From our perspective as Dendrobium orchids, dormancy is not a choice but a vital, ingrained survival mechanism. It is our response to predictable seasonal changes, primarily a significant drop in temperature and a reduction in available water. In our native habitats across Asia and the Pacific, the cool, dry season signals that resources are becoming scarce. To push new growth and flower during this time would be energetically disastrous. Instead, we enter a state of rest, dramatically slowing our metabolic processes to conserve the precious energy and water stored within our pseudobulbs. This period of quiescence allows us to endure harsh conditions and prepare for a spectacular display of blooms when favorable conditions return, ensuring we attract pollinators at the optimal time.
You must learn to read our signals, as the timing is not universal for all Dendrobiums. Broadly, we fall into two categories. For many deciduous species, like those in the Dendrobium nobile group, the trigger is the combination of shorter day length and, most critically, a distinct drop in nighttime temperatures, often needing to be below 60°F (15°C) for several weeks. Our leaves will begin to yellow and drop—this is a natural process, not a cause for alarm. For evergreen species, like Dendrobium phalaenopsis, the rest period is less about leaf loss and more about a noticeable slowdown in growth. We may not drop our leaves, but our canes will appear static, and we will cease producing new roots or leaves.
To properly support us during this critical phase, your care routine must change dramatically. First, and most crucially, you must drastically reduce watering. For deciduous types, cease watering altogether for the entirety of the dormancy period, which typically lasts 4-8 weeks. The slight shriveling of our pseudobulbs is normal; they are our water reservoirs, and we are using those stores. For evergreen types, reduce watering to a bare minimum, perhaps a light misting of the potting media every few weeks to prevent the roots from desiccating completely. Second, you must withhold all fertilizer. Our roots are inactive and cannot absorb nutrients, and any salts in the fertilizer will damage them. Finally, ensure we experience those cooler temperatures, ideally with a 10-15°F (5-8°C) difference between day and night.
The end of our dormancy is signaled by the emergence of new growth, typically flower buds (flower spikes) or new vegetative growths (keikis or new leads) from the base of our pseudobulbs. This is your cue to gradually resume normal care. Do not immediately flood us with water. Begin with light, increased misting, and slowly work back to your regular watering schedule as the new growths establish their own roots. This careful reactivation prevents rot and allows us to transition smoothly from our state of rest back into a period of vigorous growth and flowering, fueled by the energy we so carefully conserved.
