work to do in the short dark days of this month. Although there may be
little or nothing to plant or sow, and few flowers need repotting, yet
there are soils to obtain and store for future use; former heaps to
turn over and remake; dead leaves to remove from plants in pits and
houses; stakes and neat sticks to prepare for subjects which will need
support by-and-by; beds and borders to enrich, and many other duties to
perform. In the evenings, too, there are new combinations and fresh
harmonies in colour to be designed for beds and groups in borders; the
requirements for the coming season to consider while experience gained
during the closing year is still fresh in the memory; the position of
plants in pits and frames and houses to forecast, so that the plan of
the summer campaign may be clearly understood, and all the resources of
the garden be under intelligent control. The fluctuations of the
thermometer have also to be watched, and means adopted to save plants
from injury by a sudden fall of temperature. Altogether, there are
abundant sources of profitable employment for those who have a mind to
work.
Bulbs, such as Hyacinths, Tulips, Crocuses, &c., which have not been
planted, will have commenced growing, notwithstanding the precautions
taken to prevent it, thus showing that they ought to be in the ground.
The growth has been made at the expense of the bulb itself, for there
are no fibrous roots from which to draw support. Therefore it can
scarcely be expected that the flowers from very late plantings will be
quite so good as the same bulbs would have produced had they been put
in at an earlier period. Still there are cases when the delay is
unavoidable, and it is reassuring to know that sound bulbs carefully
set at the proper depth will produce flowers only in a degree inferior
to those from earlier plantings.
Bulbs in store, such as Begonia, Dahlia, Gladiolus, and Gloxinia,
should be passed in review. Examination will almost certainly reveal
some unsound specimens, and their removal may save valuable companions
from their contaminating influence. This practice should be followed up
about once a fortnight until all are eventually planted.
THE PESTS OF GARDEN PLANTS
The life-history of plant pests and ground vermin, with the best means
of saving various crops from their ravages, are dealt with in a series
of valuable leaflets issued by the Ministry of Agriculture and
Fisheries. These leaflets embrace a very large number of subjects,
several of which belong to the farm and the orchard and are beyond the
scope of the present volume. Others are rarely met with, but concerning
those which are common to the majority of gardens we offer information
which will, we hope, enable readers to safeguard their crops from
disaster.
When adverse weather operates injuriously on vegetation the plagues
that infest garden plants usually acquire increased power in proportion
to the degree of debility to which vegetation is reduced. This
circumstance perfectly accords with the general law of Nature, and is
full of instruction as to the means of saving plants from serious
injury by vermin. The keen, dry east wind that so often jeopardises
fruit crops is usually followed by visitations of fly and maggot, and
in this case the cause is beyond human power or forethought. But
neglect of watering and air-giving to pot plants can be avoided. Good
cultivation not only insures fine specimens, but is often the means of
preventing the plants from failing under the attacks of Aphis, Mealy
Bug, and other enemies against which the gardener has to fight an
unceasing battle.
Insects are among the frailest of living creatures and they perish at a
touch. As they breathe through the pores of the skin, water alone—the
promoter of life and cleanliness—is death to them; and they are still
more subject to sure destruction when to the water is added an active
poison, such as tobacco, or a substance that adheres to them and stops
the process of breathing, such as glue, clay, sulphur, soft soap, and
the numerous preparations that are specially made to annihilate insect
hosts.
The various stages through which the larger insects pass place them
within our power at some period of their existence. The butterfly may
float beyond the reach of harm, but in the caterpillar or the chrysalis
state it can be dealt with effectually. Again, we may be powerless to
destroy the Chafer grubs as they feed or hibernate beneath turf, but in
their perfect state as Cockchafers or Rose Chafers many may be beaten
down during quiet evenings, and others can be shaken from Roses at dawn
or sunset. A knowledge of the life-history of injurious insects will
suggest what is to be done and the right time for doing it, so that
often by simple treatment they may be destroyed.
