As a Dendrobium orchid, my nutritional requirements are specific and change with my growth cycle. I am not a heavy feeder like some flowering plants, but I am particular about the balance and timing of my meals. I primarily need nitrogen (N), phosphorus (P), and potassium (K), but in varying ratios throughout the year. During my active growth phase, when I am producing new canes (pseudobulbs) and leaves, I crave more nitrogen to build strong, green tissues. Later, when I am preparing to bloom, I require a boost of phosphorus to support the development of strong flower spikes and vibrant blossoms. A lack of proper feeding will result in weak growth and few, if any, flowers.
Please feed me with a balanced, water-soluble orchid fertilizer. A formula with equal parts NPK, such as 20-20-20, is a good general-purpose choice. However, to optimize my performance, you should switch the formula seasonally. During my growth phase in spring and summer, use a high-nitrogen formula (e.g., 30-10-10). As days shorten and growth matures in late summer, transition to a high-phosphorus fertilizer (e.g., 10-30-20) to encourage blooming. Always, without exception, dilute the fertilizer to 1/4 or 1/2 the strength recommended on the package label. My roots are extremely sensitive and can be easily burned by full-strength solutions.
My roots and potting medium must never sit in accumulated fertilizer salts. These salts will damage my root system, preventing me from absorbing water and nutrients, ultimately leading to my decline. Therefore, you must adopt a "flush and feed" cycle. Water me thoroughly with plain, lukewarm water first, ensuring my roots are hydrated. Then, apply the diluted fertilizer solution. On the subsequent watering, flush the pot again with copious amounts of plain water to dissolve and wash away any residual salt buildup. A good rule is to "water weekly, weakly," meaning a diluted fertilizer application once a week, with a plain water flush in between if needed.
My feeding schedule is intrinsically linked to the seasons and light levels. When I am actively growing, which is typically from spring through early autumn, I welcome my weekly diluted meal. However, as temperatures drop and light levels decrease in late autumn and winter, I enter a rest period. During this dormancy, my growth slows or stops altogether. It is critical that you reduce or completely stop fertilizing me during this time. Any attempt to force growth will only result in weak, spindly canes and will deplete my energy reserves. Resume feeding only when you see clear signs of new growth emerging in the spring, starting with a balanced fertilizer.
