510 
THE GARDENING WORLD 
April 11, 1891. 
The Amateurs’ Garden. 
SEASONABLE WORK in the GARDEN. 
Psychotria jasminiflora.—This is also known as 
Gloneria jasminiflora. Owing to its peculiar nature 
and the leathery character of its leaves it may be 
grown either in the stove or greenhouse. Some culti¬ 
vators may not be aware of the latter fact; but it may 
even be planted out and trained against a wall, where 
it will produce a large quantity of bloom. When 
grown in the stove it enjoys a drier atmosphere than 
stove plants generally do. Those who possess it may 
do well to remember these facts. 
StepLanotis grandiflora.—The flower buds on 
autumn-produced wood will now be opening. Syring¬ 
ing must, however, be continued to keep down insect 
pests and maintain the health of the plants. The 
flowers themselves will take no harm at being wetted, 
so long as the water used is clean. 
"Winter-flowering Plants. —Cuttings of several 
things, such as Centropogon Lucyanus, Begonia in- 
signis, B. semperflorens and its fine varieties, Euphorbia 
fulgens (E. jacquinireflora), Eranthemum nervosum, 
and others may now be inserted, with the view of 
growing them on for winter flowering. If placed in 
bottom heat they will soon form roots, when they 
should be potted off singly and grown on vigorously. 
Green Fly and Eed Spider, &c.—Means should 
be taken in the early part of the season to keep down 
insect pests, which iucrease rapidly with the rise of 
temperature. Furthermore, if severely handled when 
they make their first appearance, it takes them a long 
time to regain the lost ground, for their numbers are 
few at this early period. This applies particularly to 
green-fly, while thrip and red-spider are always present 
and ready to increase when circumstances favour them. 
Frequent light fumigation and a free use of the syringe 
will keep them down. 
Show and Fancy Pelargoniums.—Considerable 
attention must now be given to this class of plants in 
the way of tying down, so as to admit light and air 
amongst the shoots, and prevent them from getting 
drawn. The pots are now well filled with roots, and 
large supplies of water are necessary to keep up the 
vigour of the plants, and maintain the foliage in a 
healthy condition. Full exposure to light must not be 
overlooked ; and proper attention to ventilation is 
essential to success. 
Camellias.—Those that are planted out in certain 
houses must of a necessity conform to the same in 
matter of temperature, ventilation, and the time of 
making their growth. Camellias in pots, however, can 
be grown so as to be in bloom at particular periods. 
Those now out of bloom should be transferred to a 
house with a close moist atmosphere and a moderately 
high temperature in order to encourage fresh growth. 
"Wood that is ripened early will produce flowers at a 
correspondingly early period next year. 
Early Figs.—The fruit on pot plants started in 
November will now be approaching maturity, and when 
such is the case, a drier atmosphere must be maintained, 
and more ventilation given, otherwise the fruit will be 
of poor quality as regards flavour. A good plan would 
be to expose the fruit as much as possible, not merely 
to light, but to direct sunshine, where this can be 
managed. Fruit so ripened would prove very acceptable 
on the dessert table at this early period of the year, 
while fruit of all kinds is scarce. 
The Orchard House.—The trees in this house 
will now be mostly out of bloom, and if such is the 
case, it is advisable to fumigate on two successive 
evenings when the weather is calm, in order to destroy 
the newly founded colonies of aphides. Attend to 
watering so that the roots may always be in a moderately 
moist medium. More abundant supplies will, however, 
be necessary as the season advances and the foliage 
becomes more plentiful. The trees must not, however, 
be starved even at this early period, or it will cause 
the flowers and young shoots to drop. 
Vegetable Seeds, &c.—A sowing should now be 
made of such things as Vegetable Marrows, Ridge Cu¬ 
cumbers, and Capsicums, for planting out-of-doors when 
the weather becomes suitable. The earliest batch of 
Celery, if not already accomplished, should be pricked 
off into boxes, and a sowing for late work made. Peas 
that have been raised in pots, boxes, or turfs, should 
be still further hardened off by standing them under a 
south aspect wall before finally transferring them to 
the open ground. Stake immediately after planting. 
