There are many names that can be given to the Arbor Day saplings. The following are some of the more meaningful ones. I hope you will adopt them.
Xinxin tree: describes the vigorous growth of grass and trees; Rong: lush, from Tao Qian of Jin Dynasty's "Returning Letters": "The wood is happy to flourish, and the spring starts to flow."
Manman tree: describes long-lasting. As time goes by, it becomes more lush day by day. From Ban Gu's "Hanshu·Liyuezhi": "The vines are luxuriant, and the zhi becomes a spiritual flower."
Qianqian tree: The appearance of lush green vegetation. An energetic look. From "Liezi Li Ming" by Liezi during the Warring States Period: "What a beautiful country! It's lush and full of beauty."
I'll add a few more below.
Jiahe tree (a sapling that grows vigorously), cedar king (like snow and frost, it will not succumb despite the wind and frost), and cypress tree (hope to stand tall like a pine and cypress in the future).
Yongliang tree (forever bright, rooted in the earth), spring blossom (tree planting is the romance of spring), sanbishu (green towering tree).