dieback on dendrobium infundibulum
 

About a year ago, I converted most of my plants to semihydro. The results have been wonderful on phalaenopsis, cattleya, paphs, miltonias, and several types of dendrobiums. The single exception has been my dendrobium infundibulum. In both our hot, humid summers and the drier, cooler period indoors, it forms new shoots, but the shoots immediately start to dry and die from the outside in. I gave it a bit of a cool, dry rest last winter, as most sources recommend, but the problem continues.

Is there some reason why this one species wouldn't grow in semihydro or would be extremely slow to adapt? It's supposed to be an easy grower, or so I thought. I did check for fusarium, but there's no sign of it.

It could just be that this particular species isn’t working in semi-hydro for you in your conditions. I have some genera that do great in s/h ( Oncidiums, Phrags) and some that don’t (Phals, Cattleyas, Dens). Doesn’t mean it will not work for others, but those ones just won’t adapt well for me.

It sounds like it is dehydrated if your new growths keep shriveling up before they root. Are there any heathy roots right now? If you want to keep it in this set up you could always try watering more frequently, maybe every other day, until you get it established. How old is it? I have a young one that I have been keeping warm, watering only a little less throughout the winter, and it will grow year round. Until it gets a bit older, I try to keep the night lows at 60F.

Edit: question about your summer temps. How hot is hot? And do you have a cool down at night?