Annuals.—Continue the sowing of the more hardy 
sorts, not forgetting the ornamental grasses, such as 
Briza minor, B. maxima, Eragrostis elegans, and the 
Hare’s Tail (Lagurus ovatus). In the sowing of 
annuals on borders, care should be taken to properly 
arrange the kinds with regard both to height and 
harmony of colour. 
HELLEBORUS COLCHICUS. 
Of the seedling forms of this fine Hellebore, if not 
much of praise can be given, at least they show better 
variety of colouring, and some near approach to pure 
white, which is a most desirable hue to find in this 
Lenten Rose, so called. The original form, colchicus, 
is still the best coloured of all the dark-flowered forms, 
but it is in gardens, as a consequence, somewhat incon¬ 
spicuous. All the same,, there can be no question that, 
blooming so freely as it does, when other hardy plants 
have few leaves much less bloom on them, it deserves 
wider cultivation than now obtains. 
It is said of the hybrid or garden varieties that when 
flowers are cut and put into water they soon fade ; on 
the other hand, the type blooms keep for a long time. 
It would therefore seem as if the cross-breeding needful 
to produce variety in flower colour had to some extent 
weakened the wood or growth and caused it to be more 
flaccid. The plants of all kinds, and of the type 
especially, propagate rapidly by division, and single 
crowns, if cared for and grown in good soil, will speedily 
develop into big clumps. It is when so found that the 
Hellebore proves really attractive, for not only is the 
foliage fine and effective, but the clusters of bloom 
stems make a fine head, and the whole plant is in 
admirable form. 
AVe seem to have centred our regard so much upon 
the Christmas Rose that we have almost forgotten the 
existence of the Lenten one. That the love for the 
white one is due to its existing purity of colour and its 
great value as cut flowers there can be no doubt. 
Still, the blooms are very liable to be harmed by rains, 
frosts, or insects, whilst those of the Lenten Rose are 
carried well above the soil and seem to suffer nothing, 
let the weather be ever so severe or unkind. Whenever 
we obtain a pure white-flowered H. colchicus hardy and 
robust, we shall indeed possess a prize. — A. D. 
-- 
ON THE EFFECTS OF URBAN 
FOG- UPON CULTIVATED PLANTS. 
An investigation on the above matter has been under¬ 
taken by the Scientific Committee of the Royal 
Horticultural Society, supported by a grant from the 
Royal Society to meet the cost of apparatus, &c. 
Experiments, observations, and inquiries have been 
and are being conducted by Dr. F. W. Oliver, who 
presented a preliminary report to the Scientific Com¬ 
mittee on the 24th 'ult. The report being rather a 
lengthy one for the space at our command, we have 
made a number of extracts which may prove of interest 
or service to our readers. So far, only plants under 
glass have been taken into consideration. 
I. —Urban Fog and Country Mist. —My own obser¬ 
vations during cold weather in London without fog, and 
the evidence to hand from a distance, as to frost with 
and without mists, point to the fact that, with proper 
precautions, no appreciable damage is done to plants. 
The fog leaves the well-known deposit of filth on glass¬ 
houses and evergreen foliage ; and if such districts 
escape the more serious effects, observable in or near 
the larger smoke-producing areas, it is due to the 
relatively small concentration of the impurities in 
those fogs. 
