Selection of Orchid Growing Medium
Completely analyzing the knowledge of orchids, the selection of orchid growing medium, let's get to know together next.
Principles
To grow orchids well, the first problem encountered is the selection of growing medium. To select a good growing medium, it is necessary to understand the growth characteristics of orchids.
People usually consider orchids (especially national orchids) as terrestrial plants, but strictly speaking, this is a misconception. Orchids should be considered as semi-epiphytic plants. The stomata on orchid leaves are sunken, and their respiratory function is not complete, depending on the roots for respiration; orchids mostly grow in places rich in humus and loose soil; the growing areas of orchids often have dry soil and high humidity, with orchid leaves absorbing moisture from the air to compensate for the insufficiency of the roots.
Therefore, when selecting orchid growing medium, we should pay attention to the following principles:
1. Loosely aerated. In the practice of growing orchids, we know that selecting granular medium instead of powdery medium is to create a loosely aerated environment for orchids, which is convenient for root respiration.
2. Moisturizing without waterlogging. Orchids are plants that need water, but their roots are succulent and do not tolerate waterlogging. Good medium allows water to flow immediately after watering, never accumulates water, and can remain moist for a long time.
3. Clean and fertile. Wild orchids have strong resistance, but their resistance decreases after transplantation, with more diseases and pests, and also require some fertilizers. The cleanliness and fertility of the medium are necessary conditions for the normal growth of orchids.
Classification
In the previous text, we described the basic growth characteristics of orchids and the basic principles of selecting growing medium, which opens up our thinking for selecting orchid growing medium.
Orchids are semi-epiphytic plants and have different requirements for the uniqueness of the medium compared to some terrestrial plants. Long-term artistic orchid practice has proven that there are many types of medium available for us to choose from. Based on the medium widely used and sold in the market, it can be roughly divided into the following three categories:
1. Soil materials. Mainly including mountain soil, pond soil, bamboo root soil, peat soil, and various humus soils, etc.
This type of medium is the main material of the traditional planting method. Its advantages are moisture retention, fertility, easy sourcing, and low cost. The disadvantages are that it easily compacts and accumulates water, does not dry easily after watering, and contains bacteria and is prone to pest infestation. (Currently sold Sichuan Xian soil and some人工-made granular soils are no longer traditional soil materials, to be discussed later.)
2. Organic materials. Mainly including bark, decayed wood, coconut bran, sawdust, sugarcane residue, peanut shells, snake wood, palm fibers, and mosses, etc.
The main advantages of this type of medium are moisture retention, breathability, and providing organic fertilizer for orchids after decay, which is beneficial for root growth. The disadvantages are that it is prone to pests and bacteria, especially during the decaying process, which can release heat and harmful substances, easily burning the orchid roots.
3. Hard medium materials. Mainly including pond stones, planting stones, volcanic stones, pumice, perlite, broken bricks, and ceramsite, etc.
The selection of this type of medium is the result of continuous exploration and reform in artistic orchid practice. Its advantages are that it is granular and not easy to break, clean and not prone to pests, good breathability and will not compact, and does not accumulate water. The disadvantages are that it is easy to dry and does not contain fertilizer; if the particle size is not selected properly, it will not be conducive to orchid root growth.
Selection
As mentioned above, the growth characteristics of orchids provide convenience for us to select orchid growing medium. However, orchids are living organisms that will live in the small environment we provide for a long time, and their growth will depend on whether we can provide a good environment and management. The selection of orchid growing medium is an important part of the orchid growing environment, so we must not be careless in selecting orchid growing medium. But faced with so many orchid growing mediums, how should we choose?
In history, our orchid ancestors, despite using only mountain soil to grow orchids, have made many explorations. For example, “Soil is the food of orchids, and the nature of each type of soil can be compared to rice. Fuyang soil is like Changshu rice, Yuanyao Guanzishan is like glutinous rice, Songjiang Beigan Mountain Tongzhou Army Mountain is like indica rice...”. Growers must fully understand the looseness, hardness, and softness of each type of soil and use them evenly, and there will be no mistakes. With the development of science, modern orchid enthusiasts have made even more extensive explorations in artistic orchid practice, and the selection of orchid growing medium is diverse. The practice of our ancestors and modern orchid enthusiasts has proven that as long as it meets the growth characteristics of orchids, any type of medium can grow orchids well. The key is that different mediums are suitable for different environments, different pots, and different management methods. Currently, there are three main schools of thought in the selection of main orchid growing mediums in China: the traditional soil medium method mainly in Yunnan, Guizhou, and Sichuan, the hard medium method mainly in Guangdong, Fujian, and Taiwan, and the mixed medium method mainly in Jiangsu, Zhejiang, and Shanghai. The following are the selection of mediums and precautions for these three methods.