The expense of preparing mixtures and washes may be in some degree
lessened by economy of application. A drenching-board fitted on a firm
frame, should be provided in every place where plant-growing is carried
on to any extent. The board should slope from a resting ridge at the
base. The plant in its pot may be laid on the board, with the bottom of
the pot against the resting ridge, and a pail should be put to catch
the liquid used as it drains from the plant after syringing. Every
general washing or fumigating should be followed by another at an
interval of from a week to a fortnight, because, although the first
operation may kill every insect, there will be many living eggs left,
and these renew the race, and very soon bring the plants into as bad a
state as ever, unless consigned to a happy despatch as their parents
were. In some cases it will be more economical to feed than to destroy
the vermin; and, as a rule, feeding vermin does not add to their
numbers, in the same or any future season, for insect life is so
strangely dependent on certain conditions of temperature, &c., that if
the season is not favourable to a particular kind it will be scarce, no
matter how plentiful it may have been in a previous year. In the case
of the Turnip Fly, feeding is frequently the cheapest and surest way of
saving the crop. It is customary with Dahlia-growers, and, indeed, with
the growers of florists’ flowers generally, to sow Lettuces where the
flowers are to be planted, for so long as Lettuces are on the spot
Slugs and Snails will prefer them to other food. As the Lettuces
themselves serve the purpose of traps, the Snails and Slugs congregated
about them may, towards evening, be caught and destroyed.
In using a mixture for the first time, it is advisable to try it on one
plant only, and that, of course, the worst in the collection affected.
If the preparation is too strong, the truth will be declared by the
state of the plant within twenty-four hours; thus a little caution may
prevent a great loss. Another good rule is to employ the several
remedies in a rather weak state until experience has been gained, for
not only has the strength of the medicine to be considered, but the
management of the patient before and after it is administered. It is
above all things important to be thorough in the cleansing of plants,
because they succumb rapidly to the attacks of insects, and should be
effectually and promptly cleaned or consigned to the fire. If left in a
foul state they spread the infection to all around. In the space at our
command it is only possible to notice a few of the garden pests, and we
begin with one of the most frequent and troublesome of plant foes.
Aphis in some form or other is the most persistent and perplexing of
plant pests. The Green Fly is the enemy of the softer kinds of
vegetation, and the Blue and the Black Fly are common plagues of the
Peach-house and the orchard. The tender body of the Aphis is instantly
affected by conditions unfavourable to its life, and it is therefore
easily killed; but its marvellous power of reproduction renders its
extinction impossible, for in every instance a few escape, and very
soon re-establish their race. Two methods for the destruction of Aphis
are in vogue. One is fumigation by tobacco, either pure or in some of
the numerous preparations offered, including several popular
insecticides which have nicotine as a basis. These are both clean and
effective. When a houseful of plants is infested no time should be
lost, and the evening is most suitable for dealing with the pests. The
plants ought to be quite dry and the house closely shut. A dense cloud
of smoke without flame is required. Allow the smoke to do its deadly
work during the night. Early next morning syringe the plants freely,
and in the course of an hour or so give air. The other remedy is to use
one of the many liquids which are inimical to the life of Aphis and
other insect pests. To economise the liquid it is advisable to fill a
pail or tub and immerse the plants individually. Take one in the right
hand and spread the fingers of the left hand over the surface of the
soil to prevent an accident; then turn the plant over and plunge the
foliage in the liquid, moving it up and down briskly two or three
times. If this is not practicable syringe the plants, taking care to
wet the leaves on both sides. On the following day syringe with pure
soft water.
Rose trees may generally be cleansed of fly by means of the garden
engine and pure water only, the essential point being to direct the
water on the trees with some amount of force for several evenings in
succession whenever the fly threatens to obtain the mastery.
Soft soap dissolved in water makes a cheap and effectual wash for
exterminating all kinds of Aphis, and to these ingredients quassia may
with advantage be added. One pound of soft soap will suffice for ten
gallons of water, into which stir the extract obtained by boiling one
pound of quassia chips in water. Pot plants can be dipped in it as
already advised, or the solution may be applied by means of the
syringe. On the following day the plants should be cleansed with pure
soft water.
The Bean Aphis, also known as the Bean Plant Louse, or Black Dolphin
_(Aphis rumicis)_. Our illustration shows the wingless female and pupa
natural size and magnified. The pupa is black with greyish white
mottlings, while the female is deep greenish black in colour. This
insect commonly attacks the young shoots and tops of Broad Beans. It is
well to cut off the infected tops and burn them. Should the attack be
repeated spray the Beans with a solution of soft soap and quassia.
