Brown root tips in Laelia

[Roberta]

I think you'll be glad you waited... When you see new root growth (so that any old roots that get damaged will be quickly replaced), that would be the time to repot if you still want to.

Epiphytic orchids (which describes nearly all that you are likely to be be growing) definitely play by a different set of rules. Because they have evolved to grow on trees and tree branches with their roots exposed - in places where humidity is high and it rains a lot - they really want "humid air" more than "wet" around their roots. The "air" part is really important. But if you visualize these plants growing on a tree, their behavior makes more sense. It rains, then the sun comes out. Roots go where they want - to hang on, or to capture the water and air that they need. Also, since they grow slowly, they need very little fertilizer, too little might slow the growth a little but too much can be deadly.

[AnitadeWaard]

Thanks again Roberta, that does help me to understand these interesting creatures! I set up a humidifier and a fan, but I see how the humid air doesn't necessarily get into the roots if they are in pots... I'll keep an eye on them and move into the open air if they don't seem to be thriving.

[Roberta]

Originally Posted by AnitadeWaard

Thanks again Roberta, that does help me to understand these interesting creatures! I set up a humidifier and a fan, but I see how the humid air doesn't necessarily get into the roots if they are in pots... I'll keep an eye on them and move into the open air if they don't seem to be thriving.

They actually do get humid air in the pots... that's why one uses bark rather than dirt. There are lots of air spaces. When you water, the water flows through (pulling air behind it) and wets the surface of the bark. As that water evaporates, there's plenty of humidity in the pot. That's why the ''pot within a pot" allows root growth - the roots get wet (they have a spongy coating called velamin that holds some water) the space between the pots provides air, and bingo, humid air and happy roots.

The humidifier really isn't necessary. The fan... creating gentle air movement is helpful, helps that evaporation process and also tends to reduce problems with insects like scale and mealybugs.

Orchids that need more moisture can be potted in small bark, those (like the Cattleya group) that need to dry out, larger bark. That way, with a mixed collection, all can be watered the same and each gets the effect that they want.