694 
THE GARDENING WORLD. 
July 2, 1892. 
CULTURE v. NATURE.* 
(i Concluded, from p. 678.) 
Chemistry has helped us much as to the due know¬ 
ledge of, and the true economy of, nitrogenous plant- 
foods or manures; but there is yet much to be done 
in the profitable application of chemical principles. 
Especially should the cultivator take note of the 
modern observations as to the storage or fixation of 
atmospheric nitrogen by bacteria that inhabit the 
root-nodules of many leguminose plants, such as 
Peas, Lupins, Clover, &c., for we may some day 
grow our own nitrogen far cheaper than we can buy 
it from Col. North, or the vendor of manures. 
The chemist tells us that his manures are better 
than farmyard manure, of which 80 per cent, con¬ 
sists of water, but he neglects to note the physical 
action of fresh farmyard manure on the soil, and the 
real truth here, as often elsewhere, no doubt lies 
between the two extremes, farmyard manure being 
the best bulky basis to be enriched with pure 
chemical manures for special crops. Thus for Grape¬ 
vines, or Potatos, or leguminose plants, the dominant 
fertilizer added should be potash ; for Wheat, Beet, 
&c., nitrates are best, and super-phosphates for 
Turnips and most of the Cabbage family. 
The manures especially to be used for any one 
crop depend in a great measure on the chemical 
elements in the soil on which it is grown. This is 
readily known by a fair analysis, our object being to 
supply the nitrates, or super-phosphates, or lime, or 
potash salts lacking, or not, in sufficient quantities in 
the natural soil. 
The chemist can tell us the food elements that 
gain access to the plant, and after the crop is har¬ 
vested his resultant analysis shows what has been 
stored up or developed ; but that which actually 
takes place inside the living plants — the vital 
chemistry, I may call it — is for the most part a 
mystery still. Hence, one of the mysteries of Nature 
is this, and it is one no chemist has as yet explained, 
viz., why . and how the vegetable products of the 
earth vary so enormously in character. From the 
same earth and the same atmospheric elements, and 
the same water, we obtain the most delicious of food 
or flavouring stuffs, the most potent of medicines, or 
the most fatal of poisons, and the magical labora¬ 
tories are the living plants themselves, Peach or 
Pear, grass or Grape-vine, Atropa or Aconite, or 
Digitalis, Eucalyptus or Cinchona, as the case may 
be. 
In a word, land culture, or rather, plant culture, 
actually creates wealth, whereas all other industries 
merely modify and make it more conveniently useful 
to our requirements. England is riot quite sure of 
her practical monopoly in coal and iron, but she is 
sure of her soil, the plant wealth or produce of 
which may be almost indefinitely increased for all 
time. 
Plants are really self-acting chemical laboratories, 
and may be economically considered as producing 
machines. The plant produces food and clothing 
for us unceasingly, and all we have to do is to start 
it going, and it works while we are sleeping. 
Variable Powers of Plants. 
One of the most remarkable of all physiological 
facts observable in a garden is, the variable powers 
possessed by different plants in the absorption and 
assimilation of nitrogenous manures. This power 
varies immensely in different individuals of the same 
species. Thus, if you sow- all the grains in the same 
ear of Wheat, or all the Peas out of the same pod, it 
by no means follows that their behaviour in this 
respect is identical or even nearly the same. The 
old simile, " as like as two Peas in a pod,” is not 
true. For some reason, at present not explainable, 
one or more of the Wheat grains, or of the Peas, will 
be more or less luxuriant than its neighbours, it will 
grow faster, and it will prove more fertile, and as a 
rule this is owing to its enhanced powers of feeding 
and assimilation, that is to say, in some occult 
manner it makes a better use of its environment than 
its relations, and so becomes what the gardener calls 
a better variety both as a grower and producer. It 
is the observation of this variability that has led to 
■■ selection ” as one of the most potent phases of im¬ 
provement by cultivation. 
