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Journal American Rhododendron Society

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Dr. Glen Jamieson ars.editor@gmail.com


Volume 33, Number 3
Summer 1979

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The North Tisbury Azaleas
Polly Hill, Vineyard Haven, Mass

        It was my good fortune to spend the year 1929-30 in Japan. There I observed a charming plant used sparingly both in the Temple Gardens and the attractive Japanese Inn Gardens. It proved to be an evergreen azalea, a richer dark green, twiggier, and flatter to the ground than any azalea I had previously known. The flowers were brightly colored but not intrusive. As the Japanese placed it, the azalea was tucked in between the ground and a large ornamental rock to soften, but not obscure, the line of meeting. I can still see in my mind the serene gardens created with little more than a pine, a rock, and an azalea.
        Many years later, while they were still largely unknown in the United States, I was able to raise similar plants. They have come to be known as the North Tisbury azaleas. These azaleas include the dwarf hybrids derived from R. nakaharai, a Formosan evergreen azalea. They have been raised from seed at Barnard's Inn Farm on Martha's Vineyard Island. All are registered with the American Rhododendron Society. With a very few exceptions, the seeds for these plants came to me as gifts from Dr. Tsuneshige Rokujo of Tokyo, Japan. He used his large collection of both species and cultivars to make the crosses in his own garden. From seed he sent me until registration and distribution they have been my responsibility. At present there are 22 cultivars registered, so it seems an appropriate time to describe them in relation to each other and to their garden use. Gardeners will want to know about their culture, which ones bloom earliest or latest, and how they compare with each other in various ways.
        Martha's Vineyard is an island of 100 square miles, 7 miles off the south east coast of Massachusetts. All the plants are growing in well drained sandy soil, pH about 5.2, with pine needle mulch and a minimum of irrigation in summer. They are in partial shade under oaks pruned high, with a wind break of conifers to the north, and natural woodland to the west and south. Winter temperatures drop to a few degrees below zero F, (minus 20° C). In summer we seldom have temperatures over 90° F (33° C). Winds are strong and frequent; the air and water are pure. I shall attempt to tell about each cultivar, at least as I have come to know the plant in my garden.
        The species Rhododendron nakaharai is endemic to Taiwan. Early descriptions mention Mount Morrison on Taiwan as the native haunt of this beautiful and surprisingly cold tolerant azalea. (Please note the spelling of the last two syllables, "ha-rai". They should not be pronounced to rhyme with "marry". The last 2 syllables rhyme with "far cry", pronounced "hah-r-eye".) From Mount Morrison, Japanese botanists introduced the plant to Japan. My own clone of this species comes from the much smaller mountain near Taipei called Mount Seven Star, hence the name. The seeds for my introduction were collected at 800 M. on November 16, 1969, by Mr. C. S. Kuo of Tai Da University, and sent to me by a friend.
        R. 'Mount Seven Star' (carried under my number #69-074) is easy to recognize in my plantings at any time of year. The plant is very low, dense, and dark foliaged. The leaves are extremely red hairy, with broad triangular tips. In late June, 2" flowers are produced of pure cadmium red. The color is close to RHS color chart #40A. This is a deeper red than the other cultivars now available. Mount Seven Star will occasionally produce a twig that grows outside of the pillow outline of the plant and invite pruning and giving away. I have two other and different cultivars of R. nakaharai in my garden which keep a tight, smooth outline. They are also slower growing than Mount Seven Star. Some propagators have found Mount Seven Star tricky to make come into new growth after rooting. Fortunately, the hybrids are less particular in this respect. One conspicuous habit that the species nakaharai can give to its hybrids is the fasciation, or bundling, of the ends of the branchlets. The multiple twigs, arising from the end of a previously grown single twig, are neither distorted nor doubled together, but spray out in nearly equal, short, fan-like spokes from their point of origin. Each one displays its flowers facing upward, surrounded with a flat collar of leaves. The repetition of this type of branching and flattening of the foliage produces the smooth surfaces of the plants. The more fasciation, the smoother the surface becomes.
        The early blooming cultivars of the North Tisbury hybrids come into flower about June first. They are 'Wintergreen,' 'Joseph Hill,' 'Susannah Hill,' 'Hot Line' and 'Trill.'
