What is the difference between dry-method orchid growing and wet-method orchid growing?

Orchids have been cultivated in China for more than 2,000 years, but due to historical reasons and the limitations of objective conditions, for a long time people have basically used the dry method to grow orchids. The advantages of this cultivation method are that materials are easy to obtain, operation is simple, management is easy, and it is close to the natural state. If cultivated properly, orchids grow well, with many flowers and fragrant blooms; but the disadvantages are also very obvious. That is, with the slightest carelessness, orchid roots can dry out, affecting orchid growth, or even killing the seedlings; in addition, due to insufficient water supply, orchid seedling production and growth are relatively slow, and the seedling production rate may even be seriously affected.

Therefore, the ancients said, “Understanding orchid growing is easy; watering takes ten years of skill.” For this reason, some orchid growers began to explore new orchid cultivation methods, and wet-method orchid growing emerged as the times required. Especially after the 1980s, with the increasing progress of orchid-growing techniques and the continuous improvement of orchid-growing media, combined with the successful experience of orchid growers in Japan, South Korea, Taiwan, China, and other places, wet-method orchid growing gradually became popular in our country and was valued and adopted by more and more orchid growers.

Of course, everything has two sides. Wet-method orchid growing also has its shortcomings, such as certain requirements for the choice of environment, the selection of pots, and the preparation of media. Management is relatively cumbersome, management costs are relatively high, greater effort is required, and it is easy to accelerate the decline of old seedlings. Also, the flowering quality of the flowers (such as fragrance and petal shape) is slightly inferior to that of traditional orchid-growing methods. Therefore, which orchid-growing method to choose cannot be generalized, and should be selected according to one's own actual situation.

Below is a brief introduction to the two orchid cultivation methods.

1. Dry-method orchid growing. Traditional orchid-growing methods all use dry-method orchid growing. This orchid-growing method does not have very strict environmental requirements. It can be used on balconies, under eaves, beside corridors, and under tree shade. Pots generally use clay pots, ceramic pots, wooden pots, plastic pots, etc., especially waist-drum-shaped clay pots and ceramic pots, which are ideal because of their good breathability and strong water absorption, making them very suitable for dry-method orchid growing. Orchid pots require drainage holes at the bottom and ventilation holes on the sides. If these requirements are not met, appropriate modifications can be made. The size of the pot can be determined by the size of the orchid plant. Absolutely avoid a small orchid in a large pot or a weak orchid in a large pot. The selection of media is the key to successful orchid cultivation. Generally, dry-method orchid growing mostly uses humus soil taken from deep mountain valleys where orchids grow, and then appropriately improves it by adding an appropriate amount of bark, granular burned soil, foam plastic granules, etc. This medium is rich in humus, slightly acidic, loose and breathable, and very suitable for orchid growth. A crucial part of dry-method orchid growing is water management.

Orchids have fleshy roots and no root hairs. They live symbiotically with orchid fungi and rely on orchid fungal hyphae to absorb nutrients to supply the needs of orchid growth. The orchid roots themselves are also important respiratory organs of the orchid and need to breathe oxygen. At the same time, orchid fungi are aerobic bacteria, and their growth and reproduction also require oxygen. Therefore, the medium must be breathable to ensure oxygen supply. If there is too much water, the oxygen content in the medium will be low, then orchid root respiration will be hindered, orchid fungi cannot grow normally, and hollow roots and rotten roots are likely to occur. Because dry-method orchid growing uses humus soil, although it has been appropriately treated, its water retention is still relatively strong, its permeability is relatively poor, and its nutrient content is relatively high. As the use time increases, the medium will become compacted and acidified and develop other adverse phenomena. If the timing of watering is not grasped properly, it is very easy to smother the orchid roots and affect orchid growth. The ancients emphasized, “Orchids like moisture but fear wetness; they like dryness but fear aridness.” Generally, a medium moisture content of 75—40% is most suitable. Below 40%, watering should be done; above 75%, over time, orchid roots are very easily damaged by waterlogging. But exactly when to water and when not to water depends on the environment, the medium used, the size of the pot, air temperature and humidity, and the strength of orchid growth. How can the amount of water in an orchid pot be judged?

