leaves dropping
 

This dendrobium phalaenopsis tipe of mine Is losing its leaves is this normal for then, if not what can I do?

Many species of dendrobiums will lose their leaves and go dormant for part or most of the winter. That would be my best guess as to what's happening here (honestly not too familiar with den-phals so this may not apply, but it's my best guess). If this is the case then it'll bounce back and send out new shoots in the spring with some warmth.

My experience with a den phal is that they are very touchy about watering and they will loose their leaves very easily. It seemed to like getting the top of the media misted everyday instead of a heavy water. It also did better in a clay pot. That is just my experience.

Check the roots, your media might be too wet for too long. I've grown den. Phal too, it likes to dry out between water. Den. Phal is very robust, it will bounce back if you can provide more air to the roots. I'll say make a few more holes on the side of the pots if you are using big pot.

I water him only once every week. RRoots look fine

Then might just be the leaves were getting old. Keep an eye on it. Den. Phal likes bright light. I grow my in south facing windows.

They may also drop leaves if they've gotten too cold