Calendula (C.officinalis nana) has been a star in naturopathy such as Ayuveda, for it can be applied to our body externally or eaten. It is said to be useful for preventing muscle spasm, anti-inflammatory, benefit wound healing and scar formation, and menstrual pain relief.
The seeds of this annual herbaceous emerge at 20℃, and the best growing temperature is 15℃, which makes it one of the perfect flower species to be grown in Hong Kong's Autumn and Winter. Calendula usually emerges within 7 to 14 days, but these seeds emerged 3 days after DOS (date of sow)! As it reaches the 7th day, they are growig into healthy seedlings.
Calendula - Clear Orange one week after date of sow
Calendula Seed Sowing
Calendula seeds are crescent-shaped, approximately at the size of 1cm. In Hong Kong, they can be sowed after Autumn Equinox.
Place 2 to 3 seeds into 6~7.5cm pots (like these plastic pots), cover soil of approximately 1cm depth. Choose soil that is rich in nutrients and well-drained. Calendula prefers slightly alkaline soil. Some people mix akadama and peat moss, some use vermiculite to cover, but we simply used our potting mix to cultivate seedlings. You can also increase the ratio of perlite for better drainage.
The crescent-shaped seeds of calendula
Seedling Care and Transplanting
When seed emerged, move your tray or pots of seedlings to a place with bright sunlight and ventilation. Lack of sunlight may lead to leggy growth.
When 2 to 3 sets of true leaf appear, consider thinning. When 4-6 sets of true leaf appear and roots are formed to pot bound, it is the time to transplant.
After the seedlings are transplanted, you may consider adding fertilizer every week, but over fertilization will cause spindly growth and unhealthy plant too. If you are using our organic fertilizer, you may wish to add more than half a teaspoon every week. Remember calendula enjoys slightly alkaline soil, so you may want to add hydrated lime to balance soil pH.
Move seedlings to spots filled with sunlight and good ventilation
Flowering and Harvest
Calendula - Clear Orange can be grown part-shade, but best under full sun. Good ventilation is crucial. Flowering occurs 10 weeks after date of sow, and will delay 1 to 2 weeks if your pot is under 15cm.
If you want to ensure biggest medicinal benefits of calendula, it is best to harvest them in the morning after dew has dried, and when the flowers are not fully bloomed. Calendula leaves offers medicinal benefits just like their flowers, but you may wish to snip flowers only for full season harvest. Pick calendula early and frequently for more flowers, while also avoid emergence of seeds to prolong harvest.
Dried your calendula harvest, then you can create calendula oil, all kinds of beauty products like salve, or simply drink them as floral remedy.