The seeds that Zheng Qing was looking for from Zhang Ji Xin weren't ordinary plant seeds.
Indeed, Professor Li Qihuang of the Magic Potion class highly encouraged young wizards to try planting some herbs with less stringent growing conditions in their free time. However, this most certainly did not include Zheng Qing- heaven knows, if it were not for the few elves he kept occasionally watering his dormitory daisies, he would not even be able to keep a potted plant alive, let alone grow herbs.
What Zheng Qing requested from the Elder Zhang Da were the seeds of Speaker Flowers and the Shadow Preserving Herb.
