JARS v44n3 - The Seidel Rhododendrons - Origins and Types

The Seidel Rhododendrons - Origins and Types
Erhard Moser
East Berlin, East Germany

Translated by David W. Goheen
Camas, Washington

The family Seidel, by the creation of newer "sorts and types" of rhododendrons from early in the nineteenth century until about 1930, became as famous in Germany as the Waterers in England for breeding new hybrid rhododendron creations. Theirs was pioneering work, especially for the production of winter-hardy hybrids that are suitable for the colder or continentally influenced districts of middle, eastern and northern Europe. Many of their hybrids are still considered standards for these regions.

It was, however, a surprise to me to find several Seidel hybrids listed even in nursery catalogs from the USA. Certainly, here in my area, several are grown that are to be recommended for winter-cold regions and are completely worthy of cultivation. Thus, it should be interesting for my rhododendron friends, members of the American Rhododendron Society, to learn something of the origins and breeding history of the Seidel hybrids.

The family Seidel is an old gardening family in Dresden, Germany. The family descended from Johann Heinrich Seidel (1744-1815), who after his formal schooling, educated himself at the then, very famous Kew Garden in London and the Garden of Plants in Paris. He also was kept busy in the garden of Prince William V of Orange.

In 1771, Johann Seidel returned to his home city and several years later was appointed to the Court Garden. He created, in his active years, a considerable plant collection. Thereby, the Prince of Saxony's ducal garden became very well known and was comparable with similar botanical collections in Europe. An inventory register for the year 1806 mentions 4,300 species and varieties of plants. In the register were many new and unusual plants, including seven rhododendron species. In 1807, he had already sold Rhododendron ponticum , which he, himself, had raised. The well-known German poet, Goethe, stayed with him many times and became stimulated, through his visits, to compose the "Metamorphosis of Plants."

In the year 1813, his sons, Jacob Friedrich Seidel (1789-1860) and Traugott Jacob Seidel (1775-1858), established the later world-famous horticultural concern "The Brothers Traugott, Jacob Seidel" in Dresden. They cultivated chiefly Azalea Indica [Belgian Indian or Indian Hybrid azaleas], "Hortensien" (named plants of uncertain origin), palms, rhododendrons and camellias.

Following the path of his father, Jacob Friedrich Seidel studied at the Garden of Plants in Paris from 1810 until 1812. In the latter year, he was impressed into the army of Napoleon in order to take part in the war against Russia. In his luggage, he took with him one of the first camellia species introduced into Paris. He deserted from the army on the way to the fighting and made his way back to Dresden. He then built up, especially, camellia culture and thereby became known as "Camellia Seidel." He laid the foundation stones for the Dresden peat-bed plant collection. After 1822, he began employing R. arboreum for rhododendron breeding in order to obtain red hybrids.

His brother, Traugott Jacob Seidel, later retired from the business operation and presided over the Botanic Garden in Dresden. Along with the botanist, G. Heynold, in 1843, he wrote the first book on rhododendrons. It contained a systematic description of the known, at that time, rhododendrons and azaleas as well as references to their garden culture. Also included were other ericaceous plants such as rhodora, rodothamnus, kalmia, leiophyllum and ledum.

In 1860, the son of Jacob Friedrich Seidel, Traugott Jacob Herman Seidel (1833-1896), took over the horticultural operation. At first there were the preliminary learning and travelling years that led him to John Standish at Bagshot in England and to France. In these places, there were already rhododendron hybrids in cultivation that he wished to acclimatize in Germany. Hitherto, in Germany, rhododendrons were sold chiefly as budded plants in pots and were wintered over in houses. After 1877, Traugott Jacob Herman Seidel began to breed winter-hardy rhododendrons for cultivation outdoors. To accomplish this, he acquired a pine wood near Dresden in order to test his crosses in the winter. As crossing parents, he employed R. campanulatum , R. caucasicum , R. maximum , and R. ponticum .

At this time the business specialized in azaleas, rhododendrons and camellias. Four hundred kinds of azaleas, eleven hundred kinds of camellias and a great number of rhododendron species and hybrids were cultivated in the Dresden garden. They displayed their plants at the great international exhibitions and sent their own plants to the World's Fair in Chicago in 1893.

The catalog of the family Seidel was quite extensive as the rhododendron offering list shows. However, it nearly completely lacked several breeding traits. In 1860, the hybrid, 'Jacob Friedrich Seidel', came out. This was an outstanding entry at an exhibition in Berlin and was followed by constant introductions of new Seidel hybrids. Unfortunately, most of these are known only by name. Only a few from that time period are in cultivation today, for example, 'Gerstäcker', a white hybrid introduced in 1880. However, another hybrid from that time is still often grown in the USA; it is 'Helene Schiffner', bred by Seidel in 1890. It is the only German hybrid that is distinguished with an F.C.C. (1893). In Germany, because of its lack of winter-hardiness, it is not often offered in nursery lists.

