Alchemy is consists of several parts:
Cultivation Resources' Creation
Every alchemist can create some resources like pills and medicines that assist in the cultivation. It is the prevalent part of alchemy, to the point that ordinary people consider it to be alchemy.
Plants Cultivation (养药种草) is an ability to cultivate medical plants (Spirit Medicines) to increase their potency and efficancy. Each plant is different and requires different fertilizers for its growth and the formulas for fertilizers vary from alchemist to alchemist.
Yuan Caihe, one of the Four Alchemy Prodigies of the Stone Medicine World in the current generation, is considered to be the best and most talented alchemist in Plants Cultivation. Her achievements and talent in this regard were praised even by Li Qiye, who compared her to Alchemy God.
Wood Mastery (御木) is a techinque that only Legendary Alchemists can use. It allows one to borrow the power of plants and stimulate their growth to incredible degree. It is different and more simple than the Plants Cultivation as it uses the plants as a weapon rather than a resource for futher refinement.
Insect Mastery (御虫) is a techinque to control poisonous creatures.
Insect Swarm Alchemy Emperor is best known for his abilities in this regard, and his lineage, the Insect Swarm Valley is world famous as the only lineage in the Stone Medicine World that possesses the manuals for this art.