High-yield orchid cultivation techniques and watering methods in hot weather

Water is the source of life for orchids and the foundation of orchid growth. Watering orchids is the most important part of orchid cultivation and management. The ancients said: "Understanding orchid growing takes one lesson, but mastering watering takes three years of skill." This saying is quite reasonable; it shows that watering orchids is a profound discipline that can only be mastered through long-term practice and exploration. The accumulated practical experience of predecessors and the explorations of modern science have provided us with a shortcut, and their understanding of orchid watering is well worth studying, pondering, and researching.

I. Water is the source of life for orchids

First, water is an important component of orchid plant protoplasm. The water content of orchid protoplasm is generally above 80%. If the water content decreases, life activities are affected. If the protoplasm loses too much water, it will cause the protoplasm to break down, leading to plant death.

Second, water is a raw material in the metabolic processes of orchid plants. The assimilation and dissimilation processes within orchid plants all require the participation of water molecules, such as photosynthesis, respiration, and hydrolysis reactions.

Third, water is the medium for the metabolic processes of orchid plants. Nutrient elements in the growing medium can only be absorbed by orchid roots after dissolving in water, and various metabolic products must also be transported with water to all parts of the orchid plant.

Fourth, water enables orchid plants to maintain their inherent form. Only when orchid cells contain a large amount of water can the cells expand and the plant stand upright, facilitating the reception of light and gas exchange. Once an orchid plant loses water, it will wilt.

Fifth, water can regulate the body temperature of orchid plants. Water has a high heat of vaporization and specific heat, as well as high thermal conductivity, which helps orchid plants maintain body temperature and dissipate heat. One of the important functions of watering orchids is to regulate the body temperature of orchid plants.

In summary, water is the source of life for orchids and the foundation of orchid growth. Properly meeting the water needs of orchid plants is the most important condition for orchid growth.

II. Two pathways for supplying water to orchid plants

There are two pathways for supplying the water needed by orchid plants: one is absorption of water from the growing medium by the roots, which is transported throughout the plant through vascular tissue; the other is absorption of moisture from the air by orchid leaves to meet the metabolic needs of the orchid plant. Understanding this principle means knowing how to supply water to orchid plants.

III. Methods of watering orchid plants

The methods for supplying water to orchid roots are: pouring, sprinkling (showering), and soaking. "Pouring" means using a watering can to pour water along the edge of the pot. The advantage of this method is that water will not pour into the leaf center; the disadvantage is that watering is slow and difficult to soak through, requiring repeated pouring multiple times to achieve thorough soaking. "Sprinkling" means using a spray bottle or shower head to sprinkle water, wetting the entire orchid-growing environment, letting water seep from the soil surface to the orchid roots and moistening the orchid pot. The advantage of this method is that water can soak through the entire orchid pot; the disadvantage is that water easily splashes into the leaf center, so it must be used carefully, otherwise it will cause crown rot. "Soaking" means immersing three-quarters of the orchid pot together with the growing medium into water. The advantage is that water can soak through; the disadvantages are that it easily spreads bacteria and is labor-intensive and time-consuming. Expert orchid growers often combine these three methods, achieving very ideal results.

The methods for supplying water to orchid leaves are: misting and humidifying. "Misting" means using a sprayer to spray fine mist that falls directly onto orchid leaves, allowing the leaves to absorb it through their stomata. "Humidifying" means increasing air humidity for the leaves to absorb. There are also several humidifying methods: first, using a humidifier to create fine mist and increase spatial humidity; second, increasing water surface area by placing more water basins under the orchid shelf, relying on water evaporation to increase spatial humidity; third, artificially simulating rainfall to splash up water mist and increase air humidity; in addition, some use oxygen pumps placed in water basins to help volatilize water vapor, and so on.

IV. Water quality for watering orchid plants

Wild orchids grow on rainwater, so water used for cultivating orchids should be natural and pure, preferably clean and slightly acidic (pH value around 5.5). Generally, rainwater is best, river water is excellent, tap water is next, and well water should not be used. "Rainwater" contains many and comprehensive fertilizer components, among which spring rain is especially good, thunderstorm rain is relatively good, autumn rain is next, artificial rain should be avoided, and acid rain is harmful. "River water and pond water" are formed from collected rainwater and are beneficial to orchids, but river water polluted by industrial wastewater must not be used. "Tap water," if drawn from underground, must not be used; if drawn from rivers, its essence is still rainwater, but after processing by the water plant, there are disinfectant and clarifying agents present, which are harmful to orchids and cannot be applied directly. There are two solutions: first, fill several vats with tap water, expose them outdoors to the sun, store for many days, and rotate their use; second, add a small amount of fruit peel such as orange peel or apple peel, store for one or two days before use, which is effective in changing the quality of tap water. "Well water" belongs to groundwater: first, its temperature is low, and sudden irrigation is unfavorable for orchid growth; second, it is alkaline, and well water contains relatively more calcium and magnesium salts, so frequent irrigation is harmful to orchids.

