Cactus Seed Sowing Temperature
An introduction to the knowledge of cacti, a type of succulent plant, and the sowing temperature of cacti. Let's take a look together.
Sowing cacti is a great fun, but some gardening enthusiasts may not know the sowing temperature for cacti. After reading this article on the sowing method of cacti from the 2014 edition, their doubts will be easily resolved!
I. Sowing Time
1. Sowing temperature: Night temperature should be above 18 degrees Celsius and day temperature should be above 28 degrees Celsius. As long as these conditions are met, cacti can be sown in any season.
2. Best sowing seasons: Late spring, early summer, and early autumn. During these seasons, the night temperature is between 20-25 degrees Celsius (most important), and the day temperature can reach 35-45 degrees Celsius under sunlight, with a temperature difference of more than 15 degrees, which is the season with the highest germination rate.
3. Summer: Although the day temperature can definitely meet the sowing requirements, the night temperature is above 25 degrees Celsius, and in some areas, it even hovers around 30 degrees. Sowing during this time will reduce the germination rate of the seeds, and it may not germinate at all. Moreover, if the temperature is too high during the day and the plastic film is not opened in time or there is not enough ventilation, it is easy for the seedlings to rot.
4. Winter: If you don't have suitable conditions and enough confidence, don't try to sow in reverse seasons, as it will waste time, energy, seeds, and severely affect your confidence in sowing.
II. Soil and Pots
1. Soil: Coarse sand, peat, coconut bran, vermiculite, coal ash, red jade soil, and wood ash. There are no strict requirements for the sowing soil. Just follow one principle: the cheaper, the better. You will deeply realize this when you do a large-scale sowing later. The above materials can be mixed and used, with no strict proportions, very casual, as long as they meet the three conditions of being breathable, water-permeable, and having a particle diameter of 1-3mm.
2. Pots: Black plastic pots. The depth of the pot should be 6-10cm. A pot that is too shallow is not conducive to the downward growth of the young roots. Plastic pots are better at retaining water, making it easier to estimate the weight of the pot and judge the moisture content of the soil. Black pots are good at absorbing more heat, shielding light from passing through the pot into the soil, and increasing the space for root growth.
III. Light
1. Avoid long rainy periods: As long as the "one" condition is met during the sowing period, sowing can be done at any time. The only thing to avoid is the long rainy season, such as the Meiyu season in the Jiangnan region, which lasts for 2-3 weeks with consecutive rain, high humidity, and temperatures around 30 degrees Celsius. At this time, the bacteria in the seedbed multiply uncontrolled, often leading to seed mildew and seedlings disappearing overnight.
2. Light: Seedlings require direct sunlight, but the light should not be too strong. Under full sunlight, 80% shading is needed. In a balcony at home, you can cover it with a shading net of 70-80%, or cover the seedbed with a layer of newspaper with countless 5mm holes. Moderate light can control the shape of the seedlings and ensure their health. Insufficient light will cause the seedlings to grow into green bean sprouts, which is not conducive to later growth, and they may die upon exposure to strong light.
3. Short rainy periods: There is no need to avoid consecutive 2-3 days of rain. The seeds can still germinate normally during short rainy periods.
IV. Sowing Steps
1. Fill the pot with soil: Fill the mixed soil into the pot until it is level with the pot opening, then tap the bottom of the pot a few times with your hand. The soil will naturally settle to 1cm below the pot opening, which is suitable for covering with plastic film and later watering and maintenance. There is no need to consider the "coarse particles at the bottom of the pot and fine particles on the surface" mentioned in the past.
2. Soak the pot: Place the pot in water to soak, with the water level at half the height of the pot. After half a minute, the soil is basically saturated with water, then remove the pot and set it aside for use. There is no need to disinfect the soil with potassium permanganate solution or microwave.
3. Sowing: a. After soaking the pot, you can sow immediately, spreading the seeds evenly on the surface of the soil. Gently sow the seeds using the thumb and index finger, and you can try the sensation on a piece of white paper first.
b. You can also do spot sowing, using a toothpick slightly moistened with water to pick up the seeds and gently place them on the seedbed.
c. It is best to use a separate pot for each variety. I sow 50-100 seeds in a 10x10cm square pot.
d. Do not cover the cactus seeds (including most succulent plant seeds) with soil after sowing, as they will basically not be able to break through if covered with soil.
e. There is no need to pre-soak the seeds, as it is too complicated and may not necessarily improve the germination rate. The method I introduce here is the simplest, and if you must soak the seeds, it is not opposed.
