THE GARDENERS' CHRONICLE OF AMERICA 
247 
them. Numerous experiments show that there is some 
factor, neither food, air, water, nor temperature, which 
is operating to keep down these numbers. As it is put 
out of action by heating to 55.6 degrees C, or by traces of 
volatile antiseptics, and can be re-introduced by adding a 
little untreated soil, it is presumably biological, and the 
evidence shows that it consists in part at least of certain 
soil amoebae ; it is quite possible, of course, that other 
forms are involved as well. But whatever the detrimental 
organisms are, they impede the work of the organisms 
producing plant food in the soil. Fortunately, they are 
put out of action more easily than the useful organisms, 
so that we get the apparent paradox that any process 
fatal to life (but not too fatal) proves ultimately bene- 
ficial to the soil life, while any process beneficial to life 
proves ultimately harmful. Long frost, drought and heat, 
therefore, benefit the useful makers of plant food, while 
prolonged warmth, moisture and treatment with organic 
manures lead to deterioration, or to "sickness" as the 
practical man puts it. — The Gardeners' Chronicle (Eng- 
lish). 
CLEMATISES AND THEIR CULTIVATION 
A LTHUUGH these plants provide us with someof the 
-^*- most beautiful climbers that are hardy in this coun- 
try, their cultivation does not seem to be well understood. 
It is true that in some gardens Clematises will, when once 
planted, romp away in a delightful, free-and-easy man- 
ner, and give but little trouble to their owners, but in 
others any amount of coaxing will not induce them to do 
more than eke out a miserable existence. Even when 
they are established, their management appears to be but 
little understood, and for this reason we propose to draw 
attention to a few of the more salient points in their cul- 
tivation. 
Naturally, the soil in which they are to grow must be 
the first consideration, and here a lesson may be taken 
from the wild Clematis, or Traveller's Joy of our hedge- 
rows, a plant that is largely used as a stock on which to 
graft the many beautiful garden varieties that are in 
existence. This wild Clematis is usually found growing 
in the banks of hedgerows where thorough drainage is 
assured, and where its roots are shaded during the hot 
davs of summer from the direct rays of the sun. The 
character of the soil in such positions may, and frequently 
does, vary considerably, but almost invariably it will be 
found to contain a fairly large percentage of lime. This, 
then, may reasonably lead us to suppose that the Clema- 
tises of our gardens require soil that is exceptionally well 
drained, and which also contains a fair proportion of 
lime, a supposition that is borne out in practice. It does 
not seem to matter much what the bulk of the soil is, 
providing it is not excessively poor or abnormal in some 
other way, so long as it is deeply worked, well drained 
and contains a sufficiency of lime. A good form in which 
to add this substance is as old mortar ; a peck or two well 
mixed with the soil for each plant will not be too much. 
Planting, again, is another serious cultural detail, as 
on its successful completion success will largely depend. 
We have no doubt that one of the chief reasons for these 
plants dying off suddenly after they have apparently 
become established and are growing away freely is too 
deep planting, and possibly grafting instead of layering 
being the method of propagation. The roots should be 
carefully spread out, and ought not to be covered with 
more tlian two inches of soil, even less being sufficient 
where that of a clayey texture exists. The season for 
planting may be autumn or spring, but we prefer the lat- 
ter, the end of February or early IMarch being a good 
time. Growth at that season is about to commence, and 
the plants soon make themselves at home in the new soil. 
The positions in which Clematises are planted will, of 
course, depend largely on individual tastes, but if against 
a south wall, some provision for shading the soil over 
the roots during very hot weather should be made. A 
low-growing annual, such as Mignonette or Alyssum 
maritimum, may be sown over the roots for this pur- 
pose without fear of injuring the climbers. But Clema- 
tises look far better when allowed to scramble naturally 
over rustic poles or fences, or even over old evergreens 
or deciduous trees. 
Probably the least understood phase in the cultivation 
of Clematises is their pruning. In the majority of gar- 
dens they are allowed to follow their own sweet will, and 
this certainly is preferable to cutting them in a haphazard 
way and without full knowledge of their flowering period. 
Roughly, our garden Clematises may be divided into 
five sections, and if we know to which section a plant 
belongs, its pruning will be a simple matter. In the flor- 
ida section, i. e., varieties that have originated from the 
Japanese Clematis florida, we get white, blue and rose- 
purple flowers that open in May and June, Belle of Wok- 
ing being a notable example. The flowers of this set 
are borne on wood that was formed the previous year ; 
hence it will be readily seen that to cut away growth in 
autumn or spring would mean the destruction of many 
embryo flowers. Any thinning out of old wood that is 
necessary may be done immediately after flowering with- 
out any danger of cutting away incipient buds. Similar 
treatment should be given to those which have originated 
from C. patens, a native of China and Japan. These also 
flower in June, Fair Rosamond being a well-known mem- 
ber of this set. When we come to the large-flowered 
varieties of C. lanuginosa, which flower from July on- 
wards well into the autumn, we find they are produced 
mostly on young shoots, and the proper method of prun- 
ing these is to cut back fairly close all side shoots in 
February. A few of the main stems may also be cut 
to within one foot or two feet of the soil if desired ; this 
will induce young shoots to spring up from the base and 
so hide the bare stems that are rather characteristic of 
these large-flowered Clematises, of which Lord Nevill 
and Louis van Houtte are examples. The Jackmannii 
varieties need similar treatment ; but such early flowering 
species as montana and its variety rubra only need an 
occasional thinning of the old wood after flowering. — 
The Garden. 
A' 
THE JAPANESE YEW 
S the years pass the hardiness and value of this 
yew are confirmed by longer trial. There are 
three or four quite distinct forms. The one prob- 
ably most often seen here grows as a large, vase-shaped 
shrub with several spreading stems. Plants of this sort 
have been raised in the Arnold Arboretum from the seeds 
of tall forest trees collected by Professor Sargent in 
Hokkaido. Among these plants there are some which 
are beginning to develop a single leader and promise to 
grow into trees. There is another form which is grown 
in some American nurseries under the unpublished name 
of variety capitata. This is merely a seminal form which 
begins to grow with a single leader with treelike habit as 
soon as the seeds germinate. For those who want the 
Japanese yew in the form of a tree rather than a bush 
this form will best produce the desired results. Another 
bushy form with wide-spreading, nearly horizontal 
branches, which on plants thirty or forty years old often 
turn up at the ends and darker green leaves, is often seen 
in American gardens in which specimens only four or 
five feet high, Imt sometimes twenty feet in diameter are 
