Jackmanii, a much used, standard ornamental vine, produces 7" flowers on the current season's wood.
It requires hard pruning ( 2' above the soil surface) every year in Early Spring; otherwise, flowers will be smaller than typical.
Note: An initial key to growing Clematis successfully appears to be keeping the plant's root system cool. The most vigorous vines seem to result from 3-4"of good mulch, plenty of moisture, and protection from the hot afternoon sun.
Photos courtesy of Toms Creek Nursery in Denton, NC & Riverbend Nursery in Riner, VA
Perennial Flowering Vine
6' - 10'
1' - 4'
Primary Foliage Color
Seasonal Foliage Color
Sheds Foliage in Autumn
Full Sun and Partial Shade
Average:Prepare planting area for adequate drainage. Poor drainage results in root rot.