A Subtle Art


Using small-flowered Clematis species, Japanese nurseryman Kazushige Ozawa created a group of quietly ravishing hybrids

THE LATE JAPANESE HYBRIDIZER KAZUSHIGE OZAWA’S work with clematis spanned almost four decades, during which time he produced a wide range of distinctive and beautiful hybrids. I knew his name because I grew his best-known hybrids, ‘Asao’ (1971) and ‘Kakio’ (‘Pink Champagne’; 1971). I was especially fond of ‘Asao’, which in mid-spring puts on a magnificent display of deep rose flowers, whose sensuous sepals display pale centers while retaining a richer color along their margins.

But I was not at all prepared for the phone call I received in the spring of 1992, which opened a door to the intriguing world of Japanese clematis. The caller was Mikiko Sugimoto, wife of Kozo Sugimoto, a clematis hybridizer whom I had met just a few months earlier. “Mr. Ozawa has had a dream,” she said. “He would like to visit the Harvey Clematis Collection in Hamilton, Ontario, and then go to Washington, D.C., to see John Wurdack. Could you arrange this and be his guide?” Although I did not at that time know of the Harvey Collection or John Wurdack, and I had not yet met Mr. Ozawa, I readily agreed, even though my Japanese was rusty.

During the course of our trip, Mr. Ozawa spoke openly about his newest plants. As he did so, the reason for our journey became clear: both Anne Harvey and John Wurdack had provided him with seeds of North American Clematis species, which had in turn become the parents of his new hybrids. Because of the success of these new crosses, Mr. Ozawa felt compelled to pay his respects to these two individuals.

Along the way, we discussed the role of flower shape in clematis crosses. I was concerned that most Americans were primarily interested in large-flowered hybrids and didn’t appreciate plants with bell-shaped flowers, although they were my favorites. When he left me, Mr. Ozawa gave me a rooted cutting of Clematis ‘Rooguchi’ (pronounced roe-GOO-chee), saying he hoped that it would bring needed revenue to my new and struggling nursery. His hopes turned out to be well founded, for, contrary to my expectations, ‘Rooguchi’ has proved to be a better seller than any of the large-flowered clematis we offer.


A year later, I was fortunate enough to visit the Ozawa nursery in Kawasaki, Japan, and was able to see the original plants that Mr. Ozawa had raised from the North American seed he had received. I also saw hundreds of his crosses.

I was surprised to discover that Mr. Ozawa’s nursery was devoted to cut-flower production. His customers were people who performed the Japanese tea ceremony, and greatly valued the understated beauty of a single cut flower placed in the tea room. Because of its role in enhancing the setting, the flower’s appearance was extremely important. Mr. Ozawa realized that flowers used for this purpose needed long stems, interesting shapes, and subdued but rich colors that appealed to Japanese tastes.

Thanks to the luster of their thick and waxy sepals and their distinctive bell-shaped flowers, the North American species that Mr.

Ozawa had assembled—which included Clematis addisonii, C. crispa, C. ochroleuca, C. reticulata, and C. viorna—were in most respects perfectly suited to his breeding goals. These species did present one problem, however: most of them have relatively small flowers.

Mr. Ozawa realized that the solution lay in crossing the small-flowered American species with the herbaceous C. integrifolia, which has relatively large, nodding, bell-shaped flowers, with spreading, often twisted sepals. The flower color usually ranges from pale lavender blue to deep blue. It is also very hardy and very amenable to cross-pollination by other species. Mr. Ozawa had used C. integrifolia in the past, and had even made several selections of it, including ‘Hanajima’ (1986), a dwarf pink form with twisted sepals, and ‘Yubune’ (1992), a taller form with larger pink flowers. He also made many blue-flowered selections, and his violet-blue form is now a standard in the Japanese nursery industry. It was, in fact, a cross between C. integrifolia and C. reticulata that produced ‘Rooguchi’ (1988), which bears one-and-a-half-inch, waxy purple nodding bells on fairly long stems.

