How to grow Acorus calamus (sweet flag) for medicinal use? Soil and water culture methods and solutions for yellow leaves

Acorus calamus is also called white calamus and Tibetan calamus. It grows on marshland, by streams or beside paddy fields. It is a sacred herb in traditional Chinese culture that can ward off epidemics and evil spirits. During the Dragon Boat Festival, there is a custom of tying calamus leaves together with mugwort and hanging them under the eaves. Therefore, more and more people are starting to grow calamus, so how do you grow calamus in soil? Can it be grown in water? What should you do if the leaves turn yellow?

1. How do you grow calamus?

1. Propagation method

When growing calamus normally, you must understand its propagation method. It can be propagated by division. This propagation method should be carried out from September to October each year. When propagating, you can take out the large plants, remove the withered and yellow old leaves, then divide the plant into several parts, plant the small offsets in flower pots and water them thoroughly.

2. Soil

Calamus is a moisture-loving plant that grows by the water. When growing it at home, you must choose a culture soil with good drainage and keep the potting soil moist. In addition, this plant has very strong vitality and grows quickly. During cultivation, it needs to be repotted in time. Repotting once a year is most suitable, and the repotting time should be in spring each year.

3. Fertilization method

Calamus has strong adaptability during the growing season and can be managed extensively. Calamus likes nitrogen fertilizer. Fermented soybean cake water is the best fertilizer, as it can avoid burning the seedlings. Nitrogen fertilizer can promote its growth. In the later stage, 2-3 topdressings are needed, combined with weeding. In the early growth stage of calamus, nitrogen fertilizer should be the main fertilizer. Before heading and flowering, increase the application of phosphorus and potassium fertilizers to enhance the immunity of calamus. Note that each time you fertilize, you must bury the fertilizer about 5 cm below the soil surface, and be careful not to place it too close to the roots to avoid burning them. Before overwintering, clean up the dead branches and fallen leaves on the aboveground part, and remove the pathogens and insect sources of pests and diseases.

4. Propagation method

Sowing

Clean the collected mature red berries, sow them indoors in autumn, keep the soil moist or in shallow water, and at around 20°C, they will gradually germinate in early spring. Then carry out separate cultivation. When the seedlings grow strong, they can be transplanted and planted out.

Division

In early spring (around Qingming) or during the growing season, dig out the underground stems with a shovel, wash them clean, remove the old roots, stems and dead leaves and stems, then use a sharp knife to cut the underground stems into several pieces, keeping 3-4 new buds on each piece for propagation. For division during the growing season, dig up the plant with roots, wash it clean, remove 2/3 of the roots, then divide it into pieces. When dividing, keep the tender leaves, buds and new roots intact.

2. Can calamus be grown in water?

This plant is essentially shade-loving and moisture-loving. From this point of view, water culture is even better than soil planting. Indoor ornamental cultivation is mostly by water culture. As long as the clean water does not dry up, its lifespan can reach several decades.

Water culture method

Calamus with large old roots is suitable as the target material for water culture. The best ones are those whose old roots rise above the mud surface and wind like a dragon. Small scattered calamus plantlets can be gathered into a ball, wrapped with palm fiber and placed in a water basin. However, small calamus plantlets have very short fibrous roots, so enameled wire can be used to string these calamus plants into a ball. Note that you must not damage their old roots, then wrap the enameled wire around them several times.

When planting, you can choose a medium-depth watertight container according to personal preference and plant size. Wash the calamus stem sections, trim off old roots and overly long roots, first soak them in potassium permanganate solution for 2 hours to disinfect, fill one side with pebbles to fix the plant in the pot, keep the water level just above the roots, do not soak the leaves, and finally place it in a place with sufficient light, but do not expose it to direct sunlight.

3. What should you do if the calamus leaves turn yellow?

1. Water-yellow

Water-yellow: calamus likes water, and generally watering does not affect its growth. However, if the calamus pot has no drainage hole, or the growing medium is not permeable, water accumulates in the pot and causes waterlogging, resulting in soil oxygen deficiency, then the calamus roots rot and the leaves turn yellow. In addition, in the south, during the returning damp days and plum rain days, you should also pay attention. In such weather, with continuous rain and extremely high air humidity, transpiration is reduced, and calamus is also prone to yellow leaves. When encountering water-yellow, first reduce the watering frequency and amount, place the calamus in a ventilated place, and if it is a problem with the pot or growing medium, replace them as soon as possible.

2. Drought-yellow

Generally, when we grow calamus for beauty, we mostly use small pots, with little space and little growing medium. If the weather is sunny and hot, drought problems will appear if it is not watered for two or three days. For calamus, this is fatal, and it will immediately show you a yellow face. For drought-yellow, first water as soon as possible, but at this time the physiological functions of calamus have not yet recovered, so it is not suitable to water too much. Just keep the soil moist and let the calamus gradually adapt.

3. Dry-yellow

Different from drought-yellow, dry-yellow is caused by air humidity being too low. This situation is prone to occur in midsummer or in indoor spaces with heating in the north. Because the air humidity is low and transpiration is strong, calamus very easily develops yellow leaves and scorched tips. For dry-yellow, first increase the amount of watering, then consider making a water tray or sand tray. Place a brick at the bottom of the water tray, do not let the water cover the brick, place the calamus pot on the brick, and artificially create a small environment to increase air humidity. The principle of the sand tray is similar. If it is summer, pay attention to shading, or place the calamus in a cool and ventilated place.

4. Scorch-yellow

Calamus is a shade-loving plant, and generally it is enough to place it in a place with scattered light. In winter and spring, it can be given some sunlight appropriately, but if it encounters strong direct sunlight, calamus will develop yellow leaves and scorched tips. At this time, pay attention to putting it back in a cool and ventilated place.

5. Alkali-yellow

Calamus likes a weakly acidic growing environment. If the water quality is on the alkaline side, or if it sits in a tray for a long time and salt and alkali accumulate in the potting soil, then the calamus leaves will naturally turn from green to yellow. Usually, try to use clean water and do not let it sit in a tray for a long time. If alkalinity is severe, you can neutralize it with ferrous sulfate solution, but considering the actual situation, I think it is easier to just change the soil and repot it.

6. Freeze-yellow

Calamus likes to grow in an environment of 15-25 degrees. Below 10 degrees, growth is relatively slow. Below 5 degrees, it should be brought back indoors or given extra cold protection. Some people say that calamus may not necessarily be harmed at zero degrees or even below zero, but why take that risk? For example, last winter, many people's calamus was damaged by freezing. When freeze-yellow occurs, the yellow leaves should be cut off as soon as possible and the plant placed in a warm environment, in the hope that the roots and leaves will regrow.

When calamus develops yellow leaves or even withering, we must first find out the cause. Once the cause is found, we should promptly treat the symptoms accordingly, hoping that the calamus leaves will turn from yellow to green as soon as possible. Moreover, the causes of yellow calamus leaves are not all the same, so we must treat them seriously and investigate carefully in order to perfectly solve this problem.

The above is a summary of some cultivation points for calamus, hoping it can help you.