Transpiration is a method for plants to eliminate excess water.
Plants contain the fact that a lot of their tissues are made up of dead cells and that they can even lose some sections, like leaves, to help with other wastes. Vacuoles within cells are where a lot of plant waste is kept. Waste materials may even be kept in fallen leaves.
Other waste materials, particularly in ageing xylem, are stored as resins and gums. Additionally, plants release certain waste materials into the soil all around them.