We have all heard the story of the gardener who 
inquired of the philosopher "why the weeds grew 
* A paper prepared by Mr. F. W. Burbidgb, Curator, 
Botanic Garden, Trinity College, Dublin, and read, in his 
absence, at the meeting of the Horticultural Club, Hotel 
Windsor, Tuesday, June 7. 
more rampant in his garden than the flowers.” 
“ You see,” said the wise man, " Nature is mother to 
the weeds, but she is only stepmother to the 
flowers.” Even this view is not ever and always 
right, because we know now (as Herbert told us long 
ago) that certain species of plants are not always 
happiest, i.e., most luxuriant and re-productive in 
their native habitats For example, we can take the 
Scotch Thistle or the English Sweet Briar, both 
great nuisances to the Australian settlers; or the 
south European Cardoon, which has completely 
overrun some of the great Pampas or plains of 
South- America, to the exclusion of their native 
vegetation. 
Observation proves to us that some plants have a 
very wide range of climatic adaptability, such as the 
examples to which we have just alluded ; while on 
the other hand we have plants that rarely do well 
except in their native places, such as the Durian 
(Durio zebethinus) and the Mangosteen (Garcinia 
mangostana). Again we have the Chinese Orchid 
(Phaius grandifolius) that is naturalised as if wild 
in Jamaica, and the matted and luxuriant Reed 
Orchid of Singapore (Bromheadia palustris), or the 
lovely Lycopodium cernuum that practically defies 
cultivation. 
Physical Structure of Plants. 
Gardening is essentially an art of trying experi¬ 
ments, and this is so in part because our physical 
knowledge of plants is so poor. In a word, we have 
not yet learned that the laws of a plant’s physical 
structure, formed as they are by climate, &c., must 
necessarily govern, to a great extent, its cultural re¬ 
quirements. Broadly speaking, gardeners know 
that a thickened epidermis (as in Cacti and succulent 
plants generally) means that they thrive in a dry 
atmosphere, and in sunshine rather than in shade. 
The same is true of plants with thick woolly, or hairy 
or powdered foliage. On the other hand, Ferns of a 
thin translucent texture, or delicate-leaved plants 
with a thin epiderm full of stomata, require a 
moisture-laden atmosphere, and more or less shade ; 
but there are thousands of cases where we can a 
priori know nothing of a plant’s powers of resisting 
heat or cold, sun or shade, moisture or draught, 
except by actual experiment. You may collect two 
plants from a mountain-side, 10,000 feet or so in 
altitude, near the equator, and one will be perfectly 
hardy in northern Europe, and the other will die at 
the first touch of frost. Why this is we do not fully 
know ; but we may at least keep the question in our 
minds, and hope some day to solve the problem. 
I have said, that a priori we can never be perfectly 
certain of the temperatures or soils most suitable for 
any one plant unless we are carefully told how it 
exists in a state of Nature. Even when this informa¬ 
tion is given, it by no means follows that our imita¬ 
tion of native conditions will prove to be best suited 
to the plant. As we have said, native conditions are 
not invariably those best for some plants, inasmuch 
as they have thriven and increased better when 
introduced elsewhere. A good gardener is in an 
analogous position to a good physician, and will 
prescribe for a plant quite as reasonably as does the 
physician for a patient totally unknown to him. 
It was until quite recently thought that unless a 
substance was in a soluble state, i.e , soluble in water 
in the soil, it could not be utilised by the plant. 
This view is now modified, since it has been found 
that roots themselves, and especially their growing 
points, secrete or rather exude an acid ferment that 
renders soluble or permeable many substances not 
actually soluble or dissolvable in water alone. In 
this way I have seen the underground stolons of 
"Couch-grass” (Triticum repens) bore straight 
through Potatos and other fleshy tubers or stems ; 
and only the other day saw a shoot of Tropaeolum 
polyphyllum that had come up through a brick that 
had happened to be in its way. In a word, the old 
story that roots follow the line of least resistance is 
not always, even if often, true. 
I am far from feeling that I have exhausted this 
great subject, rather do I feel that I have merely 
touched the hem or fringe of the question in a ten¬ 
tative kind of way. "Culture versus Nature” is 
really a question to be solved by each one of us in 
our own gardens, and I sincerely hope that these 
observations may be a help rather than a hindrance 
to our so doing.— F. IV. Burbidge. 