V. Timing of watering orchid plants

Orchids "love moisture but fear wetness, love dryness but fear aridity." This saying of the ancients is quite scientifically sound. "Wet," "moist," "dry," and "arid" represent different degrees. Excessive moisture means wetness; "wetness" means too much water, which will suffocate orchid roots and cause them to rot and die. Excessive dryness means aridity; "aridity" means too little water, which will cause orchid plants to wilt, stunt their growth, and even dry up and die. "Dry" and "moist" represent moderate water levels, which is the state that orchids love for growth. To understand the key issues of "dry" and "moist," one must carefully observe and experience in practice, gradually accumulating experience to truly master it. There is no shortcut; it requires no less than "three years of skill." Generally speaking, when the growing medium on the pot surface is dry but not arid, and the drainage hole at the bottom of the pot is moist but not wet, this is the best time to water orchid plants. There is no need to wait until the potting soil is completely dry before watering, otherwise it will have adverse effects on orchid growth and development.

VI. Watering orchid plants must be based on natural factors

Watering orchid plants must be based on various natural factors that affect transpiration, such as humidity, temperature, light, wind, season, and weather, so as to make different water management measures.

First, look at humidity. If air humidity is low and transpiration is strong, water more; conversely, if air humidity is high or even saturated and transpiration has nearly stopped, water less or not at all.

Second, look at temperature. When air temperature is high, transpiration accelerates, water demand is greater, and watering frequency should increase accordingly; conversely, when temperature is low, water molecule activity is slow, diffusion is weak, and water demand is less.

Third, look at light. Strong light accelerates transpiration and the diffusion of water molecules, increasing water demand; conversely, water demand is less. Therefore, different light conditions and different shading levels require different water management: water more for those receiving sun, water less for those in shade.

Fourth, look at wind. Strong wind causes faster water evaporation; weak wind causes slower water evaporation. Dry southwest winds enhance evaporation, while moist southeast winds relatively weaken transpiration. Orchid pots placed in wind openings receive more wind and evaporate water faster; orchid pots in sheltered areas receive less wind and evaporate water more slowly.

Fifth, look at the season. Different seasons have different temperatures, humidity, and light, and the transpiration of orchid plants varies greatly. Water more in the hot, dry summer; water less or not at all during the plum rain season; do not water in the cold, overcast winter; water less in the low-temperature early spring; water more during the mild late spring when sprouting occurs; water more in the dry autumn.

Sixth, look at the weather. Weather in nature is ever-changing, and different weather conditions have different light, temperature, and humidity, so the transpiration of orchid plants varies greatly. The basic approach is: water more on sunny days, water less on cloudy days, do not water much when rain is imminent, and do not water on rainy (or snowy) days.

Accordingly, it is difficult to have an accurate and uniform management method for watering orchid plants. The saying "water once every few days" lacks scientific basis.

VII. Watering orchid plants must be based on the condition of the orchids

The general principle for watering orchids is "do not water when not dry; when watering, soak thoroughly." However, daily management situations are complex and must be analyzed and handled according to the specific conditions of the orchids.

First, it depends on the growth stage of the orchid. Orchids should be watered more during the growing period or bud differentiation period, watered less or not at all during dormancy, watered more during the sprouting period, watered less after sprouting, watered more when flower buds appear, watered less during the flowering period to prolong the flowering period, and watering should be stopped for several days after flowers fade to let them rest before watering again.

Second, it depends on the growth condition of the orchid. Water more for strong-growing orchids, water less for weaker ones, do not water diseased plants, water less or not at all for orchids needing rescue, water more when there are many plants in the pot, and water less when there are few.

Third, it depends on the moisture retention of the growing medium. Media with fine particles and strong water retention (such as mountain soil and wood chips) consume water slowly and require reduced watering frequency; conversely, media with coarser particles and weak water retention (such as Senju soil) require increased watering frequency.

Fourth, look at the texture and size of the pot. Water more for highly breathable clay pots, water less for less breathable purple clay pots and plastic pots. Small pots dry easily, large pots dry slowly, and watering frequency also differs.

In general, watering orchids requires handling according to specific circumstances and should not be simplified uniformly.

