Correct Methods and Precautions for Foliar Feeding

The leaves of orchids have stomata, with about 85% on the lower surface and about 15% on the upper surface. Stomata are the portals through which gases and water enter and exit during photosynthesis and respiration in plants. We dilute fertilizer into an extremely thin solution and spray it on the upper and lower surfaces of the leaves; the fertilization method by which it enters the leaf through the stomata or by imbibition is called foliar feeding. The advantages of this method are (1) rapid fertilizer effect; (2) economical; (3) for orchid plants with rotted roots, it is the only method of supplementing their fertilizer; (4) it does not easily damage the roots; (5) it does not cause excessive water in the pot and thus poor ventilation. For fertilization to achieve good results, it is also related to factors such as the brightness of the orchid room, air permeability, and watering. Only when photosynthesis is vigorous can the greatest effect be obtained. If the orchid room is dark and management is also poor, then although the above method is followed, even with frequent fertilization, its effect will inevitably be halved. (Zhang Fengrong)