What are the precautions for fertilizing orchids at the roots?

The technique of fertilizing orchids is both simple and complex, and the following points usually need attention:

1. Different orchid species need different amounts of fertilizer. For example, Cymbidium faberi needs a large amount of fertilizer, while Cymbidium goeringii needs only half as much as Cymbidium faberi.

2. Different growing media require different fertilizers. For example, hard materials such as volcanic stone and Sendai soil contain no nutrients themselves, so more fertilizer is needed; while when humus soil and the like are used as the growing medium, since they already contain nutrients, there is no need to fertilize heavily, so the fertilizer requirement is smaller.

3. Different conditions of the plants also mean different fertilizer needs. Strong, large seedlings should be fertilized frequently and generously, while old, weak, diseased and young seedlings should be grown plainly and must absolutely not be fertilized, otherwise haste makes waste and death will surely be accelerated.

4. Multiple fertilizers should be used alternately. Using a single fertilizer makes it hard to guarantee the diversity and completeness of nutrients. Generally speaking, alternating organic fertilizers, inorganic fertilizers and biological bacterial fertilizers is best.

5. Fertilize according to the roots. Short, thick roots indicate too much fertilizer; blackened roots indicate fertilizer damage has already occurred; long roots indicate insufficient fertilizer; and many thin roots indicate severely insufficient fertilizer.

6. Fertilize according to the leaves. If orchid leaves are thin in texture and pale in color, it indicates a lack of fertilizer; if orchid leaves are thick in texture and green in color, it indicates no lack of fertilizer. If after fertilizing the leaf color becomes dark green, it shows the fertilizer has taken effect; if the leaf color does not change, it shows the fertilizer is too weak and the concentration should be increased.

7. Do not fertilize during the flowering period. Flower buds have a strong ability to absorb nutrients but a very weak tolerance. Once the flower buds emerge above the pot surface, fertilizing again will stimulate vegetative growth and inhibit reproductive growth, leading to poor flower bud development, petals that do not open fully, and flowers that fade early. Fertilizing during the flowering period will surely ruin the bloom.

8. Animal fertilizers and plant fertilizers must be fully fermented. Fresh fertilizer must not be applied; applying fresh fertilizer will inevitably kill the orchids.

9. Pay attention to fertilizer damage. If after fertilizing the leaf color turns yellow and the leaf tips scorch, it indicates too much or too concentrated fertilizer has been used. Water heavily at once or repot and change the soil to save the plant, otherwise it will inevitably die.

10. The three major elements in fertilizer must be combined scientifically. In the process of orchid growth and development, nitrogen, phosphorus and potassium are all essential nutrient elements. Applying only nitrogen fertilizer while lacking phosphorus and potassium will not give very good results either: the plant will grow leggy and the leaf texture will be soft, making it prone to pests and diseases; while favoring phosphorus and potassium fertilizers while lacking nitrogen fertilizer will make orchid plants grow short and small, with yellow-green, stiff, lusterless leaves, few new shoots and a plant prone to aging. Therefore, the relationship among the three elements must be handled well, and no single fertilizer should be over-applied. It is only that in the early stage of orchid growth there should be a little more nitrogen fertilizer, in the middle stage of growth a little more potassium fertilizer, and in the late stage of growth a little more phosphorus fertilizer.