First, the reason why beginning of spring cactus can be placed outdoors:
1. The suitable temperature for cactus growth is 20 ~ 30℃, with the highest temperature not exceeding 35℃ and the lowest temperature not lower than 5℃. The average temperature after beginning of spring is above 10 degrees.
2. Cactus needs sunlight for photosynthesis. After beginning of spring, it is sunny and suitable for cactus to grow outdoors.
3. Put an end to root rot caused by cactus staying indoors for a long time.
4. Cactus likes breathable and permeable soil, humidity and sunshine, and spring is just the right time.
2. Precautions for cactus placed outdoors:
1, when the rainy season begins in spring, pay attention to the humidity of tray planting, and don't soak the roots of cactus with water, which will lead to root rot.
2. beginning of spring should pay attention to the applicable ambient temperature of cactus at night.
3. Pay attention to the lighting and air purification of cactus.
Third, suggestions:
1. Put the cactus outdoors in the morning and bring it back indoors at night.
2. In the case of planting a large number of cactus, it is suggested to build a transparent tent to control the internal and external temperatures.
Fourth, the nursing methods of cactus
1. Selection of cactus cultivation soil
Soil is the place where plants grow, and most of the nutrients and water needed by plants are absorbed from the soil, so the soil has a direct relationship with the growth and development of plants. Potted cactus plants generally need calcareous sandy soil or sandy loam with good drainage and ventilation. Too fertile soil and soil with too much soluble salt are easy to cause root rot and injury.
The proportion of cultivated soil should be adjusted according to the species, plant size and climatic conditions of cactus plants in practical application. For example, seedlings need a lot of nitrogen fertilizer and water during the growth period, so the proportion of humus soil in the culture soil should be increased appropriately. In areas with heavy rainfall and high air humidity, the proportion of river and sand can be increased to maintain good ventilation and drainage of basin soil. Another example is the potted cactus placed on the outdoor balcony. The water in basin soil is easy to evaporate, so the proportion of garden soil and humus soil can be appropriately increased. Sometimes peat soil or charred rice husk can be used instead of humus soil, and the effect is also very good.
2. Fertilization method for cactus cultivation
Cactus plants need proper fertilization in the growing season, which is especially important for grafted varieties with well-developed seedlings and rootstocks. Topdressing can be liquid fertilizer such as fully decomposed bean cake water, fish intestine water and rotten egg water. And pay attention to the concentration. If it is light, the effect is not great, and if it is too thick, it is easy to burn the roots. The method of making liquid fertilizer by home cultivation is to put broken bean cakes, fish intestines and so on. Put it into a jar with a lid, add 2-4 times of water, and leave a third gap in the upper part of the jar for fermentation. After decomposition, add 10-20 times of water to the supernatant and smear it every 15 days.
For some terrestrial cacti that like calcareous soil, lime water can be applied 2 ~ 3 times during the growing period to prevent acidification of the basin soil. The method is to add 1 biological lime into 2kg of water, fully stir to dissolve the precipitate, and then irrigate it with the above clarified solution, and the water can be reused for many times.
3. Watering method for cactus cultivation
Although cactus plants are relatively drought-tolerant garden flowers, they should be watered and sprayed reasonably according to different varieties, seasons and plant sizes in cultivation management to avoid plant atrophy and premature aging caused by excessive water shortage.
The watering amount should be proportional to the temperature, and humidity management should be adopted during the growing season from May to 10. The temperature in midsummer is high and the evaporation is large, so it is necessary to water it every day, and it is advisable to water it in the morning and evening. In rainy season, the air humidity is high and the evaporation is small. It is necessary to keep the soil in the basin semi-humid to prevent the roots from rotting and the stems from rotting. When the temperature drops in late autumn, watering should be reduced accordingly.
Water should be strictly controlled in winter to keep the soil not too dry. The lower the temperature, the drier the soil should be. Generally, water it once every 1 ~ 2 weeks, and do it before noon on sunny days. Be careful not to let water touch the stem of cactus, otherwise it will easily cause stem rot. When the temperature rises in March and April, we should master the principle of watering between dry and wet, and water the cactus to achieve the requirements of releasing dormancy and restoring growth.
