Question
Hi, I have a Dendrobium orchid, the flowers and leaves died and fell off about a year ago, ever since i have just 2 long stems, they are both covered by a dry crusty skin, but look green and healthy underneath.  It now lives in my office, warm dry environment, and i've left it with our resident flower expert but even she can't get any life back into it. Can you help? Should I leave the crusty skin on or try and cut it back? thanks in advance.

Answer
Hi Hannah, I suspect the dry crusty skin is what is called a sheath and is a normal protective covering for the cane.  (We refer to the upright growth on the dendrobium as a cane). Dendrobiums are tricky to grow so it is not surprising that it poses a challenge. Dendrobium canes are unlike many other tropical orchids in that they have no water storage structure. (called a pseudobulb in other types of orchids).  Pseudobulbs protect the orchid from drying out during the protracted dry period they experience in nature.  Yet, dendrobiums also go through a rest period when there is no growth. The rest period requires only occasional misting to keep the canes from shriveling.  The tendency for people to water dendrobiums during the rest period can result in either premature (and therefor weak) new growth or, even worse, root rot or rotting of the growth "eyes". I suspect that there is one (or both) of two reasons for lack of growth. The most benign of those is that it still hasn't emerged from its prolonged rest period.  It may be misted, but not watered, until it begins new growth. The second possible reason for lack of growth is that the "eyes" from which new growth emerges, have rotted away leaving no tissue from which new growth can emerge.  These growth eyes are at the base of a cane and are covered by a sheath. If you see a slight swelling at the base of the cane, your growth eyes are probably fine.  Without these "eyes" your dendrobium will not produce new canes.  Then, the only option, is that the dendrobium may produce new growth from a node (ie joint) on one of the canes.

Most dendrobiums are of the warm growing type. They thrive on heat and sunlight. Once the plant emerges from its dormancy, and after the new growth is about  4-5 cm in height, you should increase both warmth and light.  At that time, you may be in spring and will be able to summer the plant out (as long as the temp remains above 50 degrees F.