Left unpruned, bay laurels can grow quite large, around 50 to 60 feet high, although on average they reach a mature height of 20 to 25 feet. Retaining the central leader will encourage height. However, this is a very malleable tree and can be kept much smaller, particularly if you want to use it as a border or screen in your garden. Container-bound bay laurels will typically reach a mature size of five to six feet. Bay laurels grow slowly, usually at a rate of a few inches per year.