Summary. 
In conclusion it may be well to formulate a few of 
the observations in this paper, so as to facilitate 
discussion—that very life-essence of the reading of 
papers. 
1. Cultivation is the most convenient method of 
enabling us to obtain crops in any particular condi¬ 
tion, place, and at the time when most desired. 
2. From the human point of view culture improves 
Nature, even at her best ; but from the purely 
natural point of view, this is not always the case. 
3. Culture is often best, easiest, and most profit¬ 
able in climates similar, even if not actually the 
same, as those where the plants are naturally found. 
In any case, suitability of soil and climate other 
things, such as cost of land, skilled labour, and 
manures being equal) are the most essential points 
in profitable cultivation. 
4. Prejudice in plant culture is not to be tolerated. 
The golden rule is to try experiments in planting 
under different conditions, and be guided by the 
evidence of the plants themselves. 
5. Human desires are mainly for succulent vege¬ 
tative growths ; large pulpy or sugary fruits or seeds 
in varying stages, as used for food, and flowers for 
use or ornament. But Nature’s great aim and object 
on the other hand, is a crop of fertile seeds to per¬ 
petuate and strengthen the race. 
6 . Seeing that in nearly every garden there exist 
different conditions of soil, climate, shelter, aspect, 
&c , it naturally follows that we cannot dogmatise 
on cultural methods. Even in the same garden, 
methods of culture must necessarily vary just as do 
the seasons themselves. 
7. Successful cultivation is at its best a matter of 
accurate observation, and careful experiment, fol¬ 
lowed by logical reasoning powers. 
8. Gardening, then, is not altogether an empirical 
art, although best learned or taught by practice in 
good gardens, in addition to good reading or lectures 
and demonstrations, i.e., practice and well-directed 
study are better than is either alone. 
g. Wild plants are improved, humanly speaking, 
by culture ; so, on the other hand, cultivated plants, 
as a rule, either die out or revert to their type species 
if neglected or relegated to a wild state. 
10. Note the nitrogen fixing or accumulating 
power of leguminose plants. 
11. Chemical analysis is not a certain guide to the 
vital action inside the living plant. 
12. Plants may often be economically regarded as 
mere producing machines, and selection as an im¬ 
proving factor depends on some seedlings being better 
able to use up nitrogenous matter quickly than are 
others from the same parent. 
13. Some plants have proved more luxuriant and 
prolific in other countries than their own, showing 
that plants in their native habitat are not always, 
even if often, at their best. 
14. A priori we may have no evidence of a plant’s 
elasticity, either under climatic variations or cultiva¬ 
tion, but reasoning by analogy, and the instincts 
possessed by the gardener are generally enough to 
solve the problem. 
15. Physical structure and the general appearance 
of plants alike suggest to experts a course of treat¬ 
ment, just as they would to a physician who had to 
treat a patient to whom he could not say a word. 
16. Roots are now known to have the power of 
dissolving substances by their acid secreticns and 
exudations that are not dissolvable in water. 
17. The main point is, for the cultivator to ascer¬ 
tain the dominant desires, so to speak, of the plants 
to be grown. Lime-loving plants are often peat- 
haters, and vice versa. A good analysis of soil will 
be a broad guide as to the dominant manures or 
other additions requisite for particular crops. Farm¬ 
yard manure, strengthened with chemical manures, 
is generally better than either alone, as we here 
secure the maximum of mechanical or physical, as 
well as of chemical stimulus.— F. IF. B. 
-—S»- 
SMITH’S SNOW-WHITE CLEMATIS 
JACKMANNI. 
Looking over a friend's garden a few days ago, I was 
much impressed with the sterling good qualities of 
this grand Clematis. It is a genuine white Jack- 
manni, with even better-shaped flowers than the type, 
and the blooms, pure satiny white, haveplenty of sub¬ 
stance. And what a bloomer it is ! Not even Jack- 
manni itself is more floriferous. Those who have it 
not should certainly get it if they want a good thing 
in the Clematis way.— X. 