4. Insert a PVC label after sowing and write the name of the seed (including the Latin name), quantity, and time on the label with a pencil. The label is very important, and you will realize this when you collect more and more varieties.
5. Disinfection: After sowing, spray the surface soil and pot evenly with a solution of carbendazim (diluted according to the instructions). Disinfection is still necessary for beginners. In my greenhouse sowing process, due to the large amount of sowing, I simplify the steps and have omitted this disinfection step.
6. Cover with plastic film: After disinfection, cover with transparent plastic wrap or other transparent plastic film. This step is very important. Covering with plastic film can increase the humidity of the seedbed to over 95%, and the seedlings need to absorb enough water to break the shell and germinate.
7. Shading: Follow the standards in section "III.2, Light". If your sowing environment is exposed to sunlight for 1-2 hours in the morning and evening, there is no need for shading.
8. Germination time: Wait for the seeds to germinate after sowing, without opening the plastic film for ventilation. Since different varieties have different germination times, some may germinate in 2-3 days, while others may take 10-15 days.
I need to elaborate a bit here. The reproduction of plants is greatly affected by natural environmental changes. Therefore, to ensure the propagation of species, the germination time of seeds of many varieties is not unified. Some seeds may germinate the following year, which is especially evident in seeds collected in summer and autumn. Seeds sown in autumn have a low germination rate, but it is surprising to find that seeds from the previous year are germinating in the spring. So don't give up on seeds that don't germinate after sowing.
V. Maintenance after Germination
1. The seedlings should be immediately placed in a ventilated environment for maintenance three days after germination. There is no need to keep them covered after this. The primary consideration after the seeds have germinated is to ensure the healthy growth of the seedlings. The earliest germinated seedlings are the strongest and must not be allowed to die. Later, more seeds will continue to germinate. Maintenance in a ventilated environment can inhibit bacterial reproduction and prevent phenomena such as rotting seedlings.
2. Light: From June to September, the sunlight is strong. Under full sunlight, the seedlings need 60-70% shading. After October, they can be maintained under full sunlight. Emphasize that sufficient light is beneficial for the healthy growth of seedlings. Don't worry about the seedlings turning brown. After germination, the seedlings will rapidly expand within half a month and then stop growing. Later, sufficient light is needed to promote root growth. Remember, the quality of the plant depends on whether the roots are strong. Especially for cacti and fish, the first half-year after germination is mainly the root growth period. After half a year (in winter and spring), you can see the ball-shaped bodies rapidly expanding, far surpassing the seedlings of those who insist on keeping them covered.
3. Watering: Keep the soil slightly moist within one month after germination. The seedlings are not afraid of water, and the seeds that have not germinated will continue to do so, while the seeds that have germinated will take root in the soil. After one month, alternate between dry and wet. When the surface soil dries, water after 1-2 days. The method can be soaking the pot or direct watering. Choose a sunny morning to water, and it's best for the moisture on the seedlings to evaporate within 2-3 hours. Watering in the evening will not evaporate in time and can easily cause the seedlings to have difficulty breathing and be infected with bacteria.
4. Fertilization: Fertilization is not very important during the seedling stage. Liquid fertilizer can be applied with watering. Seedling growth mainly requires nitrogen fertilizer, once or twice a year. I don't fertilize the seedlings and only apply some base fertilizer in the pot when they are transplanted to a larger pot.
5. Winter management: In winter, you can move the seedling pot indoors for maintenance. If conditions permit, you can build a warm greenhouse indoors or make a small warm box, cover it with plastic film to keep warm, and open it for ventilation for a while in the morning and evening. The seedlings can continue to be watered in winter. Since the water evaporates slowly in the greenhouse, the amount of watering should be controlled, and water should be added only when the soil is completely dry.
6. Transplanting: When the seedlings are crowded or the plants have grown to 1-2cm, they can be transplanted. Remove the seedlings, pull off some fine roots with your hand, and place them in a well-ventilated and shaded area to dry the roots for 3-5 days before potting them again. The purpose of drying the roots is to prevent wound infection.
The above is the complete content on the sowing temperature of cacti. Have the green plant enthusiasts understood it?