Brentwood is a selected clone of the species C. cooperi. It is much faster in growth than other tree ferns and can grow to be 15 feet tall in 10 years along the lower California coast where you may see 30 foot specimen trees with fronds 6 to 8 feet long. Its roots form the trunk and it benefits from watering its trunk, as well as the soil. It may be used as an annual for special effect in the garden in cold winter areas, but leave them in their containers and bring them in before freezes occur. It is normally grown in 5 gallon, 15 gallon and larger containers for the landscape trade. It is safe to leave in landscaping where the winter temperatures do not fall below 26F.