What fertilizer do potted orchids need? How do you fertilize orchids?
Orchids originally grow in deep mountain valleys and forests, where they have a suitable natural environment, loose humus-rich soil, and soil with sufficient fertilizer and comprehensive nutrients, so they can grow very robustly. But after coming down from the mountain to a courtyard or balcony, because the environment has changed greatly and nutrients are not as plentiful as they were on the mountain, even well-grown orchids are unlikely to be as thick and strong as wild-collected orchids, so we should try our best to create a suitable environment and good growing soil for orchids.
Many people now use hard potting media (Sundat, Kanuma stone, expanded clay pellets) for planting, including my own orchid-growing medium. The fertilizer content in the medium can hardly meet the needs of orchid growth. If fertilizer is not applied at the right time according to the orchid's growth cycle, the orchid plants will produce few shoots, grow slowly, and recover strength slowly, with flowering and flower appreciation far off in the future. Therefore, timely fertilization is absolutely necessary. But you should understand and grasp when to fertilize, the fertilizer concentration, what kind of fertilizer to apply at different growth stages, and the preferences of different orchids for fertilizer. This point is very important.
Fertilization is a double-edged sword: one side is nutrition, the other side is harm. At a suitable concentration, it is a nutrient element that can make orchids grow vigorously, but if it is too concentrated, it becomes poison, causing orchid plants to collapse, become stunted, suffer root rot, or even be completely wiped out. My orchid-growing medium is Kanuma stone plus Sundat. Below I introduce my understanding of different fertilizer elements and how to fertilize.
1. Fertilizer elements
There are 16 essential nutrient elements for orchids. Apart from carbon, hydrogen, and oxygen, which are absorbed from the air, the rest all need to be supplied through fertilization to varying degrees to meet the needs of normal orchid growth. According to how much orchids need them, they are divided into macronutrient fertilizers, including nitrogen, phosphorus, and potassium fertilizers; secondary nutrient fertilizers, including calcium, magnesium, and sulfur fertilizers; micronutrient fertilizers, including chlorine, zinc, boron, manganese, molybdenum, iron, and copper fertilizers; in addition, there are some beneficial element fertilizers such as silicon-containing fertilizers and rare earth fertilizers.
1. Nitrogen fertilizer: Nitrogen is the main element that makes up proteins, and proteins are the basic substances in the composition of cell protoplasm. Applying nitrogen fertilizer can promote the formation of proteins and chlorophyll, making leaf color dark green, increasing leaf area, promoting carbon assimilation, and helping increase yield and improve quality.
2. Phosphorus fertilizer: Phosphorus is an indispensable element for forming cell nuclear proteins, lecithin, and so on. Phosphorus can accelerate cell division, speed up the growth of roots and aboveground parts, and promote flower bud differentiation.
3. Potassium fertilizer: The nutritional effect of potassium can increase the intensity of photosynthesis, promote the formation of starch and sugar in the plant, enhance the plant's stress resistance and disease resistance, and also improve the plant's absorption and utilization of nitrogen.
4. Magnesium: One of the elements that make up chlorophyll, promoting the process of photophosphorylation.
5. Calcium: One of the main raw materials for building cell walls.
6. Sulfur: A necessary component of certain amino acids.
7. Chlorine: It carries out certain physiological functions, such as participating in photosynthesis, regulating cell osmotic pressure, and maintaining ion balance in the body.
8. Iron: One of the elements that make up chlorophyll. It participates in metabolic processes such as photosynthesis and respiration, and is also one of the components of nitrogenase.
9. Zinc: It is an essential element for synthesizing tryptophan, and tryptophan is the precursor of indoleacetic acid.
10. Copper: One of the raw materials for synthesizing chloroplast proteins.
11. Boron: It plays an important role in physiological and biochemical processes. It participates in protein metabolism; participates in the formation of pectin, and when a plant lacks boron, pectin decreases; boron participates in the micronutrients necessary for vascular bundle development, the formation of lignin, and so on.
12. Molybdenum: It plays a certain role in plant metabolism and respiration. Molybdenum is also related to plant phosphorus metabolism. When molybdenum is deficient, it is not conducive to the conversion of inorganic phosphorus into organic phosphorus. In addition, molybdenum can also improve a plant's ability to resist diseases.
The above are the elements needed for orchid growth. Everyone is relatively familiar with nitrogen, phosphorus, and potassium fertilizers, while micronutrient fertilizers may be unfamiliar.
2. Fertilizers I use
(1) Fertilizer: I like Magic Fertilizer. Magic Fertilizer is a nitrogen-phosphorus-potassium-magnesium compound fertilizer. It is a slow-release fertilizer that releases according to the fertilizer concentration in the soil. It does not harm roots or buds. It does not matter if Magic Fertilizer touches roots or new buds. It has a significant effect on strengthening pseudobulbs and promoting flowering. I have used it for many years and put in quite a lot, about 20-30 granules per pot.
