Why can the famine ginseng fruit trees only give the essence of the sun and the moon once?

Ginseng fruit trees have no function of sealing sun essence. Ginseng fruit trees can only absorb the essence of the sun and cannot be sealed and preserved. The clue to the hidden treasure bought in the fortune teller may lead to a dead tree root. The roots of fallen dead trees are nourished by the nectar in the jade bottle in the well and the essence of the sun and the moon (purple gourd attracts dwarfs and Polaris alone). After careful care (watering dialogue), it will grow into a towering fruit tree.