632 
THE GARDENING WORLD 
August 5, 1905. 
dry in winter, besides permitting the superfluous 
moisture to readily drain away which you give 
them in summer. We fear that you have been 
killing the plants by too rich material, which 
serves to hold the moisture about the roots. 
When the latter get killed by stagnant moisture 
about them the plants fail to make satisfactory 
growth, or to keep in good condition. They 
will stand a fair supply of moisture in the summer, 
but should receive little, if any, in winter. 
Pink and Blue Hydrangea Flowers. 
We have a batch of Hydrangea hortensis which 
flowered pink last season. Now we have pink 
and blue on the same plant. Could you give anv 
reason for the blue flowers? The plants have all 
had the same treatment. (W. P., Hants.1 
There have been discussions concerning this 
phenomenon on both sides of the Atlantic, but 
neither from a practical nor. a scientific point of 
view has the question been properly answered. 
Some growers attribute it to a peaty soil. and 
others say it is due to iron in the soil. Some 
growers have also used weak solutions of alum 
in water in the watering of their plants, and find 
that the flowers come blue. Still another set of 
growers and thinkers consider that the blue 
colour is brought about bv growing the plants in 
shadv situations. All of these 'theories and 
opinions come to grief when tried experimentally 
if the flowers fail to give blue flowers. We have 
seen bushes with beautiful rich blue flowers one 
year, and in the following season the same plants 
gave merely pink flowers of the usual type, 
although they had received similar treatment as 
far as the growers could give it. The true cause 
of the flowers coming blue, however, remains to 
'be discovered. We require an experiment result¬ 
ing in blue flowers that can be repeated bv 
anyone who desires blue flowers. In some cases 
where we have seen bushes of some size grown 
in the open air not far from the sea shore a 
very large proportion of the flowers were blue 
upon the same plant which also had pink and 
paler shades. Possibly the vicinity of the sea, 
the nature of the soil, and the conditions conduce 
to the production of blue flowers, but all this 
remains to be scientifically proved. More than 
one of our native flowers varv with blossoms of 
different colours, even on the same niece of 
ground, and yet this variability has not been ex¬ 
plained. 
Small Moth on Plums. 
Can you say if the small moth sent herewith 
is likely to be the enemy which stripped the trees 
of foliage some weeks ago? If so, is there any 
means of destroying them? IS. W. B.) 
The insect' sent is the Small Ermine Moth 
(Hyponomeu-ta Padellus), which is often too 
plentiful on various trees belongng to the Rose 
family in the month of June. Apples, Pears, and 
more particularly Hawthorns come in for the 
attention of this small moth, whibh does a great 
amount of damage on account- of its numbers. At 
the present time you will reap some advantage 
by washing the trees with the garden engine, 
using merely clear water. If driven with some 
force upon the moths large numbers of them would 
he destroyed, but we are afraid that by this time 
the eggs will have been laid upon the trees for 
next year’s brood of caterpillars. It will do no 
harm, however, to wn.sh the trees by the method 
mentioned, and it will probably check the moth 
to some extent. Next year you should get a pail 
half-filled with water and paraffin, in which you 
may drop the webs that contain the caterpillars. 
This work should be done early, while the cater¬ 
pillars are yet quite small, because when they are 
about full grown they scatter themselves singly 
all over the tree, and are more troublesome to 
gather. By collecting them earlv you will also 
prevent damage to the foliage of the current year, 
and lessen the number of the likely broods for 
the following summer. 
Heavy Clay Soil. 
The soil of my garden is of heavy clay, and 
was until recently merely occupied with copse- 
wood. A small portion on the top seems good 
soil, hut the rest is merely clay. Ho-w can it be 
improved? (S. A. S-.) 
