Annuals complete their life cycle in one year, they grow from a seed, flowers and set seed, after which they die. Chickweed and Sweet Peas are both examples. Also commonly known as annuals are Ephemerals – these can complete many life cycles in one year, such as the pernicious weed Bittercress. Many bedding plants are treated as annuals but in fact frost-tender perennials, such as petunias
Perennials live for more than two years and in most cases, many years. Trees, roses and shrubs fall under this category, these have a permanent structure, herbaceous perennials grow and bloom over the spring and summer and then die back every winter, their root-stock (or crowns) surviving below ground to re-shoot again in the spring. All perennials are either deciduous, dropping their leaves every Autumn, or evergreen, retaining their foliage all year.