        'Wintergreen' (#61-080-02) is a seedling from an envelope labeled "Nakaharai open pollinated". Two plants were registered from that seed packet, sent me in December, 1961, by Dr. Rokujo. The other is 'Marilee.' (Also, from that packet came one plant, typical of the species as it occurs in Japanese gardens, which I carry under #61-080-C. It is a small, light red flowered plant, similar to R. nakaharai 'Mariko,' slow growing, and a fine rock garden subject.) 'Wintergreen' keeps its foliage a conspicuously clear green all winter. Seventeen years old from seed, the original plant is now about 2 feet tall and over 5 feet wide, somewhat constricted in its location. The flowers are a medium red, twigs yellowish with red hairs. 'Wintergreen,' like the other hybrids, can take considerable sun, but welcomes wind protection and a well-drained soil, rich in humus.
        'Joseph Hill' (#61-079-04) is a controlled cross of R. nakaharai x 'W. Leith'. This is a first rate ornamental, with deep bright red flowers, cascading over a smooth pillow-shaped surface. The foliage is a rich green in summer and a smoky color in winter, glossy beneath the tiny hairs. The leaf tip is rounder than some, the twigs are reddish-brown. The whole plant is smoother than any other hybrid, spreading out and down. The original plant is 12-14 inches high and 5 feet wide in 17 years from seed. It set seed in 1978. 'Joseph Hill' is a very tightly twiggy plant which roots and layers easily.
        'Susannah Hill' (#61-084-01) is a cross of 'W. Leith', female parent, and R. nakaharai, male parent. The original plant and all its propagations seem to make exceptionally perfect circles in outline. The leaves are broader than most, and there is a reddish color at the tip end of the twig. The flowers are the darkest red of any. Often the stamens become petaloid, as the plant matures, giving a rosebud character to the flower. The flowers are a trifle smaller than its siblings, but very abundant. It is easily rooted. The original plant is 18 inches high and 4 feet in diameter. It is a strong grower whose branches grow out and down, creating a dome shape.
        'Hot Line' (#63-003-01) is one of the "Music Street Trio'. Its seed packet said, "From new forms of dwarf gumpos". In Japanese, gumpo is translated, "a group of phoenixes", a female symbol. In this context, gumpo is synonymous with Satsuki, the fifth month of the old Japanese calendar, June with us. I feel sure that 'Hot Line' carries no nakaharai genes. But a compact, dwarf, evergreen it is, with a particularly large, attractively ruffled flower. It is not a strident fuchsia, but just a wee bit hot purple red. It makes the other reds vibrate with it. The original plant is 18" tall by 4' wide in 16 years from seed. The branches grow out and up in a solid spread. It does not have the smooth surface of the nakaharai progeny, but is a densely branched plant. Once established, it can take a few degrees below zero F, but I suspect it is less hardy than some. It roots easily and I consider it the best of the 'Music Street Trio.'
        'Trill' (#63-003-03) is also an early one, from the same seed packet as 'Hot Line' and 'Andante'. Together they make up the 'Music Street Trio', named for a street in West Tisbury. They are about the first plants I named and registered: a pink, 'Andante', a red, 'Trill'; and the purely 'Hot Line'. 'Andante' I have lost, and doubt if it should have been named. 'Trill' has 2¾" ruffled, bright clear red, flowers, tumbling over the plant. 'Trill,' in my garden, is 18" tall by 3' wide, growing out and up, locally dense. It is not a smooth surfaced plant, but striking in flower and relatively hardy, once established. There is a translucence to the frilly petals I find most pleasing.
        The mid-season, mid-June, bloomers are; 'Louisa', 'Michael Hill', 'Pink Pancake', 'Jeff Hill', and 'Red Fountain'.
