34 
in frozen soil which makes it impossible to keep alive many of them 
in this country; and this is the reason why it is desirable here to water 
thoroughly Rhododendrons just before the ground freezes in the autumn. 
Rhododendrons imported from Europe suffer here from the stock on 
which they have been grafted. The almost universal custom among 
European nurserymen is to use Rhododendron ponticum as the stock 
for these plants because it is easily and quickly raised and readily 
grafted. R. ponticum is not at all hardy here, and there is little doubt 
that our want of success with Rhododendrons imported from Europe 
is due, in part at least, to the stock on which they have been grafted 
and that the gradual or sudden death here of large plants which have 
been uninjured by cold or drought for twenty or thirty years is due to 
this cause. 
The familiar Rhododendrons of New England gardens are so-called 
Catawbiense Hybrids and were raised in Europe many years ago by 
crossing R. catawbiense, a native of the highest summits of the Appa- 
lachian Mountains, with Himalayan species, notably the scarlet-flow- 
ered R. drboreum. It might be expected that plants obtained from 
these crosses would be hardy in proportion to the predominance of 
the American plant but, judging by the color of the flowers, this is 
not always true. Varieties like Atrosanguineum, Charles Dickens and 
H. W. Sargent, which have flowers as bright red as those of R. ar- 
boreum, are among the hardiest of all garden Rhododendrons; but 
varieties with white or pale flowers are more tender than those with 
rose pink or purple flowers which most closely show the influence of 
the Catawbiense parent; and unfortunately the varieties with light- 
colored flowers marked at the base with large brown or chocolate-col- 
ored blotches, like Sapho, are not at all hardy here. 
The hardiness of these hybrid Rhododendrons can only be determined 
by trial, although in selecting varieties for trial it is safe to assume 
that plants with broad leaves resembling those of R. catawbiense, like 
Everestianum, Mrs. C. S. Sargent, Roseum elegans, Henrietta Sargent, 
Catawbiense album, and all the varieties with light or dark purple 
flowers are likely to prove hardier than the plants with narrow leaves 
like Mrs. John Chitton. There are, of course, exceptions to such a 
rule. For example. Pink Pearl has broad leaves and is very tender; 
and Corner Waterer, although it has leaves as broad as those of any 
of these hybrids, usually suffers in winter and almost invariably loses 
its flower-buds. 
Persons who want to plant Catawbiense Hybrid Rhododendrons 
should take advantage of the knowledge which has been laboriously 
and expensively obtained abopt these plants at Wellesley on Mr. Hun- 
newell’s estate, where Rhododendrons have been tested on a large 
scale for sixty years, and here at the Arboretum where many of the 
hardiest kinds raised in England, Germany, and the United States will 
now soon be in flower. 
There are other evergreen Rhododendrons which are not as often 
cultivated here in Massachusetts as they might be. R. catawbiense it- 
self is perfectly hardy and none of its hybrids have handsomer foliage. 
It grows slowly, however, and never to a very large size, and the 
flowers are of a disagreeable purple rose color. 
Rhododendron maximum, which grows naturally as far north as 
southern New Hampshire, is a large plant sometimes treelike in habit, 
