In many forms of Wicca, Witchcraft in Paganism herbs are used in many different ways. From incenses, to tonics, to teas and ointments and even in spell work. Herbs play a huge roll in a number of magickal workings. Even if you are just doing healing or making oils or incense, or bath washes, there will be some form of herbs involved.
Herbs that are used in Witchcraft and in Wiccan magick are not always going to be the same as the herbs that are used to do conjuring. When doing conjuring work you will tend to use the roots of the plants whereas for healing, sachets, etc. you will be more apt to use the leaves and flowers. This is why in Hoodoo plant lore and practice it is referred to as rootworking and Witchcraft plant lore and practice is called herb magick.