Elm refers to the root bark of elm. If the pedicel is not removed, it may affect the quality and efficacy of Ulmus pumila, because the efficacy of Ulmus pumila is mainly concentrated in the root bark.

This elm is 3-5 years old. Elms are usually sown by drilling and will be picked in April. At this time, the elm has turned yellow, which is very suitable for seeds. Sun-dried, then sown, put into a hole at a certain distance, cover with a centimeter-thick soil, and then grow into seedlings. After 3-5 years, it begins to blossom and bear fruit.