Irish Moss is a small perennial seaweed that grows best in water that is between the low tide mark and 30 feet of depth. The plants thrive in water ranging between 5 and 15 degrees Celsius. The life cycle of the plant begins in a seed form. These seeds are shed by the plant annually. The plant attaches to the ocean’s rocky bottom in a way that resembles being glued to the rocks. The small plant reaches maturity in three to five years, at which time the many branches that cover its top may range in colour from a light yellowish green to an almost purple colour.

Mature plants can reach heights up to seven inches and have the unique ability of growing from the bottom. Unlike plants that grow on land, Irish Moss must grow from the bottom due to the harsh environment in which it lives. Many times throughout its lifespan a storm will whip the water up around it and in turn break the top of the plant off. Growing from the bottom allows the plant to continue developing even after the top has been broken off.