146 



GARDENERS' CHRONICLE 



Rhododendrons and Azaleas in die Garden 



FRANK B. MEYER 



OF rliorodendrons there are more thnn two hun- 

 dred species. Most of these have heen found upon 

 the Ihnialayas and the mountains of southwest- 

 ern and western China, where have recently been dis- 

 covered very many new species, some of superior loveh- 

 ness. One or two species are native to northern China. 

 two to central Japan, one to the Pacific states of North 



Azalea hilca. Flame Acalea. (Courtesy of Harlan P. Kclsey) 



America and five to the Atlantic, two to the mountains 

 of centra! Europe and four to the Caucasus. 



The ordinary reference to rhododendrons means some 

 of the hybrids, the "handsomest of all broad-leaved 

 flowering evergreens," so desirable because of their hand- 

 someness, but in the eastern and northern parts of the 

 United States generally not permanent or at least not 

 satisfactory in their behavior. The explanation 

 of this can be made most conveniently by cjuot- 

 ing from Ernest H. Wilson's remarkalile article 

 that appeared in the Garden Magazine about five 

 vears ago. Centering largely around the Arnold 

 Arboretum and written with New England con- 

 ditions in view it contains mention of difficulties 

 that can be discounted somewhat in a climate 

 not so rigorous. 



"The present day race of evergreen rhododen- 

 drons is essentially an English product and to 

 better understand the subject let us brietly in- 

 ve.=itigate its early history. No rhododendron is 

 native of the I'.ritish Isles and the first of the 

 evergreen section to be introduced was R. maxi- 

 mum, indigenous to eastern Xorth .Xnurica, 

 which flowered for the first time in London in 

 1756. A few years later (1763) R. ponticum 

 was introduced and was followed in 180.3 by A'. 

 caucasictim. The .American A', rata^chinisr 

 was introduced by John Eraser aliout ISW, and 

 was common in gardens in 1838. 1 lere are the 

 beginnings of the rhododendron cult in England. 

 Of these four species only two (R. ponliniiit 

 and R. catinvhiense) have played a major part. 



"As a breeder R. ponticum has been the great- 

 est asset and although its color is not good it 



has proved cxtraor<Hn;ii"ily adrii)tahk' in Great Britain and 

 Ireland. This species grows wild in southern Spain and 

 reappears in .\sia Minor, in Syria and in the warmer 

 parts of the Caucasus. These regions enjoy a much 

 warmer climate than does New England and from our 

 viewpoint it is a tender species and unsuitable as a 

 breeder. Also, for the same reason, it ought not to be 

 used as a stock for grafting; yet, unfortunately, it is the 

 stock so employed. An appreciation of these facts ex- 

 plains in a large measure the doubtful hardiness and un- 

 certainty of the present-day race of rhododendrons, since 

 the blood of this tender species enters largely into the 

 majority of the varieties. 



"In the matter of hardiness the American R. cataiv- 

 biense has been the greatest of all gifts in the realm of 

 rhododendron and the hardiness of our present-day race 

 depends almost solely upon the dominant influence of the 

 blood of this species. 



"Rhndodcndron caiicasiciiin is a native of the higher 

 Caucasus peaks and should be of much value to us since 

 it is quite hardy in New England. Unfortunately it has 

 been very little used by hybridists ; but such offspring as 

 Boiile de Neige, Coriaceimi, Jacksonii and Mont Blanc 

 are very .satisfactory plants in the Arnold Arboretum. 



"Our native R. nmximnm, though the first species in- 

 troduced to cultivation, has played a very unimportant 

 part in the evolution of present-day rhododendrons. In 

 a manner it has been disappointing ; yet it is questionable 

 if it has had a fair chance. To us its hardiness and late 

 flowering are qualities of vast import.'' 



Of the hybrids those that are most adaptal)le to the 

 climate of Boston are : with red flowers, Atrosanguincwin 

 (very early), Charles Dickens, H. W. Sargent (late); 

 with reddish flowers, Caractacus; with rose-colored 

 flowers, Rosciim elcgaiis. Lady Armstrong; with pink 

 flowers, Mrs. Charles Sargent, Henrietta Sargent: with 

 dark purple flowers, Evcrcxtianinn; with w-hite or nearly 

 white flowers. Album clegans, Album granditlonim. 

 Catazvbicnsc (very early). But near Pbiladeliihia at 



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h'hiulinlnulrnii calau'bictise. Catawba Rhododendron. 

 {Courtesy of Harlan P. Kelsey) 