4. Temperature requirements for cactus cultivation.
The suitable temperature for cactus growth is 20 ~ 30℃, with the highest temperature not exceeding 35℃ and the lowest temperature not lower than 5℃. Keeping the temperature above 5℃ in winter can safely overwinter, and the drier the soil, the colder it will be. The temperature in winter should be relatively stable, and the temperature difference between day and night is too large, which is easy to cause freezing injury. It begins to grow when the temperature reaches 15℃ in spring, and begins to hibernate when the temperature reaches 35℃ in summer, and resumes to grow in autumn.
5. Lighting requirements for cactus cultivation.
Cactus is a kind of sunshine-loving plant, which is strongly positive, and its flowers can only be bright in strong sunlight. Therefore, adequate lighting should be given, especially in winter. Generally, tall, columnar and flat cacti are resistant to strong light and can be placed outdoors in summer without shade. However, the seedlings of smaller spherical species and common cactus should be semi-shaded in summer to avoid direct sunlight.
6. Transplanting and potted methods of cactus cultivation
From April to May in spring, when the temperature rises above 15 ~ 20℃, cactus plants begin to grow, which is the most suitable period for transplanting into pots. It can also be transplanted into pots in September ~ 10 autumn.
The flowerpot for potted plants is a well-ventilated plain-fired pottery pot. A few species with straight roots, fleshy roots or bulbous roots need deep flowerpots, while some cacti with underdeveloped roots can be planted in shallow flowerpots. Too large flowerpots will often cause the soil to be too wet, while too small flowerpots will limit the root development, which is not conducive to the growth and development of cactus plants.
Don't water potted cactus 2 ~ 3 days before transplanting, let the soil in the pot dry thoroughly, so as to buckle the soil out of the pot. After deduction, the old soil and dead roots in the lower part should be eradicated, and the long and curly roots should also be cut off. If rotten roots are found, all rotten parts should be removed until healthy roots are exposed. Large wounds can be coated with plant ash or sulfur powder, and then put into the basin after the wound is slightly dry.
Before serving dishes, both new and old pots should be cleaned and fully absorbed before use. The method of loading pots is to deal with broken pots, gravel, shells and so on. In the small holes at the bottom of the basin, the depth is one-fifth to one-sixth of the depth of the basin. Transplanted into a pot and placed in a cool place. At that time, water was not watered, only once a few days, and gradually moved to a sunny place. Half a month in spring is not suitable for fertilization, and fertilization can only be carried out in autumn until the following spring.
Five, cactus breeding matters needing attention
(1) Cactus seedlings should be changed once a year. Planting plants does not require changing pots every year. However, after a certain period of time, the nutrients in the basin tend to be exhausted, the roots are covered with the soil, or the soil becomes hard due to frequent watering, which is not conducive to drainage and ventilation and is easy to cause root rot. Therefore, the pot is usually changed once every 2 to 3 years. Fast-growing varieties can be larger than the original pots when changing pots, so it is more appropriate for the original pots to be nested in new pots. In the process of cultivation, the topsoil on the surface of the basin should be loosened frequently to make the soil well ventilated and the roots grow.
(2) In the cultivation management, plants that are often kept dry to a certain extent and have sufficient sunlight have light stems and slow growth, but their spines and thorns are developed, robust and beautiful. Plants often exposed to high temperature, high humidity and low light grow rapidly, with soft stems and bright colors, but the thorns and thorns are underdeveloped and the color characteristics are not obvious. For example, red thorns usually turn dark brown. So the amount of watering should be adjusted according to the purpose of cultivation.
(3) The water quality for watering and spraying should not contain too much sodium chloride and other salts. Generally, rainwater and well water can be used, but the water temperature should not be too low, and it is best to approach the temperature. Tap water should be put into the water tank 1-2 days before use. If you raise fish at home, it is more appropriate to water potted plants with fish tank water.