fertilize a flower spike

[naokit]

I think what Ray is saying makes sense. But there are some orchids which requires dry roots. In other words, even if the roots are exposed to the air constantly (mount), these species have reduced growths if the roots don't dry out at all. There is a scientific data about this. Can any one guess which species (or what kind of species) it is?

I haven't thought too much about the "dry" rest. Is there a possibility that those dormant plants actually have reduced immunity during the rest period? Some plant immunity is inducible (e.g. salicylic acid can induce some of the immunity). This suggests that expression of immunity is costly. If it is not costly, they should be always have high level of expression. So during the rest period when pathogenic attack could be less severe, plants may be lowering the immunity response. If this is the case, keeping them wet could be problematic when their defense is lowered. Any kind of the dormancy can be stressful for plants, so they may not be able to waste extra energy for keeping the guard up. This is purely wild speculation, but could it be a possibility?

[raybark]

Naoki,

I have always professed that tolumnias are like that - they originate on tiny twigs of shrubs on the windward side of Caribbean islands, where they get a nice rain, followed by a gentle, warm, blow-dry.

And then Eric Sauer showed me a lovely specimen growing in semi-hydroponic culture....

As to the winter rest, I'm too busy to cater to any particular plant, so my comments are based upon the experience of others, with my speculation as to why - wet or dry - it works.