Causes and prevention of rotten roots of orchids

In winter, orchids are in the dormant or slow growth stage, and the basin soil should be dry; spring and early summer are important periods for orchids to take root and draw leaves, and the basin soil should be moist; but if it is too wet for a long time, it is also easy to cause rotten roots, withering and yellow leaves, and even death. Due to excessive water, resulting in soil stagnant water, poor air permeability, resulting in insufficient oxygen, hindering root respiration, causing root blackening and decay. Magnolia must avoid its harm in plum rain or rainy season, because it is wet for a long time, black spots are most likely to occur on new leaves, and stamens often have "rotten clothes" phenomenon, affecting flowering and ornamental. However, if the basin soil is too dry, it is easy to make the pseudo-bulb dry or other tissues lose water and affect metabolism, which will also lead to tissue weakness and poor plant growth. The pot soil should be wet in autumn to facilitate the emergence of leaves and flowers in the coming year. Therefore, orchid farmers should know the secret of "not wet in winter, not dry in autumn". The above shows that orchids have different requirements for water in different periods, so the amount of water should be strictly controlled according to the requirements. At the same time, improper fertilization of orchids can also cause root rot, such as excessive fertilization, excessive concentration or pouring liquid fertilizer into the leaf sheath, which will have adverse effects on orchid peanuts. When fertilizing, we should increase or decrease the amount of fertilizer according to the amount of water, so as to make it grow harmoniously.

In order to cultivate a good orchid, it is necessary to cultivate the orchid root well, the root group develops vigorously, the root system is developed, and the absorption, transport, photosynthesis, respiration and energy storage and accumulation of water and nutrients can be carried out normally. the growth rate, reproductive ability and flowering rate will also be enhanced. Otherwise, the root system is not good or rotten, lost, water and nutrient absorption and transport are blocked, photosynthesis, respiration and other capacity is reduced, the orchid will gradually collapse and die. The rotten roots of orchids are mainly caused by the following two reasons: (1) the lack of filtration and ventilation function in the cultivation substrate water is the source of all things, and the growth of orchids must have water in order to absorb and transport nutrients and carry out normal metabolism. Orchid is a kind of air root plant. In the process of its growth, a small part of the water is supplied by moisture in the air, and most of the water must be absorbed by the water contained in the cultivated substrate. The orchid root also needs to absorb oxygen from the matrix pores in the orchid basin to breathe. If the drainage of the substrate in the orchid basin is poor and the water content is too high, the water will fill the matrix pores, resulting in stagnant water, the matrix pores are full of water and lack of oxygen, the roots are suffocated by hypoxia, and the root function is gradually lost for a long time, and at this time, the roots will rot because of the invasion and reproduction of harmful bacteria. (2) the water quality is unclean or the pH value of the water is not suitable. The water for orchids must be clean and unpolluted. If unclean water is used, some harmful bacteria or toxins will erode and pollute the roots of orchids, causing serious diseases of roots and stems and leaves, blackening and decay of roots and death of orchids. The PH value of orchid water must be between 5.5 and 6.5. if the PH value is less than 5, it belongs to acidity, which will restrict the orchid root to absorb nitrogen, phosphorus, potassium and other main elements. In the acidic environment, soil sexually transmitted bacteria such as root rot are the most suitable for growth and reproduction, endangering the root system to accelerate the rot and death of orchid roots, and the PH value above 8 is slightly alkaline, alkaline water and substrate will hinder the absorption of trace elements needed for the growth of orchid plants, and orchid roots and orchid plants will die gradually if they are not nourished by trace elements. In view of the above two problems, some corresponding measures need to be taken in the process of cultivation: (1) select and match the seed orchid substrate. The seed orchid matrix should be filtered and breathable, moist but not waterlogged, dry but not dry. At present, there are many special materials for orchid cultivation on the market, such as Emeishan soil in Sichuan, expansive soil in Chongzhou, and many kinds of orchid special soil in Guangdong, which are all very good materials for orchid cultivation. Some rotten leaf soil can also be added to these materials to supplement the lack of fertility. Can also use local materials, such as weathered soil, broken bricks, broken carbon particles, broken oak bark, etc., mixed with an appropriate amount of rotten leaf soil, the effect is also very good, not only can filter water breathable, but also moisturize and do not waterlogging, but also have a certain degree of fertility. However, it should be noted that the materials used must be non-toxic, sterile, pollution-free and free of parasitic eggs, otherwise it will also bring harm to the roots of orchids. (2) the water for watering orchids must be clean. Polluted water, unclean water can not be used. According to many orchid books, streams and rivers are the most suitable for orchids to grow, but most orchids live in cities and do not operate orchid gardens professionally, so it is difficult to do so. Watering orchids with tap water, the author from many years of experience, the effect is also very good, if possible, put the tap water in a bucket or basin for a few days, let the chlorine in the water volatilize that is even better. If the orchid is watered with spring water or pond water, we should pay attention to using PH value test paper to test the pH value of the base, PH value is less than 5, alkaline substances such as lime can be added to adjust, PH quality is more than 6.5, hydrochloric acid, acetic acid, citric acid and so on can be used to adjust. (3) No matter what texture of the orchid basin is used, there must be appropriate holes in the bottom of the basin, and it is better to have a few holes around the lower part of the basin wall. In short, it should be able to ventilate and filter water. When planting orchids, the lower part of the orchid basin can be covered with a layer of broken bricks or charcoal to facilitate drainage and ventilation. The placement of the orchid basin, to make the basin bottom and basin wall air circulation, if there are conditions, you can use orchid rack overhead orchid basin, so the effect is better. To develop a good orchid needs a suitable temperature, humidity, light and other environment, but to create a good environment for the orchid root is the most important link, to cultivate the orchid root, we can cultivate the ideal orchid.