Kelp needs sunlight in order to grow. It also needs a hard surface to grow on. The holdfast is a part that attaches the kelp to the ocean floor. The blade is the leaflike part that takes in sunlight to make food. The stipe is the part that connects the holdfast to the blade.
Giant kelp is one of the world's fastest growing plants.
It can grow as much as 300 feet in a single year. When the tops reach the surface, they keep on growing to form a floating mat. The kelp forest provides shelter and protection for many animals. Like a forest on land, a kelp forest is full of life.