(2) Quick-acting compound fertilizer: The Hyponex usually used is a nitrogen-phosphorus-potassium compound fertilizer. According to the different ratios of nitrogen, phosphorus, and potassium needed during the orchid growth period, Hyponex is divided into No. 1-5. Different Hyponex types can be applied according to different growth periods. Hyponex is effective, but it does not dissolve easily. When using it, the undissolved parts should be thoroughly filtered out, so that undissolved granules do not burn new buds and cause plant collapse. I only use Hyponex No. 4. The nitrogen-phosphorus-potassium ratio of Hyponex No. 4 is 25:5:20. Its aqueous solution is purple. It has special effects of strengthening roots, stems, and leaves, promoting more offshoots and root clusters, and strengthening the stem. The concentration I use is 3000-4000 times, very dilute, generally applied once every 10 days. After the Spring Festival, the temperature rises and all things revive, so it can be applied after March. Hyponex No. 4's bud-promoting effect is still decent, promoting more root clusters, and its effect on strengthening pseudobulbs is also not bad. Hyponex No. 5: nitrogen-phosphorus-potassium ratio: 30-10-10, promotes the rapid growth of various seedlings, and the high-nitrogen formula promotes the rapid early growth of new shoots of Chinese cymbidiums. Hyponex No. 5 is used less. It can be used after the orchid buds open. For foliar spraying and root drenching, the high-nitrogen formula makes new seedlings grow rapidly, and the orchid plants become tender green, wide, and thick. Hyponex No. 3: nitrogen-phosphorus-potassium ratio is 10:30:20, with a particularly high phosphorus content. Its aqueous solution is grayish black. It mainly promotes orchid flowering. Fish essence fertilizer: organic fertilizer, high-phosphorus fertilizer, promotes flowering.
(3) Biological bacterial fertilizer: Zhiquan and Xishuo contain not only nitrogen, phosphorus, and potassium, but also relatively comprehensive trace elements, live beneficial bacteria, and so on.
3. How to fertilize
① Fertilization form: Use Magic Fertilizer as base fertilizer, placed in the upper part of the pot. For topdressing, apply foliar fertilizer and root drenching at the same time, not foliar fertilizer alone.
② Fertilization methods:
1. Fertilize according to the orchid's growth period: After spring, all things begin to revive, and orchids also begin a new round of growth. At this time, apply fertilizer that promotes the differentiation of leaf buds, such as Hyponex No. 4 at about 3000 times and Zhiquan at about 2000 times, once a week. After buds emerge from the soil, the nutrition needed is mainly nitrogen fertilizer. I still mainly apply Hyponex No. 4, and in addition can apply Hyponex No. 5, Liweilv, and other fertilizers a few times less often. This season is the season when flower buds form. Many of my orchids have already produced flower buds. If they have not yet produced flower buds, on the basis of withholding water, apply phosphorus-potassium fertilizer, such as fish essence fertilizer or Hyponex No. 3, monopotassium phosphate, and so on. If the plants are strong, they should produce flower buds. Orchids grown at home at the same time may be in different growth periods, so different fertilizers should be applied according to different periods. In the hot midsummer, if there is no cooling measure, fertilization should be stopped. In winter, orchids are in a dormant period, so fertilization should be stopped. Orchid fertilization should use dilute fertilizer applied frequently.
2. Fertilize according to the orchid's growth condition: If the orchid is growing well and has good roots, fertilize normally; if the orchid is not growing well and has poor roots, fertilize less, and after the roots recover, fertilize normally again.
3. Use according to orchid variety: I mainly grow spring orchids and Huilan. Huilan has long, wide leaves and thick, strong roots, so it can be fertilized a little more. Spring orchids should be fertilized less than Huilan.
4. Relationship between fertilization and watering: When the medium is on the dry side, fertilize before watering. The fertilizer concentration must be dilute. After fertilizing, water again, and water heavily, to wash away the fertilizer inside the buds and the medium.
5. Relationship between fertilization and sterilization: Fertilization and sterilization can be carried out at the same time. Most fungicides and bactericides can be mixed with fertilizers. Read the instructions before use, but do not mix them with biological bacterial fertilizer. After using a sterilizing agent, biological bacterial fertilizer can be applied to replenish live beneficial bacteria.
6. When dividing plants, soak the orchid plants in about 500 times Zhiquan for 30 minutes. This can promote earlier rooting and sprouting.
4. Essential tools for fertilization
The fertilizer concentration must be accurate. Hyponex includes a small spoon, and one small spoon is 1 gram. Use a measuring bucket to measure the water.
For liquid fertilizer, use medical syringes to measure accurately. Medical syringes should be prepared in 5 ml and 1 ml sizes.