A sequence of a plant's life cycle traces its existence from its beginning through maturity and death. There is no one sequence that describes the life cycle of all plants; sequences differ according to whether the plant is an annual, a biennial or a perennial. The life cycles of perennial plants vary according to whether a plant is herbaceous, plants that have soft stems and die back, or if it is woody, a classification that includes numerous species of trees.
All plants go through a life cycle that begins with the sprouting of seeds Seeds come in many forms, according to the species of plant. The process by which seeds grow into new plants is called germination. All seeds have specific requirements to germinate; these requirements include the ratio of daylight to darkness, amount of moisture, abrasion of the seed cover, and even fire, and digestive enzymes obtained from animals.
In classic plant reproduction represented by flowering plants, the male part of the plant, called the stamen, produces pollen that fertilizes the pistil, or female, part of the plant, which is usually located at the base of a flower. This coming together produces the seed that grows into a new plant.
New plants do not always begin their life cycle from seeds. Some plants get their start through what is called asexual, or vegetative, reproduction. Tulips grow from bulbs. Strawberry plants grow aboveground runners called stolons, from which new strawberry plants grow. Many grasses reproduce through underground runners called rhizomes, from which new grass stems grow. The potato plant reproduces through underground tubers. Roses grow suckers from underground roots. In adventitious vegetative reproduction, new plants spring from leaves, stems or surface roots. The redwood tree grows adventitious stems from the lower part of its trunk.
Annual Life Cycle
Annuals start from seed, grow to maturity, bloom, produce seeds and die in one year. A summer annual completes its life cycle during the spring and summer. A winter annual complete its life cycle in the fall and winter. Such flowers as larkspur and foxglove are annuals
Biennial Life Cycle
A biennial needs all or part of two years to go through its life cycle. It produces leaves and bulbs or tubers the first year. After being dormant during the winter, it produces seeds, flowers and grows fruit during the second year. Carrots and beets are biennials.
When a biennial is subjected to an unexpected cold spell early in its first season or is subjected to drought, it might "bolt," or pass rapidly through two growing seasons in one year.
Perennial Life Cycles
Herbaceous perennials have soft stems. They usually die back to the ground during the winter and begin growing again in the spring. Dahlias and alfalfa are examples of herbaceous perennials.
Slow-growing trees and shrubs are woody perennials. Their woody stems can withstand winter cold. Apple, cherry and other fruit trees may require years before they produce seeds to grow new trees. Many slow-growing woody perennials reproduce through suckers and adventitious growth. Woody perennials can live for decades or even centuries.