Encyclopedia of Orchid Fertilization Knowledge, a Detailed Guide to the Orchid Grower's Handbook

OrchidsCultivation:OrchidsEncyclopedia of Fertilization Knowledge

“One flower of the crop depends entirely on fertilizer” - this farming proverb applies just as well to orchids. Orchids are fertilizer-loving plants, and the nutrients in the potting medium alone can hardly meet their year-round growth needs. After an orchid has grown in its pot for a long time, the nutrients in the medium gradually decrease, so appropriate fertilization is needed. Fertilization is one of the important links in orchidcultivation, and it is also an extremely difficult skill to master in orchid growing. It is very necessary to study it carefully, explore it carefully, practice it carefully, and summarize it carefully.

I. The main fertilizer components orchids need

1. Nitrogen, mainly promotes vigorous stem and leaf growth and deep green leaf color. When nitrogen is deficient, the leaf color turns pale yellow and the plant grows slowly. Among nitrogen fertilizers, soybean cake, oil crops and urea contain relatively large amounts of it.

2. Phosphorus, can promote well-developed root systems and a substantial plant, and promotes the formation and development of flower buds and leaf buds. Among phosphorus fertilizers, bone meal, fish meal and superphosphate contain relatively large amounts of it.

3. Potassium, can dissolve and transport nutrients to the cells, making the plant firm, the stem and leaf tissues substantial and upright-growing, and enhancing the plant's resistance topests and diseases. A potassium-deficient plant will become shorter, its leaves will soften, droop and scorch, and growth may even be inhibited. Potassium is mainly contained in plant ash and potassium inorganic fertilizers. The above three fertilizer components are the main fertilizer nutrients that promote orchid growth. What we usually call fertilization mainly refers to applying these three fertilizers: nitrogen, phosphorus and potassium. In addition, during their growth process orchids also need trace elements such as calcium, magnesium, sulfur, iron, manganese, copper, boron and zinc. But under normal circumstances, the medium will not lack these, so generally there is no need to add them. If they are lacking, this can be solved by changing the medium, or by topdressing with a full-price synthetic organic fertilizer.

II. Types of fertilizers orchids need. Fertilizers are mainly divided into two major categories, organic fertilizers and inorganic fertilizers. In addition, there are high-efficiency synthetic flower fertilizers and biological bacterial fertilizers.

1. Commonly used organic fertilizers:

a. Human and livestock manure; urine is used after fermentation and decomposition, called “golden liquid” in ancient times, with nitrogen as its main component; cow, sheep, pig and dog manure, after fermentation, can be used either as dry fertilizer or made into fertilizer water and used after dilution. This kind of fertilizer has a complete set of nitrogen, phosphorus and potassium components.

b. Decomposed fertilizers; there are many kinds of traditionally used decomposed fertilizers, such as soybean cake, rapeseed cake, fishy water, chicken feathers, fish intestines and so on, soaked and fermented, then diluted for use after 3--6 months of decomposition. Decomposed fertilizers also have a relatively complete set of nitrogen, phosphorus and potassium components.

c. Grass juice, made by decomposing tender grass grown in spring or early summer into a liquid, with nitrogen as the main fertilizer component.

2. Commonly used inorganic fertilizers: commonly used inorganic fertilizers include potassium sulfate, superphosphate, monopotassium phosphate, urea and so on. These inorganic fertilizers have varying effects on orchids, and all contain certain inorganic salt components, so they must be used with caution.

3. High-efficiency synthetic organic liquid fertilizers and biological bacterial fertilizers:
a. Lanjun Wang, a full-price nutritional element, has the effects of promoting roots, stimulating buds and strengthening seedlings.
b. Zhiquan, a comprehensive mineral biostimulant, has the effects of promoting roots, stimulating buds, improving vitality and preventing viral infection.
c. Xishuo, a natural algae fertilizer and soil conditioner, contains various elements as well as natural plant hormones and active bacterins, and can resist cold, drought and moisture and inhibit viral infection.
d. Cugensheng, a comprehensive root nutrition supplement for plants, makes the roots more vigorous, thereby making orchid plants grow rapidly, and can also inhibit viral infection.

4. Long-acting slow-release granular fertilizers, such as the American-made “Magic Fertilizer” and “Scotts”, and the Taiwan, China-made “Yiduo”, etc. A few granules placed in the pot slowly release fertilizer components throughout the year.

