Reason: Mugwort represents Zhaobaifu. It is a kind of medicinal herb that can cure diseases. When inserted at the door, it can make the body healthy.

The legend that mugwort can ward off evil spirits has been circulated for a long time, mainly because of its medicinal functions. For example, Zong Mao’s "Jingchu Sui Sui Ji" records that "when the rooster does not crow, pick mugwort." If it looks like a human being, pick it up and use it for moxibustion. It is very effective. If you pick mugwort in the shape of a human being and hang it on the door, it can cure the poisonous gas."

Most people also plant mugwort in front and behind the house. The custom of seeking good luck. Taiwanese folk also post "noon couplets" on the Dragon Boat Festival, which have the same function as spiritual talismans. Some noon couplets have the following sentence: "Holding a moxa flag in hand to attract hundreds of blessings, hanging a pu sword on the door to kill thousands of evil spirits."

Extended information:

May is considered an evil month in popular belief, also known as the "Poison Moon". From a scientific point of view, it means that the temperature rises rapidly at this time. , the weather is hot, pathogenic microorganisms multiply in large numbers, poisonous miasma breeds, and people are easily sick. In order to cope with the evil month and spend the summer, people choose to eat some foods with higher nutritional value on the Dragon Boat Festival, and collect some herbs to hang, wear or take to prevent diseases.

Every household eats rice dumplings during the Dragon Boat Festival, and the most traditional one is red bean and glutinous rice rice dumplings. Red beans not only contain a variety of nutrients, but also have the effects of diuresis and dehumidification, blood and pus removal, swelling and detoxification, etc. They are a rare product for clearing away dampness and heat in summer.

In ancient times, on the Dragon Boat Festival, every household would hang mugwort and calamus collected from the fields on the door. Some used mugwort leaves, calamus, and garlic to boil water to bathe and spray the front and back of the house. Or use moxa leaves or calamus soaked in medicinal wine and drink it. People in some places also like to grind mugwort leaves and calamus into powder, wrap them in cloth, and make them into sachets (also known as sachets and sachets) for decoration, so as to avoid insect infestation with their aroma.

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People's Daily Online-Those things about the Dragon Boat Festival: What is the scientific basis for inserting mugwort leaves or calamus?