A compact-growing flowering vine that matures up to 6 feet tall and no wider than 3 feet, the Asao clematis cultivar bears its blooms earlier than others, in late spring. The large, creamy pink flowers with a pale yellow center of stamens measure 4 to 5 inches in diameter. Petal edges blush a slightly dark shade of pink. Grow Asao clematis in a fertile, humus-rich soil that is moist but well-drained. According to the "A-Z Encyclopedia of Garden Plants," this variety grows best in partial sun to lightly shaded exposures. Mulch the soil to keep the roots cool and moist across the summers in U.S. Department of Agriculture hardiness zones 4 through 9.
Overall, Asao clematis doesn’t need much pruning. Don’t perform a harsh cut-back pruning after the summer solstice, as new growth must mature before the return of fall frosts later. Clematis vines produce flower buds from woody stems that grew and matured the previous summer, so don’t prune too much old growth away, even in spring, if you choose to prune then.