III. What fertilizers orchids need during their growth period. During the growth period of a year, the fertilizers orchids need are:

1. Bud-breaking fertilizer, applied to break dormancy, promote early sprouting and gain a longer growth period. It can be applied when the daytime temperature reaches above 15c and the nighttime temperature is not lower than 5c. Inorganic fertilizers (such as urea and monopotassium phosphate) and biological bacterial fertilizers are best applied as foliar sprays.

2. Bud-stimulating fertilizer, applied to promote early and abundant sprouting and to gain effective early-autumn buds. It can be applied 7--10 days after applying the bud-breaking fertilizer.

3. Root-promoting fertilizer, when the leaf buds extend about 3cm above the pot surface, there is a pause in growth, and at this time new roots gradually grow, entering the vegetative growth and reproductive growth stages. At this time more nitrogen, phosphorus and potassium elements are needed to promote rapid growth of new roots.

4. Growth-promoting fertilizer, applied to meet the needs of orchid plants for new buds to develop quickly, grow quickly and mature quickly, and to be able to sprout a second time in late summer and early autumn, and to gain early sprouting and early maturity of the second batch of buds. It is the type applied for the longest time and the greatest number of times in a year. It is best to alternate organic fertilizers, inorganic fertilizers and biological bacterial fertilizers, and to alternate root application and foliar application.

5. Flower-promoting fertilizer, applied to promote the development and growth of flower buds and achieve the goals of more flowers, larger flowers, brighter colors and fragrance.

6. Cold-resistance fertilizer, stop applying nitrogen fertilizer 30 days before the orchid plants overwinter, and apply more phosphorus and potassium fertilizers to help them overwinter, because phosphorus can lower the freezing point of plant cells, and potassium can increase the plant's cellulose, making the stem and leaf cortex tough. Choose monopotassium

II. phosphate for root watering or foliar application.
According to Mr. Shen Yuanru: after potted orchids are brought out of the room in early spring, fertilize twice around Qingming, with half a month between each application; during the period when young buds and new roots sprout, more nutrients are needed, so apply fertilizer to strengthen the plants; during the plum rain period the daughter plants grow very fast, so choose a sunny day and fertilize 1--2 times; at Minor Heat, if the orchid plants are thin and weak, apply a light fertilizer once as a topdressing; from White Dew to Autumn Equinox, apply a light fertilizer once as the last topdressing; after Cold Dew, if there are autumn stems, apply a light fertilizer once more as a topdressing.

IV. Basic methods of fertilizing orchids. There are two basic methods of fertilization: base fertilizer and topdressing.
Fertilizer added directly and mixed into the medium is called base fertilizer. Because adding fertilizer to the medium is hard to control, easily breeds pests and diseases, and easily burns roots and damages orchids, in recent years generallyorchid growersno longer use it. Topdressing methods again fall into two kinds: root-system fertilization and foliar fertilization.

1. “Root-system fertilization” means pouring fertilizer into the medium so the roots can absorb it. Root-system fertilization methods include: “pouring” and “soaking”. “Pouring” is the most commonly used method, which means pouring the fertilizer solution along the pot edge into the medium. “Soaking” means placing the orchid pot directly in the fertilizer solution to soak. Both of the above methods have advantages and disadvantages; only when used properly and applied reasonably can they be beneficial without harm. The root-system fertilization method we commonly use refers to the first one.

Root-system fertilization should pay attention to the following points:
First, the concentration must not be too high; fertilization should be little, light and frequent, and must never be excessive, otherwise fertilizer damage easily occurs and causes death. Even if the plant survives by luck, it is hard to recover after being damaged.
Second, when fertilizing, avoid splashing onto the leaf surface and pouring into the leaf center, especially pouring into new buds that have already split, which easily causes rot; pour around the pot edge.
Third, water with “reviving water”. After fertilizing in the evening, water with “reviving water” the next morning. It has two effects: first, it washes away the fertilizer solution adhering to the orchid leaves; second, it rinses away the excess fertilizer components remaining in the pot medium, so as to avoid fertilizer damage harming the orchid plants.
Fourth, newly potted orchid plants must not be fertilized. Fertilization is only possible after orchid roots more than 3cm long have grown, otherwise the orchid will certainly die.
Fifth, do not water with fertilizer on low-temperature days below 10c°, high-temperature days above 30c°, or on rainy days with saturated humidity.
Sixth, the time for root-system fertilization is best in the evening. Fertilizing in the evening allows absorption overnight, and watering once more the next morning can avoid fertilizer damage. If fertilizing in the morning, the pot temperature rises under sunlight during the day, which very easily burns roots and damages seedlings.
Seventh, re-exported orchids must not receive root application of organic or inorganic fertilizers within one year.
Eighth, deodorize. All kinds of decomposed fertilizers have a foul smell. The orchid owner may be able to tolerate it, but it will affect the neighbors and cause conflicts. When growing orchids indoors, the foul smell lingers for a long time after application, so deodorization is needed. There are two deodorizing methods: first, decompose for a longer time, preferably more than one year; second, put a little fruit peel, especially orange peel, into the decomposition liquid, which can effectively remove the foul smell.

