Broccoli is a fast-growing annual plant that grows 60–90 cm (24–35 inches) tall. Upright and branching with leathery leaves, broccoli bears dense green clusters of flower buds at the ends of the central axis and the branches. If left unharvested, those buds bear yellow flowers with four petals and produce silique fruits (a dry capsule). Broccoli thrives in moderate to cool climates and is propagated by seeds, either sown directly in the field or in plant beds to produce transplants. The heads, or florets, reach harvest in 60 to 150 days, depending upon the variety and the weather.