too picky if I mount them out of season.

If you can wait until you see some roots, that is certainly best. If you live in a cooler climate, you might not have much of a choice if the medium is decomposing and compacting.

That tells a subtil truth, that all decisions arent easy, what Has to be done can not resonably be avoided.