Perennial Flowers lasts three years or more. This means the plant will die back to the ground in the winter, and come up again the following year on the same rootstock. This will only happen if the plant is winter-hardy in the growing zone it’s planted in (more on this below). The root systems are what survive through the winter, because the plants put energy into making the roots stronger than annual root systems. These plants last at least 3 life-cycles, versus annuals which just last 1 cycle. Some perennials can be grown as annuals and some can actually be evergreen in some warmer growing zones.