A good plan in dealing with your soil would 
be to skim off the surface of good soil, placing it 
in a heap by itself. Then a considerable layer of 
the clay should he taken out and burned in the 
usual way that clay is burned for ballast on rail- 
wav lines. Then the soil beneath this layer should 
be deeply dug or even trenched so that the wbol° 
depth of soil moved should be between 2ft. and 
5ft. in depth. The burnt clay can then be placed 
over that which has been trenched, and thoroughly 
mixed together by means of the spade or a good 
layer of the 'burnt clav could be laid on the tcqi 
of the unburnt material, and finallv a layer of 
the surface soil which was laid aside placed on 
the top of the burnt material, and all the three 
sorts mixed together by digging. The burnt clay 
will have the effect of making the soil open and 
porous, thus -preventing it from settling down 
into a solid mass a few months after it has been 
trenched. You would do well to bear in mind 
that the burnt clay constitutes merely a 
mechanical improvement of the soil, for the simple 
-reason that -all vegetable matter in it gets burned, 
so that it merely answers the purpose of rough 
sand or fine gravel. The top soil containing 
decaying vegetable matter should never be burned. 
What Plants Feed Upon. 
A letter in a recent issue of The Gardening 
World says that plants do not feed upon the 
soil to any great extent. Then what is the value 
of feeding the) ground with manure, etc. ? 
(H. A. L.) 
It may be well to remember that about half the 
dried weight of plants consists of carbon, which 
the plants collect from the atmosphere in the 
form of carbon dioxide, better known as carbonic 
acid gas. A very large portion of the- weight of 
plants consist s of water. In the case of manuring, 
the manures are far more bulky than the material 
in it furnishing plant food. The roots collect- 
mineral matters chiefly from the soil, and this 
bears a very small proportion to the weight o-f 
the soil in which the plants are growing. It is 
for the reason that -these mineral elements, or 
some of them, are frequentlv very scanty in soils 
where they have to be applied artificially. Besides 
the question of plant food, there is another and 
very important value in the manuring of soils, 
chiefly owing to the improvement brought about 
in a mechanical way. For instance, when we 
apply farmyard manure to a field or garden, this 
manure serves to -retain the moisture in the soil 
during summer, when moisture is very necessary 
for plant life and growth, especially if the rainfall 
is light. In such a case the manure would act 
as a store house of food and moisture. 
Sweet Peas Not Doing Well. 
I send you some Sweet Pea stems and foliage 
to see if you can find out what is the matter with 
them. Thev are only 2ft. high and flowering 
poorly. (A. F. H.l 
The specimens of Sweet Peas would seem to 
indicate several reasons for their poor condition. 
Some red spider on the foliage would account for 
the partial lack of colour. The stems would also 
seem to have been crowded. It is a common fault 
among gardeners to sow Peas of all kinds too 
thickly. The stems grow up -with a single thin 
shoot, and cannot- branch in -the same wav as thev 
would if sown at least lin. -apart- in -the lines. It 
is all a mistake to have practically several rows 
in the place that would be more profitably 
occupied 'by one. Those who like to have their 
Sweet Peas in the best form for exhibition pur¬ 
poses sow their seeds from 3in. to 6in. apart, 
thus leaving each plant, ample room to make 
strong growth a,nd to throw out branches. These 
side branches really keep up a succession of bloom 
long after the main stems have ceased flowering. 
Another reason we would suggest would be a 
lack of water at- certain times when the weather 
was very dry and hot. In most places this could 
hardly have been the complaint this year, although 
a fortnight’s dry weather is sufficient to affect the 
welfare of Sweet- Peas considerably. We would 
also suggest -that possibly you had grown Sweet 
Peas on the same soil in previous years, possibly 
on several successive occasions, if such is the 
case, it may be taken as a very good reason for 
the unsatisfactory condition of the Sweet Peas 
as the ground soon gets sick.of -them, unless deep 
trenching and manuring is practised annually. 
You will thus see that we have offered several 
suggestions for the betterment of your Sweef 
Peas, and you will recognise whether a-nv of these 
detrimental causes apply to your plants." 
Celosias in Beds, 
I have just seen some beautiful Celosias in a. 
