I'm not so sure about the muggle equivalent to Herbology being Biology. I feel like it would be more easily & appropriately related to something a bit more specifically plant based- Environmental Science or something similar
Buzzfeed: Sarah Han. 31 Gifts That Will Make Any Hufflepuff Love You Forever. Bleed black and yellow. Some of these are precious and I'm just going to leave this here for when I need a smile... or have money.
Hogwarts subjects | Potions: Potions is a core class and subject taught at Hogwarts School of Witchcraft and Wizardry. In this class students learn the correct way to brew potions. They follow specific recipes and using various magical ingredients to create the potions, starting with simple ones first and moving to more advanced ones as they progress in knowledge. A standard potions kit includes plant ingredients such as Belladonna and supplies such as glass phials and weighing scales.
Hogwarts subjects | Herbology: Herbology is the study of magical and mundane plants and fungi, making it the wizarding equivalent to botany. Herbology is a core class and subject taught at Hogwarts School of Witchcraft and Wizardry, in which students learn to care for and utilize plants, learn about their magical properties and what they are used for. Many plants provide ingredients for potions and medicine, while others have magical effects of their own right.