Clematis hybrida ‘Rooguchi’

Opening up from black buds in May, the shiny, cobalt-blue flowers are extremely uniform, bell-shaped and about 2 inches long.


I recently did a ZOOM presentation on vines and covered well over 150 selections of woody, herbaceous and annual vines. I was very clear in mentioning that ‘Rooguchi’ clematis was my favorite by far. The value of vines in the landscape can’t be understated but so many become overly vigorous and unkempt in time. ‘Rooguchi’ has the benefit of being nicely constrained and offers flower power for almost five months. I first planted ‘Rooguchi’ over 20 years ago and oddly enough, it’s classified as a multi-stemmed, non-vining clematis that does need some minor support and guidance which is absolutely worth the effort.

First introduced in 1988 from the breeding work of the late Kazushige Ozawa of Japan, this plant continues to amaze all that grow it. There is a bit of debate regarding the parentage of this hybrid as it is thought to be a cross between C. integrifolia and C. x durandii although some authors indicate C. reticulata in lieu of C. x durandii. Mr. Ozawa, a well-known clematis breeder, wanted to develop a flower that would be perfect for a tea ceremony which calls for one lone blossom to be present in the room; hence the common name of solitary clematis. ‘Rooguchi’ continues to be popular in cut flower arrangements around the world.

Opening up from black buds in May, the shiny, cobalt-blue flowers are extremely uniform, bell-shaped and about 2 inches long. The flower detail also includes four recurving sepals with icy lavender margins. The solitary flowers, held on black stems, gently nod and hover above the foliage for maximum appeal. The bloom time is literally from spring until fall and this herbaceous plant will reach 8 feet tall and 3-4 inches wide in a single season. Fertile, well-drained soils are recommended and adequate moisture is advised to keep this plant happy. Tolerating rabbits, deer and walnut toxicity, this “scrambling” and “weaving” plant is a solid performer in full sun or part shade. This selection can tolerate high heat and won’t burn in full sun. The fuzzy, silvery seed heads (likely sterile) are also showy at the end of the season. ‘Rooguchi’ also has excellent resistance to clematis wilt although powdery mildew may be an issue at times or in areas of poor air circulation.

Mark Dwyer is currently the Garden Manager for the Edgerton (WI) Hospital Healing Garden after 21 years as Director of Horticulture at Rotary Botanical Gardens (Janesville, WI). He also operates Landscape Prescriptions by MD, a landscape design and consultation business.

Why grow Clematis hybrida ‘Rooguchi’?

  • Beautiful, deep blue, bell-shaped flowers
  • Extremely long bloom time
  • Wide hardiness range and adaptability
  • Excellent cut flower candidate
  • Attracts hummingbirds
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