Blue Hollies are justly named because their dark green foliage has a blue overcast. The bark on juvenile twigs is purplish and in order to produce fruit, this female cultivar must be planted with its male counterpart. The growth habit for 'Blue Girl' is hardy, and it can reach a height of about 15 feet, with an annual growth rate of 12 to 18 inches. In the northern states, caution should be given to where in the landscape this tree is planted, in order to avoid the occurrence of burn in the cold winter months. Zone 5