A brief discussion on the bottom material of orchid basin

When potted orchids are often padded with some materials at the bottom of the pot to facilitate drainage and ventilation. Can be used as the bottom of a variety of materials, commonly used are sand, cinder, broken bricks, foam blocks and so on. The properties of these bottom materials have their own advantages and disadvantages, some have more disadvantages than advantages, and some have fewer disadvantages than advantages. In many years of orchid cultivation practice, the author has tried these bottom materials. Let's talk about the properties of these bottom materials. Sand at the bottom of sand is a "traditional" usage. The sand used at the bottom should be pure river sand without salt or lime. River sand can be divided into thick and thin, and its particle size is inversely proportional to the strength of water retention. The advantages of river sand are as follows: stable physicochemical properties, cheap price, convenient sampling and good drainage performance of coarse sand. Its disadvantages: no microporosity, no nutrients, poor fertilizer preservation. Fine sand is used to cover the bottom because of its small particles, and it is common in practice that the drainage of the basin bottom is not smooth. The author uses "sand head" instead of coarse and fine river sand to cover the bottom, and its drainage permeability is more ideal. The so-called "sand head" is the sand leftover after the construction river sand is screened, and its particles are roughly between mung bean and soybean-like size. Coal cinder has the advantages of light weight, non-hardening, wide source, breathable and water-permeable, water and fertilizer conservation, mineral content, and because it is sterile and insect-free after high temperature burning, it is not easy to cause orchid plant diseases and insect pests, so it is often used as the bottom material of orchid basin. However, the cinder contains less fertilizer and is easy to be broken by extrusion, so as to reduce the effect of drainage and air permeability, so that the cinder at the bottom often forms a long wet and difficult-to-dry state. After repeated comparison and test, it is proved that cinder as the bottom material is not an ideal choice. Broken bricks have a wide range of sources, easy to take materials, easy to process, can be reused, good water absorption and drainage and air permeability, so it is a good bottom material. However, the weight of broken bricks is heavy, does not contain nutrients, and the performance of fertilizer conservation is also poor. After the brick is broken and processed, it generally has edges and corners and is easy to cut the orchid root. The broken brick particles used at the bottom should not be too small and should be processed into broad bean-sized bricks for better drainage and ventilation. The foam block is used as the bottom of the foam block, and the effect is good. It is a good material widely used as the bottom of the orchid basin in recent years. The foam block has many excellent properties, such as light weight, diuresis, breathability, warmth, no pressure on the root (the root can penetrate the foam block), the smell of deworming and disease prevention, easy separation from the old basin and so on. With styrofoam block at the bottom, the orchid plant is not easy to rot root, high germination rate, white and long root, easy to produce leaf art. The deficiency of Styrofoam block is the lack of organic fertilizer, which can be improved by fertilization. Practice has proved that the foam blocks used at the bottom should be processed into small pieces half an inch square, too small, too big is not good. The blue basin is filled into the bottom material, and its main function is to facilitate the discharge of water and air circulation. However, some factors will reduce the role of these two aspects, and measures must be taken to overcome them. Measure 1: when planting orchids, the method of shaking orchid pots or beating the periphery of orchid pots is often used to make the potted soil close to the orchid root. If the plant material used is dry, the fine plant material in the middle and upper part of the orchid basin is easy to sink to the bottom of the orchid basin pad with the wobble of the orchid basin, resulting in a smaller original gap between the bottom materials and reducing the effect of drainage and air permeability. It can be replaced by "finger pressure method", but it should not be under heavy pressure to avoid crushing and injuring Langen. Or the dry plants to be used will be sprayed into a slightly wet state with water, which can also achieve the effect of reducing the subsidence of fine plants. Measure 2: when the orchid is watered, the fine plants in the upper and middle parts of the orchid basin will sink to the bottom of the basin due to the gravity of watering. The plastic screen can be covered on the top of the bottom material to prevent the fine plant from sinking. According to observation, when Langen extends to the plastic screen, it will pass through the mesh and squeeze the yarn of the mesh around, which will not affect the extended growth of Langen. The screen should be made of plastic rather than metal. (Zhang Bingfu, Longyan, Fujian Province) correspondence address: Dongxiao Federation of overseas Chinese, Longyan City, Fujian Province Postal Code: 364012