Perennials are plants that live more than one year, usually at least three years. Many live much longer. Many will die to the ground in the winter, but will come back from their roots. Some are evergreen, which means that they do not lose their leaves in the winter. Many perennials spread and must be divided to encourage healthy growth. The blooming season is not usually as long as annuals, but perennials can be enjoyed for their foliage after they bloom.