April 26, 1883. ] 
JOURNAL OF HORTICULTURE AND COTTAGE GARDENER. 
333 
26th 
Tn 
Iloy.nl Society at 4.30 P.M. 
27ch 
F 
Quekett Club at 8 P.M. 
28th 
S 
Royal Botanic Society at 3.45 P.M. 
29th 
SUN 
Rogation Sunday. 
30th 
M 
1st 
TU 
2nd 
W 
Rochdale Auricula Show. 
BELGIAN AND ENGLISH LEAF SOIL. 
^£^^^^^EABLY everyone who receives such plants 
. ag Camellias and Azaleas from Belgium 
is more or less surprised by the luxuri¬ 
ance of their growth and the great 
• masses of healthy roots that crowd the 
soil the P°t s * This is obviously a 
mixture of leaf soil and sand chiefly. Some¬ 
times there may be a little peat and a sus¬ 
picion of light loam, but decayed leaves form 
the basis of the compost; and that it is well 
adapted to the requirements of those plants with 
many others, none can dispute who has seen the quick 
and admirable manner in which they are grown. It 
is equally evident, too, to persons who endeavour to 
imitate the compost in which the plants arrive, and 
use leaf soil principally in repotting them, that they 
no longer flourish as they did before, however carefully 
they may have been tended in ocher respects, such as 
watering, assigning them positions, and placing them 
under conditions the most favourable for their well¬ 
being. The fault rests in the soil, and the conclusion 
is arrived at that Belgian and English leaf soil are 
essentially different in their constituents ; but in what 
particular respect they differ, and why the foreign pro¬ 
duct is so good and the English so inferior, has not 
yet been made so plain as is desirable to cultivators in 
this country. Although I am not quite certain I can 
make a matter perfectly clear that is as yet obscure, 
something may perhaps be said that will lead to the 
subject being better understood, and without question 
much more valuable leaf soil may be obtained in Eng¬ 
land than that which is commonly used. 
Some gardeners have become so dissatisfied with leaf 
soil that they have relinquished its use in plant culture, 
considering it worthless. The material at their dis¬ 
posal may have been worthless, just as bad bread may 
be even worse than useless; but neither true bread nor 
true leaf soil merits such an opprobrious designation. 
The truth of the matter appears to be this, that Nature 
makes good leaf soil, but man by his method of pre¬ 
paring it spoils it. That is rather a bold statement, 
but I am prepared to prove its accuracy. 
First, however, it may be well to glance at the nature 
of leaf soil. It may be described under the term 
“ humus.” Those gardeners who denounce this matter 
as useless may have a certain amount of supporting 
testimony from some agricultural chemists. Even 
Liebig has written disparagingly of humus, and only 
considered it useful, if useful at all, in the earliest 
stage of a plant’s growth ; but if all the scientific 
persons in the world were #to demonstrate the absence 
of fertilising constituents in leaf soil, I should with all 
due respect decidedly prefer the evidence of the mag¬ 
nificent Azaleas I saw at Ghent last week. These are 
not young plants in the first flush of youthful vigour ; 
on the contrary, many of them may be described as 
matured trees, yet the “food for young plants” sus¬ 
tains them in a manner in which the best specimens 
grown in English peat cannot be properly placed in 
comparison. So far from leaf soil possessing little or 
no value, it is the very foundation of the success of the 
Belgian cultivators, and has more than anything else 
contributed to their prosperity and the world-wide fame 
of their establishments. Leaf soil, then, or humus is 
decayed vegetable fibre, that undoubtedly contains fer¬ 
tilising properties, because amongst other things it 
slowly and steadily generates carbonic acid, and in 
addition it possesses a greater power of absorbing water 
than any other kind of soil, a circumstance of no small 
value for cultural purposes. 
It is very desirable that a clear conception of the 
nature of humus be understood, and, so far as I know, 
the subject has nowhere been so thoroughly, fairly, and 
exhaustively discussed as in a series of remarkable 
articles in the last volume of this Journal by an accom¬ 
plished gentleman whose death was announced last 
week—Major-General Scott, C.D., F.R.S. The results 
of that searching examination of the subject was sum¬ 
marised as follows :—Humus is valuable, because “ 1, 
as an absorbent of moisture, which materially increases 
the fruitfulness of a soil; 2, by attracting and physi¬ 
cally fixing ammonia, which would otherwise be washed 
away; 3, by chemically fixing ammonia by the aid of 
the acids which are generated as its decomposition 
proceeds ; 4, by providing a long-continued, if feeble, 
supply of carbonic acid, which helps to distribute the 
phosphates, &c., which are imperfectly disseminated 
through a soil; 5, by assisting, through the disinte¬ 
grating influence of the carbonic acid which it gene¬ 
rates, in breaking down hard insoluble substances con¬ 
taining potash and silicic acid, &c. ; 6, by supplying 
carbonic acid to bring about the transference into the 
organism of the plant of the food with which the root¬ 
lets come into contact.” 
Having shown the value of humus—leaf soil, its 
preparation next demands attention. This is a matter 
of infinitely greater importance than the majority of 
cultivators conceive. For years I have been endeavour¬ 
ing to find out the essential difference between Belgian 
and English leaf soil, and at length after several visits 
to Belgium I have succeeded in my object. Two or 
three years ago. in a conversation on leaf soil and 
Azaleas with Mr. Barron at Chiswick, he observed, 
“ Leaves for leaf mould should never be heated.” That 
remark was not lost. As soon as possible Azaleas and 
Camellias that had been struggling for life in prepared 
—that is, spoiled leaf soil, were potted in some that 
Nature had made—that is, where the leaves had de¬ 
cayed, not fermented. The result was almost magical, 
and a new lease of life was given to the plants, which 
commenced rooting in the fresh compost in the most 
satisfactory manner, the leaves in both cases having 
been gathered from the same trees. Quite recently I 
have had the pleasure of discussing this subject with 
one of the most experienced of Belgian horticulturists 
—Mr. Van Geert of Antwerp, and he not only urged 
the absolute necessity of using naturally decayed, not 
fermented, leaves in the form of soil, but alluded to 
No 148.—VOL. VI., TlIIRD SlBIES. 
No. 1801 —Vol. LXIX., Old Series. 
