What type of plants require a cold winter to complete their life cycle?

Biennial plants are specifically adapted to their life cycle, which includes two years for completion. In the first year, biennials typically germinate, grow leaves, and establish a root system, but they do not flower or set seeds. Instead, they require a period of cold, winter conditions to induce the flowering phase in the second year. This cold requirement is crucial for triggering the necessary physiological changes that lead to flowering and seed production.

Summer annual plants, on the other hand, complete their life cycle within a single growing season, thriving in warm weather and typically dying off when temperatures drop. Perennial plants can live for several years and do not rely on cold winters to complete their life cycle, as they usually flower and set seeds multiple times over their lifespan. Lastly, winter annual plants germinate in the fall, require a winter chill, and typically flower and set seeds in early spring, which differs from the two-year cycle of biennial plants.