[Illustration: Bean Aphis] BEAN APHIS
_Aphis fabæ_ (pupa and female)
The Pea Siphon-Aphis (_Siphonophora pisi_, Kalt).—Among the aphides
peculiar to vegetables this is one of the most common.
[Illustration: Pea Siphon-Aphis] PEA SIPHON-APHIS
_Siphonophora pisis_
Our illustration shows the natural size and an enlarged figure of the
greenish-winged and green-tinted wingless females, as produced, not
from eggs, but alive and developed. This insect is occasionally very
destructive to Pea crops.
American Blight, or Woolly Aphis, generally appears first on trees
grafted on dwarfing stocks, particularly the bad forms of the Paradise
Apple. Rapidly the mischief spreads, healthy trees become infested, and
unless checked an orchard is speedily ruined. Andrew Murray says that
in bad cases of American Blight it is sometimes necessary to root up
and burn all the trees, and let the ground remain unplanted for a year
or two. Fruit trees should be examined periodically for this pest, and
immediately the woolly spots are detected small tainted boughs should
be pruned away, and from the mainstems and large branches diseased
spots can be pared off. The operation may need a bold and vigorous hand
if the trees are to be saved, and it is important that every scrap
should be burned. There is almost certain to be a further appearance of
the Blight, which should be destroyed by one of the many remedies known
to be effectual. Fir Tree Oil Insecticide has proved to be an excellent
remedy. Gishurst Compound, in the proportion of eight ounces to a
gallon of water, with sufficient clay added to render it adhesive,
makes a capital winter paint for Apple trees. But there is no cheap
remedy equal to soft soap for smothering American Blight in the
crannies of the bark. The soap may be rubbed into the diseased spots,
or as a wash it can be brushed into the boughs.
[Illustration: American Blight] AMERICAN BLIGHT
_Schizoneura lanigera_
Our illustration shows a piece of Apple twig with the aphides and their
woolly material natural size. The enlarged figures represent the winged
female and the wingless larva of the Apple Blight Aphis _(Schizoneura
lanigera_). The insect is deep purplish brown in colour, and the
well-known bluish white cottony material naturally exudes from it.
The Carrot Fly (_Psila rosæ_, Fab.), with its larva, pupa, and perfect
insect, is illustrated natural size and enlarged. The ochreous shining
larvæ live upon the tap-roots of the Carrot, and by eating into them
cause them to rot. In colour the body of the fly is an intensely dark
greenish black, with a rusty ochreous head. The presence of the larvæ
in the root is made known by the change in the colour of the leaves
from green to yellow, and the attacked plants should be promptly forked
out entire and burned.
[Illustration: Carrot Fly] CARROT FLY
_Psila Rosæ_ (with maggot and chrysalis)
It is well to dig the ground in autumn, so that the earth may be
exposed to the frosts of winter and the pupæ to the attention of birds.
After sowing, spray the Carrot bed with paraffin emulsion. Spray again
after germination, and a third time when thinning is finished. The
emulsion to be made by dissolving half a pound of soft soap in a gallon
of boiling water. While still boiling, pour the liquid into two gallons
of paraffin and churn thoroughly until a buttery mass results. This
will keep for a long time in tins. Before use, dilute with twenty times
the quantity of water—soft water if possible. This is an excellent
preventive. After the work of thinning, the fly may also be kept off
the plants by scattering over them ashes, sand, or earth, impregnated
with paraffin. Carbolic powder and soot are both disagreeable to the
insect. It has been observed that when singling the disturbance of the
soil is favourable to the operations of the Carrot Fly. A copious
watering when the task is ended will firm the earth round the remaining
roots, and prevent the fly from easily getting down to deposit eggs.
Carrots and Parsnips are often attacked by the larva of a Carrot Moth
(_Depressaria cicutella_), which spins webs for security while feeding,
and sometimes works havoc among the foliage. A simple remedy is to
shake the caterpillars from the leaves of the plants, when they can be
destroyed by the use of lime.