2. “Foliar fertilization” means spraying an organic or inorganic aqueous solution with nutritional effects onto orchid leaves at a certain dose and concentration to provide direct nourishment. Foliar fertilization has the advantages of small dosage, strong targeting, fast absorption, obvious effects and low cost, and is especially effective for rootless and few-rooted orchid plants.

Foliar fertilization should pay attention to the following points:
First, spraying must be targeted, that is, choose the corresponding fertilizer according to the nutrients the orchid plant needs at each growth stage and supply them in a targeted way. For example, during the new bud growth period, nitrogen fertilizer is mainly needed, and it must be combined with potassium fertilizer to be effective; when the new shoots mature, potassium fertilizer should be added to ensure the plant grows sturdily; during the flower bud differentiation period, phosphorus fertilizer should be supplemented; in addition, striped orchids should be sprayed with less nitrogen fertilizer to prevent excessive nitrogen, increased chlorophyll and degeneration of the stripes.
Second, mixing must be scientific. Although commercial foliar fertilizers have relatively complete nutrient components, do not always use the same variety; they should be mixed and used alternately to make up for each other's shortcomings and make the nutrition more comprehensive. For example, using urea as a foliar fertilizer easily causes excessive growth, so it must be mixed with monopotassium phosphate. Generally, acids and bases must not be mixed, and biological bacterial fertilizers must not be mixed with other fertilizers.
Third, the concentration ratio must be appropriate. The concentration used must strictly follow the relevant instructions; it is strictly forbidden to raise the concentration at will, otherwise it will backfire, cause fertilizer damage, and even inhibit orchid growth.
Fourth, the spraying time must be reasonable. Foliar fertilization should not be carried out in the morning. Generally, it is best in the evening on a sunny day when sunlight cannot reach the leaf surface and the leaves can dry within one hour after spraying. This on one hand helps the orchid leaves absorb nutrients at night, and on the other hand avoids fertilizer damage and reduced efficiency caused by light, especially preventing liquid accumulation in the leaf center from causing bud rot. In addition, the interval should not be too short; once about every ten days is best, so as to avoid hypernutrition.
Fifth, the spraying method must be particular. Because fertilizer must be absorbed into the plant through leaf stomata, and leaf stomata are mainly on the underside of the leaves, spraying should mainly reach the underside of the leaves. The nozzle should point upward, the mist droplets should be fine, and only then will there be more opportunity to spray the underside of the leaves. At the same time, the spray amount should not be too large; it is best if the leaves do not drip, so as to prevent fertilizer solution from accumulating at the leaf tips and causing fertilizer damage and tip burn.
Sixth, spray less during the dormant period. During the low-temperature dormant period, the physiological activity of orchid plants weakens and they generally do not absorb fertilizer. However, monopotassium phosphate, which improves cold resistance, and easily absorbed biological bacterial fertilizers can be sprayed once about every half month. At the same time, spraying a little foliar fertilizer on rootless and sickly weak orchid plants can maintain their life and increase the survival rate.
Seventh, be cautious about spraying growth hormones. Growth hormones do indeed do a good job of promoting plant growth and development, increasing the sprouting rate, promoting early maturity and increasing yield, but their main function is to promote cell elongation. After application, excessive growth and even lodging will occur, which has a clear impact on the health of orchid plants. It is better not to use them.
Eighth, foliar application depends on the weather. On rainy days the air humidity is high, water is hard to evaporate, and the fertilizer solution stays on the leaf surface for a long time, easily causing fertilizer damage. In high-temperature weather, especially in hot weather above 30c, water evaporates too quickly, which rapidly increases the concentration of the foliar fertilizer and causes fertilizer damage, so spraying is not suitable.
Ninth, wash the leaves after spraying. After fertilizing in the evening, spray water once the next morning to wash off the fertilizer remaining on the orchid leaves, so as to avoid fertilizer damage caused by sunlight.
Tenth, foliar application cannot replace root application. Foliar fertilization is an auxiliary means of fertilization and cannot completely replace root application; it can only make up for insufficient root absorption, otherwise it will cause root shrinkage and poor growth.

