238 
THE NATIONAL NURSERYMAN 
Rhododendrons to be grown in this climate. It is well 
known that these old grafted plants often lose large 
branches from what gardeners call “canker,” and it is 
not impossible that the old plants killed in the Arboretum 
have been gradually failing for several years from the 
influence of the stock on which they had been grafted, 
and were therefore susceptible to extreme climatic con¬ 
ditions. This view is borne out by the fact that when 
plants of a particular kind were killed and others of the 
'same kind were not killed it was always the oldest and 
largest plants of the variety that suffered. It has gen¬ 
erally been supposed that it was the cross with R. arbor- 
eum and other Indian species which has made so many 
of the varieties of R. catawbiense tender in this climate, 
but some of the varieties which show in their bright red 
(lowers this influence, like Atrosanguineum, Charles 
Dickens, and II. W. Sargent are uninjured, while many 
of the pale-flowered kinds like Lady Grey Egerton, Mrs. 
II. S. Ilunnewell and Delicatissimum have been killed. 
The last is a hybrid between R. catawbiense and R. max¬ 
imum, and for the last thirty years has been considered 
one of the hardiest and most desirable of the Rhododen¬ 
drons which have been planted in New England. Plants 
of the following Catawbiense varieties have been killed 
in the Arboretum, but of the varieties marked with a 
star one or more, but not all the individuals in the collec¬ 
tion, have been killed. On many plants which have not 
otherwise suffered the buds have been killed or injured. 
* Adolf, Alarich, Albin, Alfred, *Atrorubrum, ‘Bismarck, 
Bluebell, ‘Butlerianum, Circe, Daniel, ‘Delicatissimum, 
‘Diana, Duchess of Connaught, Earl of Shannon, Egge, 
Elysium, Fee, *F. L. Ames, *F. B. Hayes, ‘Hanna Felix, 
Herkules, Jay Gould, ‘King of the Purples, ‘Lady Grey 
Egerton, Madame Wagner, ‘Marquis of Waterford, Mum, 
‘Mrs. Harry Ingersoll, Mrs. H. S. Ilunnewell, 
Mnemoisyne, ‘Prometheus, *R. S. Field, Salmonum 
roseum, Sir II. Haverlock. 
Rhododendron caucasicum. On the whole the differ¬ 
ent forms of R. caucasicum have come through the win¬ 
ter in comparatively good condition. The plants of the 
varieties Cleo and Ochroleucrum have been killed, and the 
flower-buds of a few others have suffered. The follow¬ 
ing varieties, however, are uninjured or have suffered 
only slightly: Boule de Neige, Coriaceum, Jacksonii and 
Mont Blanc. 
The Rainfall of Recent Years. Whatever may have 
been the cause of the death this spring of so many Rho¬ 
dodendrons the small rainfall of the last seven years 
must account, at least in part, for the generally poor con¬ 
dition of Rhododendrons in eastern Massachusetts for the 
deathin this part of the country of many old Oaks and 
other native trees in the woods, and for the great number 
of dead branches on many native Ash trees, even on 
young trees which should be healthy and vigorous. It 
is interesting, therefore, to study in this connection the 
statistics of the rainfall in recent years on the watershed 
of the Sudbury River in Massachusetts, about twenty 
miles from Boston. For the following figures the Arbor¬ 
etum is indebted to Mr. Desmond Fitzgerald of Brookline. 
During the years 1875-1903, inclusive, the average rain¬ 
fall on the Sudbury basin was 46.34 inches; from 1904- 
1914 the annual average rainfall was, however, only 
40.79 inches, or an annual deficit of 5.55 inches. During 
the seven years from 1908-1914 the annual average was 
only 39.24 inches, or an annual deficiency of 6.76 inches 
as compared with the period from 1875 to 1907, that is, 
the loss of rain in the past seven years is rather more than 
the entire rainfall of one normal year; and, moreover, in 
'these seven years there has not been a single year of nor¬ 
mal rainfall. 
Rhododendrons in the United States. In some years, 
when conditions are comparatively favorable, Rhododen¬ 
drons flourish in this climate; in other years when con¬ 
ditions are less favorable they suffer. Compared with 
■these plants as they grow in England and Scotland Rho¬ 
dodendrons are never really successful here. This is not 
a climate for Rhododendrons, that is for the sort of Rho¬ 
dodendrons European nurserymen usually propagate and 
send to this country. It is true some of them can be kept 
alive here for a great many years but they require special 
care. The soil in which they grow best has to be specially 
prepared for them; they require shelter from the sun of 
early spring, and a great deal of moisture. Of late years 
(they have suffered terribly from the attacks of the lace¬ 
wing fly which turns the leaves brown and makes them 
fall prematurely, thus weakening the plant. Rhododen¬ 
drons, like many other plants of the Heath Family, can¬ 
not grow in soil impregnated with lime; they are not 
hardy very far north of Boston, and south of Philadel¬ 
phia, except in the elevated regions of the interior, it is 
•too hot for them in summer, so that the region in the 
eastern states where these plants can be grown at all is 
not a large one. Here in eastern Massachusetts there are 
only four species of broad-leaved evergreen Rhododen¬ 
drons which are perfectly hardy; these are the native 
R. maximum, R. catawbiense from the high slopes of the 
southern Appalachian Mountains, R. carolinianum from 
the same region, and R. Smirnowii from the Caucasus, 
“THE MONTHLY SUMMARY OF COMMERCE AND FINANCE” FOR MAY 1915, GIVES THE FOLLOWING REPORT OF 
IMPORTS OF PLANTS, TREES, SHRUBS AND VINES. 
ARTICLES 
MAY- 
ELEVEN MONTHS ENDING MAY— 
1914 
1915 
1913 
1914 
1915 
Quantity 
Value 
Quantity 
Value 
Quantity 
Value 
Quantity 
Value 
Quantity 
Value 
Plants, trees, shrubs and vines : 
Bulbs, bulbous roots, or corms, cul¬ 
tivated for their flowers or foliage 
124 
2,534 
2,907 
109,922 
351 
2,448 
1,175 
55,422 
288,629 
1,823,198 
5,793 
1,357,570 
216,071 
2,091,142 
14,693 
1,456,274 
255,673 
2,374,820 
16,750 
1,336,000 
All other./ , 
Total. 
115,363 
59,045 
3,186,561 
3,562,109 
3,727,570 