Although ‘Rooguchi’ was raised for the cut-flower trade, it has proved to be an ideal border plant, reaching nine feet in height and blooming from June to August (sometimes September). The inclusion of C. integrifolia blood gives this plant both incredible hardiness and a tolerance of heat and humidity—it is as much at home in upstate Michigan and Wisconsin as in the torrid Gulf States.

During my visit to the nursery, Mr. Ozawa showed me a picture of ‘Odoriba’ (1990), another cross using a North American species, in this case, I suspect, C. crispa. ‘Odoriba’ has all the exuberance and brightness of youth. Its four perfectly symmetrical sepals forming outward-facing bells that are bright reddish pink with crisply outlined white interiors. The numerous flowers stretch out on long stems in so many directions it may be overwhelming to some gardeners. However, the blooms appear from midsummer until early autumn, and are so attractive that I am sure it is destined to become a classic in the garden as well as in the vase.


In 1994, I was surprised to get a second telephone call from Mrs. Sugimoto. “Mr. Ozawa has had another dream. He wants to go to Texas to see Clematis texensis in the wild. Can you arrange this?” Of course, I again said yes.

This journey brought me to a closer understanding of the importance of color in Mr. Ozawa’s work. The most common form of C. texensis has somewhat pudgy, tubular flowers, scarlet on the outside and cream colored in the interior. But there is also a form with long, narrow, tubular flowers that are scarlet both inside and out. This was the form Mr. Ozawa wanted for his cut-flower business and for use in hybridizing. Although he greatly admired the early C. texensis crosses such as ‘Gravetye Beauty’ and ‘Sir Trevor Lawrence’, he wanted to create a flower that had both the shape and subtle scarlet of the slenderer form of C. texensis, whose qualities he felt were a perfect fit for the tea ceremony.

Mr. Ozawa’s finds in the wilds of Texas became his treasures. His collection was given a place of honor in his garden, protected by netting and hand-fertilized so he could increase his stock. He called the seed strain that resulted ‘Aka’ (the Japanese word for red), and it became an important part of his cut-flower business. He also patented many unusual forms of this plant, but unfortunately they are difficult to propagate and so not yet ready for mass marketing.


Just before his death in December 2003, Mr. Ozawa distributed many thousands of seedlings among several Japanese nurserymen, so we will have to wait to see the further results of his C. texensis crosses. However, before his death, three new seedlings were released with his blessing. ‘Andante’ is an exceptional integrifolia type. Most pink integrifolias tend to be rose colored, but ‘Andante’ is a true cotton-candy pink, flowering freely from June to September if occasionally deadheaded. The sepals are nicely recurved, with a slight twist. At three feet in height, it is an excellent border plant. As an added bonus, it is lightly fragrant.

The two other seedlings come from Mr. Ozawa’s North American crosses. ‘Sophie Belle’ is unusual in that it forms a three-foot-tall herbaceous shrub with countless down-facing, rounded purple bells whose recurved sepal tips reveal a white interior. The foliage is mottled with dark purple. ‘Sophie Belle’ is not yet available for sale, but should be in the near future. ‘Little Belle’ is a cross using C. socialis. Somewhat stoloniferous in habit, it is best used in well-drained soil near the front of the border, where it can scramble about and where its tiny, narrow, powerfully fragrant tubes—deep violet within and pale lavender without—can be seen and sniffed.

I recall watching Mr. Ozawa staring silently at a new plant, his hands crossed behind his back, his head nodding slightly as if in conversation with himself. I asked him what he had noticed, and he told me he had just had an inspiration about a new cross he would like to try. I could see he was both dreaming and scheming. This combination of down-to-earth savvy and artistic sensitivity gave rise to the immense energy he invested in all of his projects. Thanks to his discipline and focus, Mr. Ozawa produced plants that succeeded brilliantly in achieving their original goal; serendipitously, these same plants came to have applications far beyond what he originally intended, and we are the richer for them.

Mr. Ozawa’s pioneering crosses using neglected North American species have resulted in some of our finest recent hybrids, and certainly heralded the growing international interest in smaller-flowered clematis. Although he may not have realized it, the dreamer was right on target. H

For sources of plants featured in this article, turn to page 67.

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