The germination of a plant is growth from a seed. Some plant varieties are not made from seed and require propagation from a cutting or graft to grow. Plants are broken down in the gardening world according to their life cycles. Knowing the life cycle of a plant helps a gardener to plant the garden accordingly.
Flowering plants grow from a seed. Seeds work as the egg of a plant, containing an embryo. The seed has a protective coat over it that prevents damage. According to the Offwell Woodland and Wildlife Trust, the temperature, light and moisture level must be right for a seed to germinate.
As the water penetrates the seed, the embryo sprouts from the seed coating. The root, or radicle, bursts from the seed coat and grows downward into the soil. Shortly after the shoot, or plumule, emerges from the seed, growing upwards towards the light. The leaves begin to show up. At full size they become true leaves. This is the point where the plant is transplanted. The plant begins to make its own food as opposed to surviving off the reserves in the seed.
Annual plants are those plants that complete their entire life cycle in a single year. The seed grows into a mature plant. At some point during the year, the annual plant will flower and release new seed to propagate into new plants. Once the annual plant flowers and produces seeds, it dies.
Perennial plants are those plants that survive for two years while completing the life cycle. During the first year, says Oregon State University, the plant produces the vegetative structure and leaves, and begins creating its own food stores. Some biennials begin producing seed in the first year, while others wait until the second. Once the biennial produces its seed, it will die.
Perennial plants live for 2 years or more to complete their life cycle. Perennials are further split into two more categories; herbaceous and woody perennials. Herbaceous perennials have soft stems that die back and return to the ground each year. New stems are produced from the crown the following spring. Woody perennials keep their stems throughout the winter, since the wood stems can resist cold weather.