Bay trees will not withstand freezing cold weather. You will need to take the tree in for winter. It should be kept in a very bright location with plenty of light. It is also very common to overwater these trees in the winter because growth will slow. Be careful not to do so. It is also important to gradually acclimate the tree in the spring when you return it to an outdoor location. Make sure the outdoor spot has plenty of sun and use a water soluble fertilizer to promote growth. Do not expect it to grow quickly. Even in the best conditions these trees are slow growing.