V. Points to note when fertilizing orchids. The technique of fertilizing orchids is both simple and complex. Usually the following points need attention:

First, different orchid species need different amounts of fertilizer. For example,Cymbidium faberineeds a large amount of fertilizer, whileCymbidium goeringiineeds a small amount of fertilizer, onlyCymbidium faberione fifth of that is enough.
Second, different cultivation substrates require different fertilizers. For example, hard materials such as volcanic stone and Xiandu soil contain no fertilizer components themselves, so more fertilizer should be applied; while using humus and the like as the medium, because it itself has fertilizer components, no more fertilizer is needed, so the fertilizer requirement is relatively small.
Third, different seedling conditions require different fertilization situations. Strong and large seedlings should be fertilized frequently and heavily, while old, weak and diseased young seedlings should be grown plainly and absolutely must not be fertilized, otherwise haste makes waste and death will certainly be accelerated.

Fourth. Multiple fertilizers should be used alternately. Using a single fertilizer makes it hard to ensure complete nutrient components. Generally speaking, alternating organic fertilizers, inorganic fertilizers and biological bacterial fertilizers is best.
Fifth, fertilize according to the roots. Short and thick roots indicate too much fertilizer; blackened roots indicate fertilizer damage has already occurred; long roots indicate insufficient fertilizer; many and fine roots indicate a serious fertilizer shortage.
Sixth, fertilize according to the leaves. For example, if orchid leaves are thin in texture and pale in color, it indicates a fertilizer shortage; if orchid leaves are thick in texture and green in color, it indicates no fertilizer shortage. After fertilization, if the leaf color becomes deep green, it indicates the fertilizer has taken effect; if the leaf color does not change, it indicates the fertilizer is too weak and the concentration should be increased.
Seventh, do not fertilize during the flowering period. Flower buds have a strong ability to absorb fertilizer components but a very weak tolerance. Once the flower buds emerge above the pot surface, fertilizing again will stimulate vegetative growth and inhibit reproductive growth, causing poor flower bud development, petals that do not spread open, and early flower withering. Fertilizing during the flowering period means the flowers will certainly fail.
Eighth, animal fertilizers and plant fertilizers must be fully fermented. Fresh fertilizer must not be applied; applying fresh fertilizer will certainly kill the orchid.
Ninth, pay attention to fertilizer damage. If the leaf color turns yellow and the leaf tips scorch after fertilization, it indicates too much or too concentrated fertilizer has been used. Immediately water heavily or repot and change the soil for emergency rescue, otherwise the orchid will certainly die.
Tenth, the three essential fertilizer elements must be scientifically combined. In the process of orchid growth and development, nitrogen, phosphorus and potassium are all essential nutrient elements. Applying only nitrogen fertilizer without phosphorus and potassium will not produce a very good effect either; the plant will grow excessively, the leaf texture will be soft, and it will be prone to pests and diseases. But favoring phosphorus and potassium fertilizers while lacking nitrogen fertilizer will make orchid plants grow short, with yellow-green, stiff, lusterless leaves, few new buds, and easy aging of the plant. Therefore the relationship among the three elements must be handled well, and no single fertilizer should be over-applied. It is only that nitrogen fertilizer should be a little more in the early growth stage of orchids, potassium fertilizer a little more in the middle growth stage, and phosphorus fertilizer a little more in the late growth stage.

Fertilizing orchids is a science and a field of learning, and one cannot do it without careful study, active exploration, careful pondering and deep research. As long as fertilization is done properly, the orchid plants will certainly grow sturdily, and it will also surely delight orchid growers and add endless pleasure, thereby truly achieving the goals of cultivating the mood and prolonging life.