The process of aging affects most, if not all, living creatures, from single celled yeast to multi-cellular mammals and plants. The DNA end-replication problem along with the tissue-limited expression of telomerase led to the telomere hypothesis of aging, where limits on cellular proliferation are genetically encoded in the lengths of a cell's telomeres. Support for this hypothesis has been found in several organisms, from worms to mice to humans. While development, and therefore the process of aging, is quite different between plants and animals, telomere biology between these organisms is fundamentally the same. Do telomeres, then, also play the role of a molecular clock in plants? In this review, we explore the current knowledge of the relationship between telomeres and aging in plants in three specific cases: leaf senescence, aging of perennials and seed longevity.