The name Dendrobium translates to “living on trees”. Dendrobium is a hugely diverse genus with some varieties being deciduous and dropping their leaves in early winter, while others are evergreen.
Evergreen Dendrobiums like constant warm conditions and have pseudobulbs that are more spindle shaped than the deciduous group. The deciduous variety won’t bloom without a dry rest period for several months or even a cold snap. During this rest period they lose their leaves. They are harder to master than the evergreen Dendrobiums.
The deciduous variety requires plenty of warmth and moisture in the summer. A cool rest in the winter helps to set buds on the canes.
Evergreen varieties are best planted in shallow terra cotta pots like azalea pots. Evergreens grow continually and bloom when the latest bulb has matured. They must never be exposed to cold temperatures. Keep them 60oF to 90oF and should never go below 50oF, because that will cause leaf drop. Keep them moist at all times. Fertilize with a 30-10-10 while actively growing.
Most Dendrobiums, regardless of the type, want bright light and small pots. Well-drained mixes like rock often works well, as does medium bark with coarse perlite.
If your Dendrobium is not blooming, it is because the light is insufficient. With a lack of light over time you will start seeing weak and thin steams.