Senescence constitutes a collective, progressive and deteriorative developmental process which ultimately leads to complete loss of organisation and function of plant or plant parts. Senescence involves a number of structural and physiological changes in the cells of senescing organ.
Cells undergo reduction of their structure. The membrane bound sub cellular inclusions are disrupted. It has been suggested that vacuole of cells act as lysosomes. It secretes certain hydrolytic enzymes which digest the cellular material. However, it has been observed that internal organization of chloroplast and mitochondria are reduced long before vacuole plays its role.
One of the quickest ways is to deadhead flowers. If flowers are allowed to go to seed, the plant ceases production of more flowers and becomes dormant, eventually dying. As long as there are no seeds being produced, the plant will continue to produce. This does not take into account such conditions as climate and hydration which will adversely effect the life of various species.