In 1891, Traugott Jacob Herman Seidel, turned over the concern to his two sons, T.J. Rudolf Seidel (1858-1918) and T.J. Heinrich Seidel (1864-1934). In the year 1897, a property with clear, light pinewoods in Grüngräbchen, about 40 km. north of Dresden, was acquired. The land was slightly peaty with a high ground water table. The winter climate was colder and rawer than that of Dresden.

It is now almost a "one hundred year epoch" since the Seidel brothers took over the land in Grüngräbchen. It has become a significant rhododendron breeding area. The Seidels' breeding aims were to produce winter-hardy rhododendrons with clear and stable flower colors, large closed blooming standards, bud set on young plants, a long and late blooming time, good and the darkest possible green foliage and compact stature. In order to produce red hybrids, they utilized the descendants of R. catawbiense crossed with R. arboreum . Also combinations of R. catawbiense with R. caucasicum and later R. smirnowii and R. japonicum var. japonicum ( R. metternichii ) as parents were tried.

The first winter of this "one hundred year epoch" brought temperatures below -30 degrees C. without snow cover and with icy winds. Many of the crosses brought from Dresden showed themselves to be not hardy enough in this climate. Of the 110 hybrids, only 14 with neither leaf nor flower bud damage remained. These became the standards for further propagation. Similar, severe selection has taken place with all their hybrids, therefore, the Seidel introductions are considered especially winter-hardy. Yearly, between 40 and 50,000 seedlings were pricked out, of that number, only a fraction showed sufficient hardiness.

In the cold winters, problems with understocks for grafting were also encountered. The understock used until this time, R. ponticum , showed itself as not sufficiently winter-hardy. T.J. Rudolf Seidel investigated using 'Cunningham's White' as an understock and found the scions made good growth and were considerably more frost-hardy. He recognized also the easier propagation of the understock through cuttings which helped with the economics of rhododendron culture. This all led to a "leap-forward" in propagation.

T.J. Seidel drew up several ground rules for his winter-hardy rhododendron hybrid breeding program:

— Never make unknown crosses;

— Always incorporate a hardy wild species;

— Employ the species as a seed parent;

— Exclude foreign (strange) pollen (bees);

— Pollinate successively on several consecutive days;

— First germinated and robust seedlings give superior results;

His breeding successes were recognized at many garden show exhibitions. At the World's Fair in Paris in 1900, he received a grand prize for his entries.

In 1904, he was assigned to direct a great horticultural exhibition in Düsseldorf. A special fast train with nine railroad cars travelled directly from Grüngräbchen to Düsseldorf. For this show, plants of up to three meters in height and width were selected and packed in peat moss and linen. They bloomed for three weeks at the exhibition grounds and at the show's close were sold.

After his death, his son, T.J. Hermann Seidel (1890-1957), took over the concern. He undertook the last crosses in 1938. Above all, today there are questions regarding the crosses of 'Hassan' x 'Genoveva', out of such combinations arose about fifteen partially, yet loosely, named novelties.

The rhododendron nursery still exists and is run by the grandson of T.J. Hermann Seidel. Many old shrubs from the "one hundred year epoch" are still standing and are powerful, mature specimens. Unfortunately, many varieties in the course of the years have been lost. The total number should run about 600. With certainty, however, about 350 named hybrids are evident in the catalog entries. The largest Seidel collection with about 110 hybrids is in the display garden of the teaching and research institute for horticulture at Bad Zwischenahn.

Attached is a short description of several of today's especially popular Seidel hybrids:

'Alfred' ('Everestianum' x 'Everestianum'), originated 1891, lilac with greenish-yellow spots, frilled, good blooming tendency.

'August' ('Everestianum' x 'Everestianum'), originated 1891, dark rose with yellow-green spots.

'Bibber' ('Mrs. Milner' x R. catawbiense ), originated 1900, bright, dark carmine-red.

'Bismarck' ('Viola' x R. catawbiense ), originated 1900, white-rose flowers with reddish-brown spots.

'Bismarck' Photo supplied by Erhard Moser

'Christian Schroder' ('Genoveva' x 'Hassan'), originated 1938, introduced 1964, purple-rose, yellowish spots.

'Cornelia Schroder' ('Genoveva' x 'Hassan'), originated 1938, introduced 1964, intense rose with blackish-red spots.

'Cosirria' ('Everestianum' x 'Everestianum'), originated 1893, carmine-rose with yellowish spots, frilled.