II. j Extent of the London Fog-area. —The extent of 
the fogs is greatest in a westerly and south-westerly 
direction, and has been traced as far as thirty-five 
miles away westward, and twenty-five miles south¬ 
west, under special atmospheric conditions. Exception¬ 
ally the London fogs are met with at even fifty miles 
distance on this side. With the wind in an easterly 
or north-easterly direction, these outlying districts 
receive visitations of fog with the accompaniments of 
sooty deposits and sulphurous smell. No doubt the 
concentration is not so considerable, nor the duration 
so long as nearer London, but it is sufficient to at once 
affect the buds and flowers of such sensitive Orchids as 
Lfelia anceps, Cattleya Trianse, Calanthe, &c. The 
effect of the fog on foliage at these distances is 
fortunately small, though in certain instances it is 
sufficient to destroy the seedlings of Cucurhitas, Toma- 
tos, &c., which are extremely sensitive. As one follows 
the effects of the fog down the Thames valley, from the 
most outlying stations affected, to London, the observed 
effects increase in severity, till they are indistinguish¬ 
able from those noted at stations actually within the 
metropolis. At Kew, for instance, the destruction has 
been most disheartening, it having come to flowers, 
flower-buds, and foliage alike. Effects of similar nature, 
but less in total magnitude, are reported from spots 
five miles further west. Southwards, the North Downs 
afford a valuable barrier, which in many cases would 
seem to filter off the more deleterious constituents of 
the fog. Indeed, the configuration of the country and 
the nature of the sub-soil have an important influence 
in determining the immunity of a given locality from 
damage. Eastwards I have information as to damage 
from so great a distance as Maidstone, over thirty 
miles. All my correspondents emphasize the non¬ 
hurtful nature of the sea-fogs prevalent in this quarter. 
To the north and north-east the fog-effects do not 
extend.to such extreme distances, and the conditions 
for winter cultivation are consequently more favourable 
for cultivation on that side of the metropolis. 
III. The Fogs of the Winter 1890-91.—It is 
needless to say that the past winter has been one 
singularly favourable for the purposes of an investi¬ 
gation of this character. The season opened with a 
severe fog of short duration during the second week in 
October, which left its traces on vegetation in the 
London area. This was the only serious instance of a 
fog on which observations of hardy plants could he 
made, as the conditions were not complicated by the 
presence of frost. I am indebted to Mr. C. T. Druery for 
an interesting account of its effects, unprecedented in 
his experience, upon his collection of hardy Ferns at 
Forest Gate. Though there were minor fogs during 
November, it was during the long periods before and 
after Christmas, and again in February, that all the 
worst effects were exhibited by vegetation under 
glass. These two spells differed considerably in their 
nature. The Christmas fogs were accompanied by 
exceptionally severe frosts, were on the whole much 
darker overhead, and contained a larger amount of 
noxious matter. In addition to this, the duration of 
daylight was considerably shorter than in February. 
On the other hand, though in February the fogs were 
exceedingly opaque, the general average of light 
reduction was not so great as at Christmas. The vertical 
extent of the fogs in February was such that on many 
occasions the sun was able to partially disperse them 
for a short period at noon. 
Both fogs had a marked effect on flowers, but on the 
whole at Christmas, to instance only one genus of 
plants, Cypripedium, the effects were more marked. 
Cypripedium is perhaps as little affected by fog as any 
genus of Orchids I have met with. \ et, in a large 
collection continuously under my observation, it was 
patent that the damage done was markedly less in 
February than at Christmas. In the collections of 
plants under observation, the damage to foliage was 
also greater during the former ; this both as regards the 
dropping of leaves, which I have reason to believe to 
be greatly brought about by the reduction of light for 
a lengthened period, and also in the formation of actual 
corrosions of portions of the leaf-surface. 
It must be remembered, in estimating the relative 
damage caused by these two fogs, that the earlier one 
destroyed the greater part of the foliage of very many 
soft-wooded plants, so that there was less surface ex¬ 
posed to attack on the second occasion. Nevertheless, 
so favourable were the circumstances during the latter 
part of January and the first week in February, that 
rapid growth had in many cases taken place. If we 
narrow the comparison to the damage (corrosions) sus¬ 
tained by young, and relatively unprotected leaves 
during the two periods, without doubt that at Christmas 
was immeasurably greater than in February. These 
remarks are based on observations of collections con¬ 
tinuously under my eye, and situate in the worst 
districts. Full details are not yet to hand from cor¬ 
respondents at outlying stations, so that it is possible 
I may have to modify these observations when I come 
to take a general survey. Thus at Kew, the ill effects 
noted after the February fogs were quite as bad as at 
Christmas, whilst further east the reverse was the case. 
Other considerations confirm the view that in February 
the fog-nucleus was several miles further west than at 
Christmas. I have in my notes full details of the 
damage obtaining from these fogs from many sources, 
but with these horticulturists are, iu general, only 
too familiar, and they may well be reserved for the 
report on the whole question. 
(To be continued.) 