Celery Fly.—The apparent blisters in Celery leaves are spots deficient
of leaf-green, which the larva of the Celery Fly has eaten. Dusting
newly-planted Celery with lime or soot may do something to prevent the
fly from laying its eggs, but the most certain preventive is to boil
half a pound of coal tar in one gallon of water for twenty minutes, add
fifty gallons of clear water, and syringe the plants about noon once or
twice from the middle to the end of June. When once the grub has made a
home, it should be crushed by pinching the leaf between the finger and
thumb, or the injured portions of the leaves should be cut out and
burned. In doing this it must always be remembered that the leaves are
as much needed by the plant as the roots, and every leaf removed tends
to diminish the vigour of the plant. Our illustration shows the Celery
Fly (formerly known as _Tephritis onopordinis_, but now called _Acidia
heraclei_) natural size and magnified. This fly is also destructive to
the leaves of Parsnips, and is named _onopordinis_ from its habit of
frequenting the Cotton Thistle (_Onopordon Acanthium_). The larva is
white to very pale green, the fly is shining tawny. An Ichneumon Fly
detects the larva of the Celery Fly in the Celery and Parsnip leaves,
and lays its eggs in the body of the larva. These parasites, named
_Alysia apii_, assist in reducing the numbers of the Celery Fly.
[Illustration: Celery Fly] CELERY FLY AND LARVA
_Tephritis onopordinis_
All Celery refuse should be destroyed by fire. Infested ground may, if
suitable, be trenched, bringing the subsoil to the surface and burying
the top soil containing the pupæ. Frequent rough digging and the
exposure of fresh surfaces to be searched by birds will also do
something to abate the number of this pest. But in bad cases it will be
necessary to resort to gas-lime, which poisons the pupæ and eventually
benefits the soil, although in the season immediately following its use
crops may be less satisfactory than usual.
Onion Fly.—Onions are frequently attacked by the larvæ of the Onion
Fly, and in some instances the entire crop is destroyed. Our
illustration shows the natural size of the fly and maggot, with
magnified representations of both. The fly lays six to eight eggs on an
Onion plant, generally just above the ground. These eggs hatch in from
five to seven days, according to the temperature, and the maggots at
once burrow into the Onion. The result is soon visible in the
discoloration of the leaves which turn yellow and begin to decay.
Several generations of the insect, the scientific name of which is
_Phorbia cepetorum_, appear in the course of a single season. A close
ally is the Cabbage Root Fly (_P. brassicæ_), the destroyer of Cabbage
roots.
[Illustration: Onion Fly] ONION FLY AND LARVA
_Anthomyia ceparum_
Among the numerous methods of preventing attack and of destroying the
grubs the following are worth attention:—
Where this pest proves very troublesome it may be desirable to transfer
Onion growing to new ground until the infested land has been purged of
the pupæ. Instead of throwing useless Onion material on the waste heap
to afford the fly a home for its eggs, every scrap should be burned. As
the preparation of an Onion bed approaches completion, powdered lime
well mixed with soot, in the proportion of two bushels of the former to
one of the latter, may be sown evenly over the surface and raked in.
Sand impregnated with paraffin sown along the drills has answered as a
preventive. Vaporite is a destroyer of the pupæ; this preparation has
proved deadly to ground vermin generally. Earthing up the Onions was
proved by Miss Ormerod’s experiment to be effective. The objection to
this procedure is the probability of enlarged necks which are not
wanted. An emulsion, composed of one pint of paraffin, one pound of
soft soap mixed with ten gallons of water, thoroughly churned by a hand
syringe and sprayed over the young plants in a fine mist, is a valuable
preventive. The dose may be repeated after rainfall, if necessary. The
quantities named suffice for a small plot only. Soapsuds are
destructive to the maggots, disagreeable to the fly, and beneficial to
the young plants. The suds should be sprayed over the bed from a
watering can on the first appearance of a yellow colour in the grass.
As a final suggestion reference may be made to a singular fact which we
do not profess to explain, viz. that transplanted Onions are very
seldom touched by grub. The modern practice of raising seedlings under
glass in January or February, and planting out in open beds in April,
offers the advantage of a long season of growth combined with
comparative immunity from attack by the Onion Fly.