I. Traditional Soil Medium Method.
As the name implies, this method selects soil medium materials and uses traditional cultivation methods to grow orchids. We have analyzed the advantages and disadvantages of this type of medium in the “Classification” section, so when selecting this type of medium to grow orchids, we should pay attention to the following points:
1. Whenever possible, use granular medium instead of powdery medium, the soil should not be too sticky, and if it is too sticky, a small amount of coarse sand or sawdust can be mixed into the soil to improve the soil texture and quality. The planting time should not be too long, and the pot must be repotted and the soil changed every year.
2. The pot should be selected with good breathability and an open mouth, such as a mud pot or sweating mud pot, and a water filtration layer must be placed at the bottom of the pot to prevent the soil from blocking the drainage holes and causing waterlogging.
3. In daily management, we should mainly adopt the principle of “dry cultivation,” that is, when watering, we must grasp the principle of “no watering when not dry, mainly moisturizing; better to be dry than too wet.” However, we should also prevent the phenomenon of “diamond shell dryness” that starts from the bottom of the pot and dries up.
4. Since the soil material we use contains a lot of humus, there is no need to add base fertilizer again. We can choose to fertilize by topdressing, and at the same time, we must do a good job of pest control and sterilization to prevent the invasion of diseases and pests.
5. The placement of orchids should be in a well-ventilated area, such as a courtyard or balcony, and the orchid pot can be elevated to keep it in a fully ventilated environment, with relatively lower humidity.
II. Hard Medium Method.
Using various hard mediums to grow orchids has been a popular cultivation method in China in the past decade. Compared to the traditional soil medium method, the biggest advantage of this method is that it facilitates our daily management and speeds up the growth of orchids. However, it also has very obvious shortcomings. Therefore, when selecting this type of medium to grow orchids, the following precautions should not be overlooked:
1. Since this type of medium is usually in various sizes of particles, when selecting, we generally choose large particles like broad beans and small particles like soybeans. Too large particles are not conducive to root growth, and too small particles are not conducive to drainage. When planting, more large particles can be used for thick roots, and more small particles can be used for thin roots.
2. In daily management, we can adopt the method of “wet cultivation” to grow orchids, that is, always keep the medium moist. However, we should still follow the principle of adopting different watering methods based on the different textures of the pots and the different strengths of the orchid seedlings, and never overwater.
3. This type of medium itself does not contain fertilizer, and artificial fertilization is required to ensure the normal growth of orchids. We should pay attention to applying different fertilizers according to different growth stages of orchids and combine topdressing and base fertilization. Base fertilizer should be selected with slow-release granular fertilizer, and topdressing should be done with the principle of “rare, thin, and frequent.”
4. This method is suitable for environments with high humidity and a breeze. Usually, orchids should be placed in enclosed or semi-enclosed places, such as orchid fields, orchid sheds, enclosed balconies, or indoors. Some snake wood chips or moss can be placed on the pot surface to keep the particles moist.
5. When using, we can mix a small amount of organic medium materials such as bark and coconut bran into this type of medium to improve its dryness defect and also provide some nutrients for the orchids.
III. Mixed Medium Method.
Since each type of medium has its own shortcomings, using a single medium to grow orchids not only requires certain environmental and conditional factors but also brings inconvenience to our management. The emergence and use of the mixed medium method can be said to be a significant progress in the history of orchid cultivation. This method is to mix several types of medium from soil, hard, and organic materials to create a new medium for growing orchids. Its biggest advantage is that during the preparation process, we can adjust the various mediums according to our own environment, pots, and management methods to meet the needs of orchid growth. Similarly, when using this type of medium, we need to pay attention to the following precautions:
1. Which mediums and in what proportion to choose depends on our environment and the pots used, and we can start by testing a few. Generally speaking, in an open or well-ventilated semi-enclosed environment, if we usually use pots with good breathability such as mud pots or sweating mud pots, we can use more soil and organic material mediums and less hard medium materials; if it is in a closed or semi-closed environment with high humidity, we can use more hard and organic material mediums and less soil medium materials.
2. Since this type of medium contains some nutrients, we can apply less or no base fertilizer and mainly use topdressing, doing so with the principle of “thin fertilizer and frequent application.”
3. When preparing this type of medium, the soil and organic material mediums we select may contain bacteria and pests, so we must use drugs or high temperatures for sterilization and pest control before preparation. At the same time, since organic material mediums easily produce heat and harmful substances during decomposition, we can solve this by soaking in water and then using high-temperature treatment in a microwave oven.
4. When preparing this type of medium, we often use some人工-made granular soil. This type of granular soil indeed has many advantages, but it also has many problems. Some use harmful adhesives for orchids, some cannot withstand water immersion, some contain salt and alkali components, and some have too much fertilizer... We should be cautious when selecting. After using, the “He Wang” brand Xian soil produced in Sichuan can be considered as the first choice for this type of granular soil, but it needs to be soaked for more than 24 hours before use.
The above sharing is the complete content on the selection of orchid growing medium (detailed). Have green plant enthusiasts understood?