When to move repotted plants?

[The Mutant]

I recently, 29/9, repotted one of my roths and my gardineri and put them together with the Phals until they've established themselves. They had less than stellar root systems, but plenty of new root nubs, and it seems these nubs are very happy in their new substrate.

How long should I wait until I give them more light again? Should I keep them with the Phals for a couple of months, until their root systems have improved more? I think the gadineri is the one doing most well, while the roth needs more time.

I must confess that I only keep the chids with good root systems in lower light levels for a couple of days... It has worked so far with them, but since these two don't have any good root systems, I thought I should be a good girl for once.

 

[naoki]

I don't think you can make generalization here. You have to observe the plants, and some may take months to a year. If they are already starting to grow leaves, it's probably ok to move it back to stronger light.

Plants can hormonally adjust shoot/root ratio. With plants with minimum roots (i.e. dehydrated), strong light can cause loss of energy (this is called photorespiration) if it can't get rid of O2 by opening the stomata (to preserve H2O). So plants may try to adjust shoot/root ratio by getting rid of leaves. But if you can keep air humidity high, loss of moisture (transpiration) isn't too bad even under strong light. At the same time, plants do need photosynthesis to recover. So it's a delicate balance of environmental factors.

 

[The Mutant]

Okay, thanks naoki. I'll keep an eye on them and see how their root systems develop. They both had started to grow a new leaf each before I repotted them, and these new leaves are still growing, so it seems the repot hasn't set them back anything.

I think I'll keep the roth away from the T5 until it has a better root system, and the gardineri can move back a bit sooner.