How to Grow Calendula: Detailed Guide to Planting Methods and Care Tips

The flower stems of calendula grow straight upward, and the golden flower color looks especially like a lantern. The flowering period is also very long, making it very suitable as an ornamental flower. So how do you grow calendula?

1. Seed propagation

1. Sowing: Autumn sowing is often carried out after mid-to-late September: Disinfect the substrate. To disinfect the substrate used for sowing, the best method is to put it in a pot and heat it until hot; any pests and diseases will be killed by the heat.

2. Germination promotion: Soak the seeds in warm water (at a temperature similar to face-washing water) for 3 to 10 hours, until the seeds absorb water and swell. For very common seeds that germinate easily, this step can be skipped.

3. Sowing: For tiny seeds that are difficult to pick up with your hands or other tools, you can moisten one end of a toothpick with water and stick the seeds one by one onto the surface of the substrate, then cover them with 1 cm of substrate. After that, place the sowing pot into water, with the water depth at 1/2 to 2/3 of the pot's height, and let the water slowly soak upward (this method is called the “pot soaking method”).

4. Management: After autumn sowing, when a cold wave and low temperatures occur, you can wrap the flower pot with plastic film to help keep it warm and moist; after the seedlings emerge, uncover the film promptly, and let the seedlings receive sunlight before 9:30 every morning or after 3:30 in the afternoon, otherwise the seedlings will grow very weak; after most of the seeds have sprouted, proper thinning is needed: pull out the diseased and unhealthy seedlings so that the remaining seedlings have a certain amount of space between each other; when most of the seedlings have grown 3 or more leaves, they can be transplanted into pots.

2. Cutting propagation

1. Cutting substrate: This refers to nutrient soil, river sand, peat soil and other materials used for cuttings. For home cuttings, it is difficult to obtain an ideal cutting substrate due to limited conditions. It is recommended to use the already prepared and sterilized cutting substrate provided by this site; medium-coarse river sand can also be used, but it should be rinsed several times with clean water before use. Do not use sea sand or river sand from saline-alkali areas; they are not suitable for the growth of flowers and plants.

2. Selection of cutting branches: The branches used for cuttings are called cuttings. Usually, in combination with pinching work, the thick, pest-free and disease-free top shoots that are pinched off are used as cuttings, and the top shoots are used directly for cuttings.

3. Temperature: The optimal temperature for rooting of cuttings is 18°C to 25°C. Below 18°C, rooting of cuttings is difficult and slow; above 25°C, the cut ends of the cuttings are susceptible to infection by pathogens and rot, and the higher the temperature, the greater the proportion of rot. When low temperatures occur after cutting, the main measure for keeping warm is to wrap the flower pot or container used for cuttings with film; when the temperature is too high after cutting, the main cooling measure is to shade the cuttings, blocking 50 to 80% of sunlight. At the same time, spray the cuttings 3 to 5 times a day. On sunny days with higher temperatures, spray more often; on cloudy and rainy days with lower temperatures and higher humidity, spray less often or not at all.

4. Humidity: After cutting, the relative humidity of the air must be maintained at 75 to 85%. Humidity can be increased by spraying the cuttings 1 to 3 times a day. On sunny days, the higher the temperature, the more frequent the spraying; on cloudy and rainy days, the lower the temperature, the less frequent the spraying or no spraying. However, excessive spraying makes the cuttings susceptible to infection by pathogens and rot, because many kinds of pathogens exist in water.

5. Light: Cutting propagation cannot do without sunlight, but the stronger the light, the higher the temperature inside the cuttings, the more vigorous the transpiration of the cuttings, and the more water they consume, which is not conducive to the survival of the cuttings. Therefore, after cutting, 50 to 80% of sunlight must be blocked. After the root system grows, gradually remove the shade net: on sunny days, remove the shade net at 4:00 every afternoon, and cover it again before 9:00 the next morning.

Growing calendula is relatively simple, and its conditions for growth and propagation are not harsh, making it very suitable for the general public to grow.