Along the west coast of north america, from california to british columbia, english holly (ilex aquifolium), which is grown commercially, is quickly spreading into native forest habitat, where it … Discover how to grow holly plants with this complete guideâ€care tips, planting advice, and the best proven winners® holly varieties for year-round beauty. Voted the 2003 holly of the year by the holly society of america, the leaves have a distinctive tortoise shape and are typically 3” long and 2” wide.