London park. Have these been sown outside, or 
can they be reared like half-hardy annuals’ 
(A. C.) 
The plants you mention could not have been in 
bloom if sown in the open air, nor do we think 
they could have been reared like half-hardy 
annuals. They require more heat, especially in 
the early stages. They would practically require 
stove heat until they have reached a- certain size, 
when they can be kept cooler. The plants had 
no doubt been sown in -a stove temperature, potted 
off -singly, and shifted on as they required it 
until they commenced -to flower, and had then 
been planted in the open ground. 
Planting the White Lily, 
I intend getting some bulbs of the white Lily. 
What is the best -time to plant them? Any hints 
abo-ut t-h-eir requirements through the columns of 
your valuable paper will be appreciated. (J. 
Fiddes.) 
This Lily may be planted any time after the 
foliage has died away, but sufficiently early to 
have the bulbs in the ground before they com 
mence making fresh growth. The roots commence 
to grow again as soon as the autumn rains give 
them encouragement, so that the bulbs should at 
least be planted in August, or the first half of 
September. This particular Lily throws up a s;t 
of leaves in the autumn which last through the 
winter. Bearing these facts in mind, you should 
plant the bulbs sufficiently early before fresh 
growth has commenced. 
Trade Catalogues Received. 
^Amos Perry, Hardy Plant Farm, Winohmore 
Hill, London.—New Plants of Recent Introduc¬ 
tion ; also Perry’s Preliminarv List of Earlv 
Bulbs. 
T. Methven and Sons, 15, Princes Street and 
Leith Walk. Edinburgh.—Bulb List. 
Names of Plants. 
(G. F.) 1. Mimulus Lewisii; 2, Poterium cana- 
den=e : 3, Sidalcea m-ilvaeflora var. : 4 Mertensia 
sibiriea ; 5. Lvsimachia- ciliata; 6, Potent-ilia 
fruticosa; 7, Sidalcea Candida.—(A. L. D.) 1, 
Campanula porte-nschlagiana; 2, Campanula 
rhomboidalis ; 3. Veronica longifolia; 4, Francos 
ramosa; 5, Digitalis ambigua; 6. Digitalis lutea. 
-—(R. M.) 1, Spiraea Douglasii; 2, Spiraea 
lindleyana; 3, Cof oneast-er microphylla ; 4, Jas- 
minum officinale; 5, Buddleia glohosa-: 6, 
Veronica narvi flora.—-(E. F. W.) 1, Celsia- 
.aroturus; 2, N-epeta Glechoma variegata; 3, 
Agapant-hus umbella-tus variegatus; 4, Convol¬ 
vulus mauritanicus; 5, Mimulus glutinosus; 6, 
Phyllanlthius nivosus.—(W. G.)i 1. Veronica 
spicata-; 2. Linaria pallida : 3. Campanula pumila 
alba ; 4, Linaria alpina ; 5, Veronica pectinata : 
6, 'Sedwrn lyddum ; 7, Sedum -lupestre.—(A. F.) 
1. Oncidium sphacelat-um ; 2, Oucidium praetex- 
tum ; <3, Odontoglossum crispum.—(R. W.) 1, 
Asplenium font an um ; 2, Cvs-topteris fragilis: 
3, Cystopt-eris bulbifera; 4, Asplenium germani- 
cum : 5, Qryntogramme crispa ; 6. Osmund a 
regalis palustris.—(C. iH.) 1, Populus alba; 2, 
Populu -5 tremula; 3, Gleditsebia friacanthos : 4, 
Acer platanoides schwedleri ; 5, Acer pa-lmatum 
atropurpureum.—-(D. J.) 1. Campanula, la-tifolia 
alba; 2, Cimicafuga racemosa; 3, Hemerocallis 
fulva variegata.; 5, Veronica virginica japonica. 
—(F. Wallace) 1, Senecio Ivaempferi aureo-macu- 
latus; 2, Yucca aloifolia variegata; 3, Francoa 
appendiculata. 
