From my perspective as a mature Dendrobium, I communicate my need for division through my physical state. When my pot becomes a congested mass of pseudobulbs (my water-storing stems), with little room for new growth to emerge, I am effectively shouting that I need more space. This overcrowding leads to reduced flowering, as my energy is diverted to sustaining the massive clump rather than producing spectacular blooms. If you notice the center of the pot is a dense, old network of roots and back bulbs with little vitality, or if the potting medium has broken down completely, it is the perfect time to give me a new lease on life through division.
To make this transition less stressful for me, please prepare in advance. The ideal time for this procedure is in the spring, just as you notice new growths emerging from my base and new roots (often called "root nubs") beginning to form. This is when my metabolic energy is highest, and I am primed to recover quickly. Have ready a clean, sharp cutting tool like a sterilized knife or pruning shears, fresh potting medium suitable for epiphytes (like fir bark or sphagnum moss), and new pots. Water me thoroughly a day or two before the operation; well-hydrated pseudobulbs are more resilient and less prone to shock than those that are drought-stressed.
Gently remove me from my current pot. This may require some effort, as my roots are often tightly entwined. Carefully tease apart the root mass with your fingers, removing as much of the old potting medium as possible. Inspect my root system, trimming away any black, mushy, or desiccated roots with your sterilized tool. Now, identify natural divisions. Look for groups of at least three to five healthy, mature pseudobulbs with a visible new growth (or "lead"). Using your sharp tool, make a clean cut through the rhizome that connects these sections. Ensure each new division has its own set of viable roots to support it immediately after repotting.
Place each new division into a pot that is only slightly larger than its root mass. My roots thrive on being somewhat snug. Position me in the center, spreading the roots gently, and fill in around them with the fresh potting medium. Firm the medium lightly to hold me upright, but avoid compacting it too tightly—my roots need air circulation. Do not water me immediately. Instead, place me in a shaded, humid location for one to two weeks. This allows any root wounds to callous over, preventing rot. After this period, you can begin light watering and gradually move me to my preferred growing conditions with bright, indirect light. Withhold fertilizer until you see active new root growth, signaling that I have successfully established myself in my new home.
