Rhododendrons in Germany and in the Bremen Test Garden
Bremen Rhododendron, Gesellschaft Bremen-Horn
In Germany, only two rhododendron species are found. In the Alps we find two species, R. ferrugineum and R. hirsutum. They are found even at an altitude of 2300 m. Though they are magnificent plants in their primeval conditions, they are only little used in garden culture. But the more showy hybrids and a number of Oriental species are important. In North Western Germany with its Atlantic climate the conditions for the growth of rhododendrons are particularly favorable.
When you as a visitor come to Germany by ship, in the sea-ports of Hamburg and Bremen you will soon become aware of a great number of rhododendrons in the gardens and parks.
About the middle of May, which is usually the blooming-time of the rhododendrons, the visitor will note that the largest plants are mostly R. catawbiense hybrids. A very great part of the large flowered hybrids are derived from R. catawbiense. This species, having been introduced to Europe in the beginning of the 19th century, has all the good qualities of easy cultivating in our comparatively rough climate that is more equable, to the many East-Asia species and hybrids. The most frequently cultivated hybrids in North Western Germany under all circumstances must be hardy, and the following are always successful: 'Album Novum', 'Cunningham's White', 'Gomer Waterer', 'Mme. Carvalho', 'Catharine van Tol', 'Duke of York', 'Van der Hoop', 'Dr. H. C. Dresselhuys', 'Van Weerden Poelman', 'Charles Dickens', 'Edward S. Rand', 'Parson's Gloriosum', 'Caractacus', 'Everestianum', 'Purpureum Grandifiorum', 'Catawbiense Grandifiorum', 'Catawbiense Boursault', 'Fastuosum Plenum', 'Lee's Dark Purple', 'Dr. V. H. Rutgers'.
Of this group no less than 12 are catawbiense hybrids. Furthermore, the hybridizations of the firm Seidel Grungrabchen are favorite throughout Germany, because of their special hardiness in winter. Some of those varieties are: 'Allah', 'Emma', 'Oldewig', 'Alfred', 'Erika', 'Raphael', 'Bibber', 'Eidam', 'Gudrun', 'Daisy', 'Holger', 'Genoveva', 'Effner', 'Humboldt', and 'Leopold'.
Besides R. smirnowii and R. metternichii Seidel mainly used R. catawbiense as a parent in his crosses. However weaker hybrids of the griffithianum, arboreum class a.s.o. are planted on particularly sheltered places.
America F. D. Godman Jacksonii Britannia Mrs. P. den Ouden Kate Waterer James Marshall Brooks Lady Annette de Trafford Pink Pearl William Austin Louis Pasteur Prof. Hugo de Vries Prof. F. Bettex Mme. Masson Souvenir de Dr. S. Endtz John Walter Boule de Neige Mrs. R. S. Holford
During the last twenty to thirty years many hundreds of species have been cultivated of which I only shall list the most important ones:
R. impeditum R. augustinii R. schlippenbachii R. orbiculare R. fortunei R. vaseyi R. keiskei R. makinoi R. williamsianum R. degronianum R. oreotrephes R. camtschaticum R. cantabile R. rigidum
Also hybrids of low growing species as R. repens and R. williamsianum are being hybridized and placed on the market.
As to the Azaleas, the Ghent hybrids partly derived from American species are chosen very often.
Besides the molle and occidentale hybrids many sorts of Japanese Azaleas are cultivated. Some of the best known sorts are: 'Hatsugiri', 'Hinomayo', 'Hinodegiri', 'Alice', 'Betty', and 'Vuykiana'.
In Germany there are two larger districts of cultivation, one of those in Saxony and the other in Oldenburg with its wide moor territories. Since being so near the nursery of Oldenburg and having such favorable climatic conditions, the Rhododendron Park was laid out in Bremen. It has an area of 15 ha and is part of the Botanic Garden (34 ha).
Beneath a thin stand of trees about 50 years old oaks, beeches, birches and ashes the rhododendrons and azaleas have been planted together in thickets according to modern landscape principles. Where it was possible, the single sorts and groups of species are planted thinly so that the visitor gets a clear view of the garden. In a separate planting the hybrids have been arranged according to their colors and the species according to their series.
The test of the sorts is made jointly with the nurseries by the R. Society which has given itself the following aims:
- To increase growing of rhododendron and evergreens.
- To work jointly with all who engage in rhododendron culture.
- To promote the Rhododendron Park in Bremen-Horn and similar test gardens.
- To edit yearbooks or periodical notices about topics of rhododendron cultivation.
- To arrange rhododendron shows.
- To accomplish ratings of new sorts together with hybridizations and gardeners.