We first noticed this bittersweet growing in the birch grove about 5 years ago. It was not particularly fast-growing at the time, and it was confined to draping over one of the dead birches. A few years later, it had spread some more and at that time we noticed it was the Asian Bittersweet, the very invasive one that can grow and grow... and can interbreed with our native American Bittersweet. It was cut down and the following year either we didn't look for it or its growth was minimal. This summer I noticed it had draped itself over a number of nearby dead birches, and then recently, exploring further, saw how very extensive its growth is. The interior of the birch grove is almost covered with this vine. It is climbing way up into the dead trees, and beginning its ascent up the living ones too, as well as clambering across the ground and anything in its path. Like the Kudzu Vine! As with the native bittersweet, the stem of the vine grows thicker and heavier each year, but this one seems to grow at a greater rate of speed! It can reach about 60 feet in length and the stems can achieve a diameter of about 4 inches, which is substantial. It is a lovely, vigorous vine with the same pretty fruit as our native one, and it is easy to see why it is sold as a garden ornamental. But, it is very invasive...