VIII. Time of day for watering orchid plants

Watering orchid plants also has a certain scientific basis in terms of timing. Generally speaking, watering in the morning is best. Generally, when orchids are outdoors in late spring and summer-autumn, morning watering is appropriate: first, after a night of cooling, the medium temperature in the pot is lower in the morning, and watering at this time will not harm the plants; second, watering thoroughly in the morning allows the medium to become moist by evening, with no standing water in the pot at night, and air circulation in the pot is good for orchid root respiration and circulation, which is beneficial to orchid growth; third, if watering in the evening, water evaporates slowly at night and easily causes standing water, while during the day when transpiration is fast, the pot has already become moist, creating a situation of "standing water in the pot when it should be dry, and lack of water in the pot when it should be moist"; fourth, in the evening the orchid pot temperature is still high, and suddenly watering with cold water causes a sudden temperature drop that affects root water absorption and disturbs physiological balance; fifth, at night the temperature is low, orchid cell activity is weak, and excessive water will cause bacteria to multiply and also breed snails and slugs. When orchids are indoors in winter and early spring, the watering time should be appropriately delayed, and watering around 9 o'clock after the morning temperature rises or at noon is best.

Regarding watering timing, the overall principle to grasp is: watering orchids in the morning is best; water a little earlier when the temperature is high, and a little later when the temperature is low.

IX. Amount of water for orchid plants

"When watering, soak thoroughly" is a standard for measuring how much water to give orchids. What is "soaking thoroughly"? The standard for "soaking thoroughly" is not only that water flows out from the bottom hole of the pot, but also that all the growing medium in the pot is thoroughly wet. Often, after one watering, although water flows from the bottom hole, the "thorough" standard is still not reached. To thoroughly wet the medium in the pot, one can water in several sessions or use the soaking method. For dry granular media, thorough soaking cannot be achieved without the soaking method, but the soaking method should not be used continuously; there must be intervals to let the orchids breathe. In addition, in winter and early spring, the amount of water used should not be too large; moist is better.

X. Several points to note when watering orchid plants

There are also many points to note when watering orchids:

First, pay attention to water temperature. Do not use cold water for irrigation in winter; water temperature should be close to room temperature, preferably 8-10°C. Do not use hot water for irrigation in summer. If using a water tower to store water, beware of water temperature being too high and damaging orchid plants and roots; water temperature must not exceed 25-28°C, and do not suddenly irrigate with cold water, to avoid damaging orchid plants.

Second, pay attention to humidity. When air humidity is too high, reaching 90-100%, never water or mist; daytime humidity of 70-90 is suitable. Too much humidity will weaken the roots' ability to absorb water, affect the number of new roots, and cause orchid plants to lose their driving force.

Third, pay attention to protecting new shoots. During the period when new shoots are splitting, root watering is appropriate; minimize sprinkling and misting, otherwise water pouring into the leaf center causes standing water and rot, resulting in losses.

Fourth, pay attention not to water only halfway. Some people mistakenly believe that orchids cannot be watered much, so they dare not water, often giving half-waterings, causing the medium to remain wet on top and dry below for a long time, resulting in root drying and withering due to lack of water.

Fifth, pay attention to reducing the use of standing water. If using a water tower to store water, standing for too long causes water molecules to form chain structures; the longer the time, the harder they are to break apart, making it difficult for them to participate in metabolic activities and unfavorable for absorption by orchid plants.

Sixth, pay attention to watering with "revival water." After fertilizing in the evening, orchid plants absorb most of the nutrients effectively through a night of absorption, and at this time they most need water, just as people need tea after a meal. Therefore, the next morning "revival water" should be given. It has two functions: first, to wash off fertilizer solution splashed on the leaves; second, to wash away residual fertilizer in the pot to prevent fertilizer damage.

Seventh, pay attention not to water too frequently. Orchids have a great tolerance for water and are relatively drought-tolerant plants; being a little dry has little effect. On the contrary, being wet is not acceptable; standing water for 24 hours will cause suffocation. In daily cultivation, the vast majority of people love orchids too much and water too frequently, causing root rot and even plant death.

Eighth, pay attention to "acid rain." If using rainwater, there are two types that cannot be used: first, acid rainwater cannot be used to water orchids. So-called "acid rain" is formed when sulfides, fluorides, and other acidic substances suspended in the air fall with rainfall; this water must never be used to water orchids. Second, water from artificial rainfall cannot be used; rain-seeding shells contain chemical substances that dissolve in rainwater, and using this to water orchids will also corrode orchid roots.

Ninth, pay attention not to spray water arbitrarily. "Misting" is necessary; besides supplementing water, it can also keep orchid leaves fresh and is beneficial for leaf respiration and photosynthesis. However, water should not be sprayed arbitrarily: do not spray under strong direct sunlight; do not spray in high-temperature weather; spray less when there is no wind and drying is difficult; do not spray water containing impurities; do not spray when humidity is too high on rainy days, and so on.