        'Louisa' (#61-076-05) is a cross of 'Chinyeyi' (a white flowered satsuki) and 'W. Leith' (a red flowered English azalea, listed by Hillyer). The flowers are a paler pink than any of the other hybrids, and also stay freshly in bloom for a longer period than any. They are smooth lobed, unruffled, and have a quiet distinction. The plant is round, 15" tall and 4' wide with a flat top. In November the reverse of some leaves is maroon with a prominent mid-vein. The older leaves are much larger than the new. New growth reaches out horizontally. Seed was set in 1978, the capsules and calyces are very hairy. Lacking nakaharai genes, I suspect it is not too hardy until established. It roots easily. 'Louisa' is a most agreeable pink, neither too bright nor too pale.
        'Michael Hill' (#61-077-01) is the favorite of many visitors. The cross is 'Chinyeyi' by R. nakaharai. 'Michael Hill' is a sibling of 'Pink Pancake' and 'Late Love'. The flowers of all three are a similar shrimp pink, about 2½" across with good substance. 'Michael Hill' is a vigorous spreading dwarf of excellent ground cover habit, striking in bloom. A young plant, given plenty of room, is 10" high and has reached out to 6 feet. This took 5 years from small rooted plants. It roots and layers in the mulch as it goes. The original plant is 24-30" tall and 5' wide in 17 years from seed, somewhat constricted by its location. 'Michael Hill' has a narrow leaf, a medium smooth surface to the plant with out and down branching which is densely twiggy. This plant seems extremely hardy, easy to root and easy to establish. It is hardy, once established, in zone 5, near Boston.
        'Pink Pancake' (#61-077-03) blooms a bit later than its sibling, 'Michael Hill', but does not flower as late in the season as its other sibling, 'Late Love'. This azalea is flatter than any other nakaharai except 'Mount Seven Star' itself. It was slower to catch hold than its siblings and remains lower, with shorter twig growth. It is now 15" tall and 4' wide in 1 7 years from seed. The surface is smooth, and it keeps a good green color well into winter. New growth is very short on top, and about 10" on the outer branches. The flower lasts well into July. Propagation is easy. One nurseryman prefers 'Pink Pancake' and 'Alexander' to any other North Tisbury azalea. He says they make up well in a container. Either one would be my candidate for a hanging basket or to hang down a wall, or even creep down a steep slope. Both have bright, attractive flowers, one pink, one red.
        'Jeff Hill' (#61-083-01) is the seedling of a Japanese plant called 'Maruba-osakazuki'. The tag showing the male parent was lost. It is quite different in appearance from the others, if one looks closely at details. The all over effect of the plant is stunning. The lightly ruffled flowers sparkle. They are light red with a purplish blotch, supported on fully 1 cm. long peduncles. This makes the flowers stand out from the handsome foliage, which is very like the foliage of a box bush. The leaves are a rich green and glossy, somewhat less flattened than the nakaharais. The plant measures 15" by 4' in 17 years from seed. Twigs are a greenish brown, and it can be propagated with ease. 'Jeff Hill' is possibly a trifle less hardy than the nakaharai hybrids, but only in its early years. It now flowers well after zero degrees F weather.
        'Red Fountain' (#61-084-02) was called to my attention when very young, by a nurseryman with a keen eye. The cross is 'W. Leith' x R. nakaharai. The leaf is large and rather round, similar to the leaf of 'Susannah Hill'. It is not surprising, as they are siblings of the same cross. The sturdy branches, a trifle coarser in texture, reach up at first, then arch down, in a conspicuous fountain-like curve. The original plant is 18" tall and 4' in diameter. The flowers are a strong red, similar to 'Joseph Hill' in color. The twig color is reddish.
        The late bloomers are 'Alexander', 'Marilee', 'Gabrielle Hill' and 'Late Love'. They flower in late June and well into July. And 'Late Love' lingers on into early August with a few welcome blossoms.
