The Difference Between Fertilizing and Not Fertilizing Phalaenopsis Orchids and the Correct Fertilization Method

Whether you fertilize your moth orchid (Phalaenopsis) or not makes an obvious difference at every stage of growth. The specifics are as follows:

Growth: Fertilizer supplies the moth orchid with the nutrients it needs. Proper feeding provides elements such as nitrogen, phosphorus and potassium, encouraging the roots to grow deep, the leaves to be broad and thick, and the pseudobulbs to be plump, so the plant grows quickly and robustly. Without fertilizer, it becomes nutrient-deficient, grows slowly, has weak roots, and its leaves turn yellow and wither, making it prone to pests and diseases.

Flowering: Fertilizing is crucial to the flowering period of the moth orchid. During flower-bud differentiation, fertilizer provides the material basis for bud differentiation, prompting more flower buds to form, and the flowers develop plump and large, in greater numbers, with vivid color and a long flowering period. Without fertilizer, flower-bud differentiation is difficult, the flowers are small and thin, pale in color, and the flowering period is short, lowering its ornamental value.

Stress resistance: Scientific fertilization can strengthen the moth orchid's ability to resist stress, pests and diseases. The nutrients raise the activity and strength of the plant's cells and make the cell walls tougher, so it can withstand adverse conditions such as drought and high temperatures. Its immune system is strengthened, enabling it to resist pests and diseases. An unfertilized moth orchid has poor resistance and struggles to adapt when the environment changes; it is easily infected by disease and attacked by pests, and in severe cases the plant dies.

Quality: Fertilizing can improve the ornamental quality of the moth orchid. The leaves are deep green and glossy with clear veining; the flowers are vivid and pure in color, with neatly shaped petals. An unfertilized moth orchid has pale, yellowish, lusterless leaves and dull, thin flowers, greatly reducing its ornamental value.

How to fertilize: During the vigorous growth period, that is, spring and summer, apply a dilute liquid fertilizer once every 7-10 days, choosing a fertilizer with balanced nitrogen, phosphorus and potassium, which comprehensively promotes plant growth. In autumn, to encourage flower-bud differentiation, switch to a high-phosphorus, high-potassium fertilizer, such as monopotassium phosphate, diluted and applied as a foliar spray or a root drench, once every 10-15 days.

In winter the moth orchid grows slowly, so the frequency of fertilizing should be reduced; applying a dilute liquid fertilizer once every 1-2 months is enough. It is best to fertilize in the evening, and avoid fertilizing at noon in high temperatures, to prevent the fertilizer from burning the roots. At the same time, follow the principle of "weak fertilizer, applied frequently," and never apply too much fertilizer at once.