Boston ivy is a deciduous vine, losing its leaves in autumn after a bright scarlet and purple leaf display. Small green-white flowers appear in summer, followed by blue-black berries. In addition to providing great cover for fences, Boston ivy grows well on trellises and arbors, and as a ground-cover that covers rock piles or controls erosion.
Boston ivy grows extremely quickly, often adding 10 feet to its height in a single year, so you can expect Boston ivy to reach the top of a fence in a year. Boston ivy continues to thicken as time passes. Over time Boston ivy can reach heights of 50 feet, and a single plant can spread 5 to 10 feet wide.
Boston ivy attaches itself to surfaces in one of two ways as it grows: it is both a twining vine, meaning it can use tendrils to wrap around structures, and an adhering vine, meaning it uses holdfasts or suckers with an adhesive substance to attach itself. Its tendrils mean you could grow it on a trellis or chain link fence, while its holdfasts make it suitable for growth on wooden fences or brick walls as well.
Because Boston ivy grows both quickly and densely, you should have a fully covered fence within a couple years, depending on the height of your fence and slight cultural variations. Once your fence is covered, you will need to prune it back aggressively. Be aware that once it attaches to a surface using its suckers, the surface retains moisture, making it vulnerable to disease and rot.