        'Alexander' (#63-001-01) is the only one registered from the cross of R. nakaharai and a strap-petaled azalea called 'Kin-no-sai'. Both parents are bright red, as is 'Alexander', no trace of purple present. The flower buds may be the hardiest of all the North Tisburys. 'Alexander', as well as 'Michael Hill', succeeds in zone 5 after it has achieved some size. With snow cover it should be worth trying further north. The original plant is about 15" high, and 6' wide in 16 years from seed. In form it is a billowing mound. A young propagation, well sited, is 5" high with a 4' spread. This is a fine ground creeping, prostrate plant. By cutting off a few wild shoots, one easily achieves a smooth surfaced, undulating mass. 'Alexander' is the most easily recognized of the North Tisbury hybrids. The flower buds, which are visible from September until June, are red, very narrow and pointed, and the leaf petioles surrounding the buds are the same rufus red. The narrow dark leaves are in maroon clusters in November. They have conspicuous reddish hairs, long and flat and reaching forward. 'Alexander', in a well mulched border, will send its creeping branches probing in among the bare stems of taller plants, such as Ghent azaleas, or upright Rhododendrons, or Camellias, rooting in the surface mulch, and effectively keep down weeds while making a handsome carpet cover to the ground. In time, the centers will mound up if not pruned back. A Japanese gardener prunes much more frequently and relentlessly than the average American. All my original registered plants have been allowed to grow unchecked for 2 reasons. I feel I should know what they grow into unaided, and I have little time for cosmetic care.
        'Marilee' (#61-080-01) also blooms in late June. 'Wintergreen' and 'Marilee' came from the same packet of seed, "R. nakaharai, open pollinated". One blooms early and the other late. 'Marilee' is the most vigorous in growth of all this group, making a large size sooner than any other North Tisbury Hybrid. The original plant is now 2' tall and 6' across, constricted in its present position. The leaves are large, oval and fairly uniform in size. The growth is outward, not completely smooth, but well filled and dense. At present the smoothest plants are 'Joseph Hill', 'Pink Pancake' and 'Late Love'. In 'Marilee', the twigs are robust and yellowish, with reddish hairs. The flowers are outstanding, over 2½" across, with a bud hardiness equal to 'Alexanders', or nearly so. 'Marilee', even as a young plant in bloom, received comments from garden visitors on the brilliance and showiness of the flowers. The red flowers have a purplish blotch, and in the sun, this makes an eye-catching spread of color. There is much to be said for a plant that is hardy, easy to propagate, grows fast, and has style and beauty.
        'Gabrielle Hill' (#61-076-01) is a sibling of 'Louisa'. The cross is 'Chinyeyi' x 'W. Leith'. It has a 2¼" ruffled flower, with a wavy edge. It is the same basic light pink as 'Louisa', but with an added rosy-crimson blotch. It is an airy, sprightly azalea rather dissimilar to the others. The habit is vigorous and irregular, not too dense, the growth reaching out, then up at the tips. Twigs are a light yellow-green. The plant has definite charm, impossible to eliminate in any evaluation. Now, it is 15" tall and 5' across in 17 years from seed.
        'Late Love' (#61-077-02) (syn. 'Summertime') is a cross of 'Chinyeyi' x R. nakaharai, like its siblings, 'Michael Hill' and 'Pink Pancake'. The flowering begins in July and continues into August. The twigs are yellowish. At the ends of twigs the leaves are short, clustering around next years' buds. Further up the twigs the leaves are longer. The flowers are shrimp pink, with wavy edges, and 2½" across. The whole plant is a solid mound of branches, flowing downward and outward from the top of the plant. The original plant is 3' high and 5' wide, constricted by its position. Younger plants are 6" high and 4' wide, well designed to make a thick ground cover. In November an occasional leaf is bright red, sparking interest in the dainty pattern of the foliage. It seems that 'Late Love', like most of the nakaharai hybrids will creep out over the ground to fill any given space, rooting and layering in the mulch as it grows. One or another of those hybrids is in bloom from early June into August. It is regrettable that they have 2 possible drawbacks. They are beloved by rabbits, and they are susceptible to petal blight.
        There are other registered azaleas, grown from seed at Barnard's Inn Farm, not resembling those described above. An early selection, named 'Ladylocks' (#64-005-01) is a seedling of R. macrosepalum from Japan. The sepals are a full inch long, narrow, hairy, and glandular (sticky), surrounding a 3" flower of pale purplish pink, with a lightly frilled edge, and a lovely fragrance. The shrub is upright, to 5' at present, and blooms in early May. One must watch for white fly. I particularly like the pastel lavender color which blends well with white Glenn Dales, Kurumes in pale pink, and other spring things.
