Orchid Fertilization Methods and Fertilizer Selection Tips

March is the season of warm spring and blooming flowers. Temperatures generally rise noticeably at this time, with average sunny-day temperatures above 10°C (a few days ago there was an abnormal 25°C, which then dropped to minus 3°C). During this year's particularly low-temperature period, the flowering season of Cymbidium goeringii varieties has already approached its end. Most Cymbidium faberi are also in the large and small bud-stem elongation stage. As the farming proverb says: "At Awakening of Insects the trees revive, and when the hundred grasses sprout." Now that it is mid-March, orchid buds have already begun to grow faster (breaking dormancy), and thus they have started to increase absorption of various fertilizers. At this time, pots that did not receive base fertilizer when repotting and changing medium, or pots that were not repotted and had their medium changed, should be given supplementary base fertilizer so as to promptly supply the nutrients needed for orchids to sprout and root. At this time, fertilization methods are truly diverse, such as base fertilizer, top dressing, foliar spraying, and so on. In terms of fertilizer selection, everyone has their own preferences, such as: organic fertilizers, inorganic fertilizers, micro-fertilizers, bacterial fertilizers, hormone fertilizers, etc.

At this time, the author is no exception and buries "Zhixiang" and "Active Soil" 1 cm below the pot surface. The dosage is: for a 10 cm pot mouth, apply 3-5 granules of "Zhixiang", and apply a corresponding amount (3-5 granules) of "Active Soil" near the pseudobulbs; for a 15 cm pot mouth, apply 8-10 granules of "Zhixiang", with "Active Soil" applied correspondingly in the same way as above; for a 20 cm pot mouth, apply about 15 granules of "Zhixiang", with "Active Soil" applied correspondingly in the same way as above. The purpose of this additional base fertilizer application is for pots that have not been repotted; for pots that have been repotted, the above base fertilizer was already applied during the medium-changing operation. As for other fertilizers, they should be applied as top dressing when the orchids need them and are not uniformly considered for now, such as post-flowering rejuvenation fertilizer and bud-promoting fertilizer.

In view of this, the selection and application of several fertilizers will be discussed below:

I. Organic Fertilizers

Organic fertilizer is a full-element nutrient fertilizer, rich in organic matter and trace elements such as nitrogen, phosphorus, potassium, calcium, magnesium, iron, manganese, zinc, copper, sodium, aluminum, lithium, strontium, chlorine, ammonia, sulfur, boron, molybdenite, nitrates, salts, etc. There are no more than two sources of organic fertilizer. One is composted by orchid growers themselves; they collect poultry and livestock and aquatic animal organs (offcuts) and excrement, as well as plant stalks, for composting. The duration depends on circumstances, and some are only put into use after as long as several years. This is one of the ancient methods of making organic fertilizer. Due to varying degrees of pollution and unpleasant odors, the proportion made and used in this way is now greatly decreasing. The other is commercially produced organic fertilizer that is thoroughly sterilized and has little odor. This kind of fertilizer can fully replace the advantages of homemade organic fertilizer, so most indoor or balcony growers prefer commercial organic fertilizer. Currently available commercial organic fertilizers include: Zhixiang (solid), Xishuo (liquid), Gaocui (liquid), fish extract fertilizer (liquid), etc.

The characteristics of organic fertilizer are: slow absorption, long-lasting fertilizer effect, and comprehensive nutrition, so it is now commonly used during the post-flowering rejuvenation period.

II. Inorganic Fertilizers

Inorganic fertilizer is a chemical fertilizer that does not contain organic matter, such as: Huabao series, Haokangduo, Mofei, Duomiao, Aomiao, urea, superphosphate, ammonium carbonate, etc. Inorganic fertilizers are generally faster-acting and easily decomposed and absorbed, and it is best to use them alternately with organic fertilizers.

III. Micro-fertilizers

In addition to needing elements such as nitrogen, phosphorus, and potassium as nutrients, plants also need to absorb very small amounts of elements such as boron, arsenic, manganese, copper, cobalt, molybdenum, etc. as nutrients. These elements required in extremely small amounts are referred to here simply as micro-fertilizers. So-called deficiency symptoms are caused by insufficient trace elements. Supplementation with micro-fertilizers is generally mainly done by foliar spraying. In fact, most micro-fertilizers can be obtained from organic fertilizers; the lack of micro-fertilizers is a consequence of relying on inorganic fertilizers. Mixing soil granules (orchid fungus soil, Xiantu soil, peat soil, etc.) into the medium, together with the coordinated use of organic fertilizers, leaves no such lingering trouble, so there is no need to worry too much about whether micro-fertilizers are deficient or not.

IV. Bacterial Fertilizers

Bacterial fertilizer here specifically refers to a type of fungus symbiotic with orchids; it is now a synthetic biological preparation such as: Lanjunwang, etc. Spraying or watering application is also acceptable.

V. Hormone Fertilizers

The hormones mentioned here refer to cytokinins and the like applied to orchids, such as: various bud-promoting and root-promoting agents, Qianwang vitality essence, etc. Such fertilizers are generally used to increase yield. Spraying or watering application is sufficient, and in use it is not easy to become dependent on them.

VI. Gas Fertilizer

Gas fertilizer is a carbon disulfide gas. It is generally used on greenhouse vegetables; recently some people have been experimenting with its application on orchids. Its advantages are small dosage, low cost, and quick results.

In orchid cultivation, the principle of fertilization is to apply thin fertilizer frequently (the various fertilizers above are no exception). In the use of fertilizers, we encourage bold exploration; mastering the right measure will yield twice the result with half the effort. Growing orchids well is our common theme, and at the same time orchid growers are welcome to discuss this issue. Due to the author's limited level, please forgive any shortcomings!