Turnip Fly, or Flea, is well known to the gardener, and is the most
troublesome of all the aërial pests of the farm, and one with which it
is most difficult to cope, not only because of its general diffusion
and numbers, but because it produces a succession of broods throughout
the summer, and is therefore always in force, ready to devour the crop
immediately it appears. The so-called ‘Fly’ is a small beetle named
_Haltica (Phyllotreta) nemorum_, strongly made, and decidedly
voracious. The larvæ are not to be feared, except that, of course, they
in due time become beetles. In the perfect state this winged jumping
insect makes havoc of the rising plant of Turnips, but the crop is only
in danger while in the seed-leaf stage. It is in the spring and early
summer chiefly that the ravages of these insects occasion perplexity,
for they awaken from their winter torpor active and hungry, and have a
ready appetite for almost any cruciferous plant. Hence we see the
leaves of Radishes pierced by them, and all such weeds as Charlock,
Cuckoo Flower, Hedge Garlic, and Water Cress serve them for food until
the Turnip crops are on the move, when they will travel miles, even
against the wind, to wreck the farmer’s hopes. The Cabbage Flea
(_Haltica oleracea_) in some districts is equally troublesome, if not
more so. Whole Cabbages may be destroyed by this pest, and even Hops
are often ruined by it.
[Illustration: Turnip Fly] TURNIP FLY OR BEETLE
_Haltica nemorum_ (with larva and chrysalis)
Preventive and remedial measures that can easily be carried out in a
garden may be impracticable on a farm. We propose to enumerate them
briefly as they occur to us, leaving the ultimate choice of weapons to
those who may unfortunately find occasion to use them.
One precaution is to insure a quick germination of the seed and strong
growth of the plant in its seed-leaf stage. The cotyledons are tender
and tasty, perhaps sugary from Nature’s process of malting; and while
the seed-leaf is assailable the _Haltica_ makes the best of the shining
hour. The seed sown should be all of one age, and the newest possible,
because of the need for a quick and strong growth. When a powerful
artificial is sown with the seed, the quantity of seed must be
increased, as a proportion may be killed by the manure. It is important
always to drill Turnip seed; broadcasting seems to invite the Fly—at
all events, a drilled crop is generally safer. Before sowing, the seed
may be soaked in paraffin or turpentine. Of the two the latter appears
to be the more successful in keeping the insects at bay.
Rolling an infested plant disturbs and weakens the insects and
stimulates the young plant.
The sprinkling of slaked lime over the seedlings is at once a safe and
an efficient process, and possesses the additional advantage of being
beneficial to the plant. We are aware that it does not always succeed,
but we are inclined to attribute the failure to a bad quality of the
lime, or a careless method of employing it. There should be enough put
on to make the plants white, and they will be none the worse for the
whitening. Dustings of fine ashes or soot are scarcely less effective,
but salt must not be used, for it injures the plants and does not hurt
the beetle. All such dustings should be done in the early morning,
while the plants are wet with dew. To apply a dusting at midday, when
the sun shines gaily, is to waste time, and probably many of the
recorded failures might be explained if we knew at what hour and in
what sort of weather the work was done. Nets and sticking boards have
been tried and found effectual, and yet such things are rarely used. A
board thickly covered with white paint, drawn over the plot on a still,
sunny day, soon becomes a black board by the myriads of _Halticas_ that
jump at and remain attached to it, the victims of their extravagant
love of light. Old sacks soaked in paraffin and drawn over the drills
impart a disagreeable flavour to the leaves, and a very fine spray of
paraffin distributed by a machine specially constructed for the purpose
has proved effective.
Finally, this, in common with all other insects in the winged state,
needs a dry air and some degree of warmth for its health and happiness.
Many kinds of larvæ need moisture, but no winged insect can abide
moisture long, and herein is a clue to the eradication of Turnip Fly.
By the simple process of spraying the plant three or four times a day,
until it is out of the seed-leaf, and the danger is over, it is
possible in the garden to wash out the _Haltica_; and any kind of
insecticide or flavouring, such as quassia, may be mingled with the
water to render the plants distasteful to the insects.