Flowering clematis vines bear large, colorful flowers in shades of pink, red, purple and white. These vines grow very large, very quickly, although they are slow starters. The exact growth rate varies by type, but most grow quite fast.
Clematis has a fast annual growth rate. The exact rate of growth varies by type, but you can expect the vine to grow about 18 inches per year, on average.
Clematis vines can be slow to grow in their first year, because the plant is building its root system. Once the root system gets established, the growth rate picks up.
Some mature clematis vines, such as anemone clematis, can grow 20 to 30 feet tall. Other vines, which feature larger flowers, average 12 to 15 feet in height, and herbaceous clematis grows 2 to 5 feet tall.