a biennial plant is a flowering plant that takes two years to complete its lifecycle. in the first year the plant grows leaves, stems, and roots (vegetative structures); then it enters a period of dormancy over the colder months. usually, the stem remains very short and the leaves are low to the ground, forming a rosette. many biennials require a cold treatment, before they will flower. the next spring/summer the stem of the biennial plant becomes much longer. the plant then flowers, produces fruits and seeds before it finally dies. there are far fewer biennials than either perennials or annuals.