        In 1965, Dr. Rokujo sent me a packet of seed of "R. kaempferi var. leucanthum". "Some pink may be expected", he added. About 30 of the resulting plants were finally moved from the nursery to various spots around the farm, or shared with others. They bloom in mid-May, along with the other Kaempferis. Oddly, none of them were white, and none were the bright orangey red or flame of Kaempferi. All were compact in habit, and each is a slightly different shade of pink. For the most part they are a lavender pink. My progeny varied all the way from a bright reddish lavender to the palest off-white, the color of some of the earliest spring flowering cherries. I have registered two, 'Libby' and 'Corinna Borden'. I would like to have an acre of 'Libbys' (#65-041-01). There is something very attractive about the pink color and habit of that plant. Unfortunately, it is not the easiest to root. And for a long time I had almost no propagating material as a mouse girdled the main stem, very nearly to extinction, when the plant was young. If you are looking for a pink that has sheen, like pearly reflections, that is neither peach nor lavender, but a suggestion of each, that does not intrude on the landscape nor disappear in it, but is lovely to live with, that is 'Libby'.
        An off-white, palest pink, cloud of flowers tumbles over the branches of 'Corinna Borden' (#65-041-02) and stops every visitor walking by the border where it grows. The delicate color attracts both men and women. Both of these Kaempferis are perfectly hardy with me and should survive further north. The human Corinna is only 2, so there are no distributions yet from her plant, but that will come in years ahead.
        Dr. Rokujo sent me a group of 5 small cuttings with a few roots on each in 1957. They were unnamed, but selected from a fine collection in a Tokyo garden. They prospered and were given names of 5 of my Japanese lady friends. If they have other Japanese names, I have no way of knowing. They are: 'Eiko San', 'Matsuyo', 'Yaye', 'Yuka', 'Midori' and R. indicum 'Eiko San'. They are typically Satsukis, rather low and compact, as the group goes.
        'Matsuyo' (#62-036) is the most dwarf, basically white, with flecks, streaks, wedges, and whole flowers of salmon red.
        'Yaye' (#61-041) is more spreading and open, with a definitely blue color to the green leaf. It has a large open flower, 3½ to 4" across, white, sometimes with a salmon pink border around the flower. Occasionally a wedge or the whole flower is colored. Park Seed Co. sells 'Yaye'. The foliage of their plant compares with mine, but the flowers their plant produced in my nursery have far less white than mine. It may have arisen from a colored spot.
        'Midori', I lost, but am getting back this summer. I remember a large, single, white, wavy blossom with a greenish eye, very lovely.
        'Yuka' (#64-046) is the hardiest, with a rich dark green leaf and mounding habit. Basically all white, it very rarely produces color in an occasional flower. The all over effect is striking, the purest clean white against a dark green. Flowers can spread to 4" and ruffle gracefully, all single.
        'Eiko San' is,., different in that the flower is very double, long lasting and a light salmon pink, extremely attractive. There are 7 layers of 5 lobed flowers superimposed, to make the rose-bud effect. After registering it, I saw pictures of the southern cultivar (not the Lee cultivar) of R. indicum 'Balsaminaeflorum'. I feared I had added a new name to an old plant. An S.O.S. to Dr. Rokujo produced 3 different double pink azaleas he sent me for comparison. At least one of them, he thought might help straighten me out. He was not familiar with our southern cultivar of R. indicum 'Balsaminaeflorum', but assured me there were a good many similar cultivars actually all different individuals. I can well believe this is so and that 'Eiko San' is one of them.
        That is the current status of my Asiatic azalea registrations. The only U.S. native that I have registered is 'Marydel'. It has recently been written up in this bulletin, so I will say no more. Only this query:
        Where are all the fine selections of our other Eastern natives? R. occidentale is being handsomely distributed and documented in the West. Of the dozen or so deciduous Eastern species only a handful of named clones are in the trade. Let us get busy and celebrate our rich native heritage by selection, registration, and distribution. There should be a superior R. prunifolium from Callaway Gardens after all these years of specializing, and how about one or two selections from the superb Henry Foundation collection? Even that would be only a beginning.


Volume 33, Number 3
Summer 1979

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