Through exploration, orchid growers have roughly the following methods:

1.1 Intuitive judgment method. Judge according to the condition of the orchid leaves and the dry or wet condition of the orchid pot surface. If the orchid leaves show slight dehydration, the medium on the surface of the orchid pot has dried completely, and after digging about 5 cm into the surface medium it is still dry, this indicates that the medium no longer has enough moisture and watering should be done;

1.2 Weighing method. Its principle is to water the test medium thoroughly until no water drains out, at which point its moisture content is 100%; then dry the medium thoroughly, at which point its moisture content is about 20%; weigh them separately, and through calculation obtain the moisture content corresponding to each unit of weight, thereby judging the level of moisture content in the orchid pot medium. Theoretically, this method is relatively accurate, but in practical application there will also be some deviation, and it is not very easy to operate;

1.3 Stick insertion method. Carefully insert a bamboo stick into an appropriate position in the orchid pot, take it out after about one hour, and judge the amount of moisture in the orchid pot medium according to the degree of dampness of the bamboo stick. Now some people also use electronic moisture meters instead of a small bamboo stick. This method is relatively effective and relatively easy to master; its disadvantage is that it easily injures the orchid roots;

1.4 Pot tapping and sound listening method. Pick up a pot of orchids, place it by your ear, and lightly tap the edge of the orchid pot with your hand. If the sound is dull, it indicates that the medium still contains a lot of water. If the sound is crisp, it indicates that it is time to water. This method requires a certain amount of experience, and beginners are not easy to master it;

1.5 Comparison method. Put the same medium into an empty pot, then water it at the same time as the orchid pot and place them together. When checking, insert a finger into the comparison pot to inspect it, and the moisture content of the orchid pot medium can be compared. Of course, through years of exploration, some senior orchid growers also have their own set of methods for judging medium moisture. Generally, they only need a slight inspection to know the amount of moisture. This can be described as “having a bamboo in the chest” and is another matter. In short, dry-method orchid growing is a simple, convenient, practical, and economical orchid-growing method. It does not require too much effort and cost, and is especially suitable for orchid friends who do not have much time and have limited energy. As long as the watering problem is solved well, the orchids being grown can grow well, with abundant flowers and lush leaves, bright flower colors, and rich fragrance. It can be regarded as a relatively good mass-market orchid-growing method. 2. Wet-method orchid growing. Wet-method orchid growing was developed on the basis of summarizing the advantages and shortcomings of dry-method orchid growing. Its greatest feature is “wetness,” and its requirements for environment and medium are relatively higher.

2. When using wet-method orchid growing, attention should be paid to the following six points:

2.1 Orchid-growing environment. Compared with dry-method orchid growing, wet-method orchid growing has higher environmental requirements, especially the control of temperature and humidity must be appropriate. If temperature and humidity are too low, the significance of wet-method orchid growing is lost. Therefore, the orchid shed should preferably be fully enclosed or semi-enclosed, with good ventilation and lighting, and should avoid various pollution sources as much as possible, such as oil fumes and dust. Common methods for increasing humidity include: applying waterproof materials to the orchid shed foundation, laying red bricks, sand and gravel, volcanic stone slabs, and other building materials on the ground as a water-retaining layer, or placing water trays and building water pools, etc.; walls can use water curtain wall glass, volcanic stone slab curtain walls, spray humidification, etc.

2.2 Selection of pots. Clay pots, ceramic pots, wooden pots, and plastic pots are all ideal pots for growing orchids. Plastic pots especially, because they are cheap, lightweight, and durable, have recently become the mainstream pots for wet-method orchid growing.

2.3 Selection and preparation of media. The media selected for wet-method orchid growing are mainly coarse media, and their preparation should strive for “looseness and breathability, drainage and moisture retention.” The author's general mixing ratio is: 50% leaf mold, 15% granular bark, 15% granular burned soil, 10% foam plastic granules, 7% granular red soil, 3% snake wood. Of course, this formula is only for the media commonly used by orchid growers in Yunnan. If other media such as Xiantu are used for planting, it can be handled by reference. After the medium has been used for a period of time, it is prone to rotting or breaking into fine pieces, and should be replaced in time.