'Darius' ('Mrs. Milner' x R. smirnowii ), originated 1894, dark-rose with yellowish spots.

'Donar' ('Mrs. Milner' x R. smirnowii ), originated 1894, introduced 1914, bright carmine-rose with a white throat and dark red spots, frilled margin.

'Effner' ('Alfred' x 'Everestianum'), originated 1895, lilac with greenish-yellow spots.

'Eidam' ( R. japonicum var. japonicum x 'Alexander Adie'), originated 1895, white with rose tones, yellowish-brown spots.

'Erich' ('Mrs. Milner' x R. catawbiense 'Grandiflorum'), originated 1895, crimson-rose with ochre spots.

'Erich' Photo supplied by Erhard Moser

'Erika' ( R. japonicum var. japonicum x 'Alexander Adie'), originated 1895, bright carmine-rose with brownish spots.

'Erika' Photo supplied by Erhard Moser

'Flamme' ( R. catawbiense x 'Mira'), originated 1896, bright purple-violet with a bright center, yellowish-brown spots.

'Gerstäcker' (probably a R. caucasicum hybrid), originated before 1880, white with lilac tones, blackish-red spots.

'Gisela' ('Everestianum' x 'Boule de Neige'), originated 1905, bright lilac with dark borders and greenish spots.

'Hassan' ('Carl Mette' x R. catawbiense ), originated 1898, fiery carmine-red with brownish spots, very large flowered.

'Helene Schiffner' (parentage unknown), originated before 1890, pure white, for German situations not hardy enough, distinguished with a 1st prize 1893 in Chicago and an F.C.C. (RHS)

'Holger' ('Madame Linden' x 'Eggebrechtii'), introduced 1916, pale violet with large greenish flecks.

'Humboldt' ( R. catawbiense hybrid), originated about 1906, bright lilac-rose with blackish-red flecks.

'Humboldt' Photo supplied by Erhard Moser

'Kaulbach' ( R. catawbiense hybrid), originated about 1926, white with a lilac margin and yellowish-green spots.

'Ludwig Schroder' ('Genoveva' x 'Hassan'), originated about 1938, named 1988, purple-rose, dark red spots.

'Mexico' (parentage unknown), luminous bright carmine-rose, dark brown spots.

'Obergärtner Karl Baumann' ('Genoveva' x 'Hassan'), originated 1938, introduced 1964, lilac-rose, dark red spots.

'Oldewig' ( R. catawbiense hybrid), originated 1904, named 1912, ruby red with a bright center and red-brown spots.

'Omega' (parentage unknown), originated 1904, named 1912, rose with red-brown or yellow-green spots.

'Ortrud' (parentage unknown), originated 1904,named1912,delicate lilac with darker margins, brown buds.

'Parkfreude' ('Genoveva' x 'Hassan'), originated about 1938, named 1988, pure rose with dark red spots.

'Plüsch' ('Mrs. Milner' x R. catawbiense ), Seed of 1905, named 1913, bright carmine-rose, throat brighter with lighter brown spots.

'Renata' ('Annedore' x 'Mrs. Milner'), originated 1905, named 1915, shining dark crimson red, light brown spots.

'Rinaldo' ('Mrs. Milner' x R. smirnowii ), originated 1907, named 1915, shining carmine-red, with lighter bright green spots.

'Scharnhorst' ( R. catawbiense hybrid), originated 1908, named 1916.

Seidel Nr. 100 (seedling of 'Cunningham's White'), found about 1942, creamy-yellow, greenish spots.

Seidel Nr. 100 Photo supplied by Erhard Moser

'Ursula Seidel' (parentage unknown), shining rose with a bright center, yellowish spots.

'Ursula Seidel' Photo supplied by Erhard Moser

'Viola' ( R. caucasicum hybrid), originated before 1872, porcelain white, lilac buds.

'von Oheimb Woislowitz' ('Everestianum' x 'Carl Mette'), originated 1896, bright purple rose with yellowish spots, late blooming time.

Literature Register (in German)
Anonymous: A Contribution to the Development of Peat-Bed Cultures in the 19th Century; Rhododendron and Evergreen Leaved Trees, Bremen, 1988.

Schmalscheidt, W.: Rhododendron Breeding in Germany, Westerstede, 1980.

Schmalscheidt, W.: Rhododendron and Azalea Breeding in Germany, Westerstede, 1989.

Schroder, L.: The Contribution of the Family Seidel to the Development of Winter-Hardy Rhododendrons; in "Contributions to Wood-science", Berlin, 1989.

This article is a result of a collaboration between two Portland Chapter members. Dr. Dave Goheen encouraged Herr Moser to write and submit an article regarding rhododendron culture in East Germany and then was kind enough to translate the article for publication.