Why did Tomb-Sweeping Day stick willow branches at home?

The legend about Tomb-Sweeping Day planting willow branches at home;

Legend 1: The custom of planting trees by inserting willows in Tomb-Sweeping Day is said to commemorate Shennong who invented various agricultural production tools and tasted all kinds of herbs.

Legend 2: When Jin Wengong and his ministers went hiking to worship Jietui, they found that the old willow trees that had been burned in those years had actually come back from the dead. Jin Wengong now named the old willow "Qingming Willow", and broke off a few branches on the spot and put them on his head as a souvenir. His ministers followed suit and became accustomed to each other. Tomb-Sweeping Day's willow crossing has become a symbol to commemorate meson push.

Legend 3: It is said that willow branches can ward off evil spirits, so inserting willow and wearing willow is not only a fashionable decoration, but also a prayer to ward off evil spirits. It may also be related to the custom of using willow branches to beg for new fire in the past cold food festival.