It seems that roots encountering the air will continue growing if it's humid, but they tend to stop under the low-humidity conditions of the windowsill. For potted orchids, it isn't of much consequence usually, since we focus on watering/fertilizing the pot.Originally Posted by peteMc
Backbulbs can sometimes put out new growths years later for no good reason...maybe they just feel like it. I've never heard of inducing new growths by turning the pot, but that's not to say it wouldn't work, I just haven't heard of it. One thing that can be done to induce new growth formation off a backbulb (short of slicing it off and sphag & bagging it) is to cut the rhizome halfway, i.e. between a couple of old bulbs and the bulk of the mature plant. New growth will sometimes be induced off the back portion. This is primarily done for those desirable catt clones that just march straight across the pot, never inclined to produce a side growth, but I suppose it can be extended to other genera.