June 30,1881. ] JOURNAL OF HORTICULTURE AND COTTAGE GARDENER. 535 
the plants to grow so much more rapidly that with an inch or 
two of such material over the surface, beds and borders will be 
much more speedily filled than without. Indeed in hot seasons 
it often happens that on thin soils many beds and borders get 
thinner instead of filling up. Surely a mulching of even roughish 
materia], which would speedily become hid, is much better than 
this. We have gardened when without heavy watering, requiring 
much labour, or thick mulchings, such plants as Violas and Cal¬ 
ceolarias failed to grow at all, but an inch of decayed sifted 
manure alone over the surface, caused a luxuriant growth. 
The amount of water evaporated by trees against hot walls is 
often exhausting, and when this is accompanied by dryness in 
the soil much mischief follows. The attacks of red spider are 
oftener caused by aridity in the soil than the air. It is only, or 
chiefly, when trees are stinted of water that these do much 
Tig. 121. — jillenia trifoliata. (See page 529.) 
mischief. Luxuriant foliage seldom suffers ; stunted foliage is 
often destroyed. 
Mulching is preferable to watering even where water is plentiful 
and can be easily applied. Evaporation not only carries the 
water out of the soil, it carries the heat too. Water may even be 
frozen by its own evaporation under certain circumstances. Let 
anyone fill a pitcher with water on a hot day and wrap a towel 
round it. Place the pitcher in a shady but airy spot, and keep 
the towel constantly wet. Place a thermometer in the water, and 
you will be convinced that heat is carried away by evaporation. 
Now we seldom want to lower the heat in the soil. A cold soil is 
against the well-being of all plants that need the artificial help 
of glass houses or sunny walls. A cold soil will counteract the 
influence of warm air. Plants are benefited by warm air because 
it warms them, but it will, to a certain extent, fail in this if the 
ascending sap be cold ; and as evaporation from the soil produces 
cold, we ought to prefer mulching to watering, and when water¬ 
ing becomes a necessity mulching ought to follow in order to 
prevent the necessity of its re-application and the escape 
invaluable heat. 
It may seem a strange thing to advocate, but we say that water¬ 
ing should only be done in showery weather. It often happens 
that there are a few showery days consecutively, and yet not 
more than enough to damp the surface and reduce evaporation to 
a minimum. Then is the time to supply water. In hot weather 
artificial irrigation, unless it be very thoroughly done, is useless 
and worse, for the airsoon licks it up. When the air is damp, and 
yet the rainfall trifling, is the time to irrigate with the greatest 
success. At the same time irrigation when thoroughly done—that 
is, when the ground is flooded—is a great help on dry soil during 
drought, especially if mulching be applied immediately after. In 
the kitchen garden mowings from lawns and other short grass are 
of great value, but even when these are not available a loose layer 
of soil will do much to prevent evaporation. The free use of the 
hoe, whenever the soil is dry enough on the surface to be easily 
worked, will accomplish this to a great extent. 
So many excellent directions for watering plants in pots have 
appeared from time to time in the Journal it is not necessary to 
consider it particularly in this place. It may, however, be pointed 
out that mulching might more frequently be applied to plants in 
pots, especially in summer. Plants that are outside, and even 
those in houses, become dry at the root in a very short time, and 
often need water twice a day. This means a very rapid evapo¬ 
ration, and consequently a very low “ bottom heat.” In many 
instances a mulching of rich manure, accompanied by plunging 
in ashes, would do much to prevent this, and also feed the plants, 
thus proving doubly beneficial. Evaporation from pots cannot 
w r ell be avoided altogether, but glazed pots are better in this 
respect, and in others, than common ones. The idea that the 
porosity of the latter is beneficial is now an exploded theory. To 
prevent evaporation from pots as much as possible watering should 
be done whenever possible in summer time in the evening. 
For irrigation purposes, whether for a single pot or broad acres, 
rain water is best; after that comes pond, brook, or river water, 
and lastly spring. It is seldom that rain water is harmful, but it 
sometimes happens in the neighbourhood of chemical works that 
it is impregnated with noxious acids and other matters to an 
extent that makes its repeated use destructive to plants. Some¬ 
times brook and pond water contains iron to a hurtful extent; 
but this can be seen, for then the water makes a red deposit which 
betrays the presence of the iron. Brooks and rivers which flow 
through fertile districts are often positively enriching, but gene¬ 
rally speaking the plant food contained even in drain water from 
fertile fields is so small that it may be left out of account in 
estimating its value for garden purposes, although benefit has 
often been derived by meadow land from such waters. Some 
spring water is very suitable, but it often contains lime, and to 
many plants, Heath plants more especially, lime is very hurtful. 
When such waters are used for syringing it leaves a coating of 
lime on the leaves, fruit, &c., and this is very objectionable. 
Water containing lime may be made nearly pure by boiling it; 
even exposure to the air will cause much of the lime to settle. 
Where quantities of water are required large tanks are necessary 
if the water is to be improved by this means. In many instances 
lime is present in the form of bicarbonate ; in this state it is 
soluble, and does not separate from the water. If newly slaked 
lime or lime water is added the added lime seizes on part of the 
carbonic acid and the whole becomes carbonate of lime, which is 
insoluble and may be readily filtered from the water. Waters 
containing iron may be purified by exposure, and especially so if 
it is collected in large tanks, from which it can be run without 
disturbing the deposit. Generally speaking, however, it is far 
better and far cheaper in the end to build brick and cement 
tanks in the ground where it may be run ofE or pumped as 
required.— Single-handed. 
(To be continued.) 
COTTAGE GARDENING—MAKING THE MOST OF 
SPACE. 
A little garden sloping from the dwelling house southwards 
to the road, but raised above the level by a low stone edging and 
protected by light painted open wooden fencing. Looking upwards 
the house wall exhibits a crimson Boursault Rose tree in full 
blossom ; an Ayrshire climber close by, for the first time weakly 
even in foliage ; a Moorpark Apricot, formerly an ample bearer, 
now much shattered, and to be replaced in autumn by a profitable 
Plum. At the house door, approached by low steps, bushes of 
the old crimson China Rose, plants of common Musk (Mimulus 
moschatus), tufts of Echeveria with spikes of brilliant orange- 
coloured flowers, patches of Mignonette here, and there bushes 
