SOWING SEEDS--PLANTING BULBS AND TUBERS--TRANSPLANTING AND WATERING.
_Sowing Seeds._--The principal points to be attended to in sowing seeds
are, first, to prepare the ground so that the young and tender roots
thrown out by the seeds may easily penetrate into it; secondly, to fix
the seeds firmly in the soil; thirdly, to cover them, so as to exclude
the light, which impedes vegetation, and to preserve a sufficiency of
moisture round them to encourage it; and, fourthly, not to bury them
so deeply as either to deprive them of the beneficial influence of
the air, or to throw any unnecessary impediments in the way of their
ascending shoots.
The preparation of the soil has been already described in the chapter
on digging, and the reasons why it is necessary have been there given;
but why seeds should be firmly embedded in it, seems to require
explanation. It is well known that gardeners, before they either
sow a bed in the kitchen-garden, or a patch of flower-seeds in the
flower-garden, generally “firm the ground,” as they call it, by beating
it well with the back of the spade, or pressing it with the saucer of a
flower-pot; and there can be no doubt that this is done in order that
the seeds may be firmly imbedded in the soil. When lawns are sown with
grass-seeds also, the seeds are frequently rolled in, evidently for the
same purpose. The only question, therefore, is, why is this necessary;
and the answer appears to be, that a degree of permanence and stability
is essential to enable nature to accommodate the plant to the situation
in which it is placed. When there is this degree of permanence and
stability, it is astonishing to observe the efforts that plants will
make to provide for their wants; but without it, seeds will not even
vegetate. Thus we often see large trees springing from crevices in
apparently bare rocks; while not even a blade of grass will grow among
the moving sands of a desert.
The reasons for the second and third points of covering the seeds, and
yet not covering them too deeply, appear more obvious; and yet they
also require a little explanation. The seeds are covered to keep them
in darkness, and to retain round them a proper quantity of moisture;
not only to make them swell and begin to vegetate, but to enable the
roots to perform their proper functions; since, if exposed to the air,
they would become dry and withered, and lose the power of contracting
and dilating, which is essential to enable them to imbibe and digest
their food. Burying the seeds too deeply is obviously injurious in
impeding the progress of the young shoot to the light; and in placing
it in an unnatural position. When a seed vegetates too far below the
surface, a part of the stem of the plant must be buried; and this
part not being intended to remain under-ground, is not protected from
the dangers it is likely to meet with there. It is thus peculiarly
liable to be assailed by slugs and all kinds of insects, and to
become rotten by damp, or withered by heat. It is also very possible
to bury a seed so deeply as to prevent it from vegetating at all. The
ground has more of both warmth and moisture near the surface than at
a great depth, as it is warmed by the rays of the sun, and moistened
by the rain; but besides this, seeds will not vegetate, even when
they are amply supplied with heat and moisture, if they are excluded
from the influence of the air. Every ripe seed in a dry state is a
concentration of carbon, which, when dissolved by moisture, and its
particles set in motion by heat, is in a fit state to combine with the
oxygen in the atmosphere, and thus to form the carbonic acid gas which
is the nourishment of the expanding plant. For this reason, seeds, and
newly sprung-up plants do not want to be supplied with manure, and
air is much more essential to them: they have enough carbon in their
cotyledons or seed-leaves, and they only want oxygen to combine with
it, to enable them to develope their other leaves; and this is the
reason why young plants, raised on a hotbed, are always given air, or
they become yellow and withered. Light absorbs the oxygen from plants,
and occasions a deposition of the carbon. Thus seeds and seedlings do
not require much light; it is indeed injurious to them, as it undoes
in some degree what the air has been doing for them: but young plants,
when they have expanded two or three pairs of leaves, and when the
stock of carbon contained in their cotyledons, or seed-leaves, is
exhausted, require light to enable them to elaborate their sap, without
which the process of vegetation could not go on. Abundance of light
also is favourable to the development of flowers, and the ripening
of seeds; as it aids the concentration of carbon, which they require
to make them fertile. The curious fact that seeds, though abundantly
supplied with warmth and moisture, will not vegetate without the
assistance of the air, was lately verified in Italy; where the Po,
having overflowed its banks near Mantua, deposited a great quantity of
mud on some meadows; and from this mud sprang up a plentiful crop of
black poplars, no doubt from seeds that had fallen into the river from
a row of trees of that kind, which had formerly grown on its banks,
but which had been cut down many years previously. Another instance
occurred in the case of some raspberry seeds found in the body of an
ancient Briton discovered in a tumulus in Dorsetshire. Some of these
seeds were sown in the London Horticultural Society’s Garden at Turnham
Green, where they vegetated, and the plants produced from them are
still (1839) growing. Numerous other nearly similar instances, will
be found in _Jesse’s Gleanings_, _Hooker’s Botanical Miscellany_, and
numerous other works. Steeping seeds in oxalic acid, &c. to make them
vegetate, is efficacious; as there is a speedier combination between
the carbon in the seeds, and the oxygen in the acid, than can be
effected by the ordinary agency of the air in parting with its oxygen
to them.
_Planting bulbs and tubers_ bears considerable analogy to sowing seeds.
The bulb or tuber may indeed be considered as only a seed of larger
growth, since it requires the combined influence of air, warmth, and
moisture to make it vegetate, and then it throws out a stem, leaves,
and roots like a seed. There is, however, one important difference
between them; the seed expends its accumulated stock of carbon in
giving birth to the root, stem, and leaves, after which it withers away
and disappears; while the bulb or tuber continues to exist during the
whole life of the plant, and appears to contain a reservoir of carbon,
which it only parts with slowly, and as circumstances may require.
Though bulbs and tubers have here been mentioned as almost synonymous,
modern botanists make several distinctions between them. The tunicated
bulbs, such as those of the hyacinth and the onion, and the squamose
bulbs, such as those of the lily, they consider to be underground buds;
while tubers such as those of the dahlia, and the potatoe, and solid
bulbs or corms, such as those of the crocus, they regard as underground
stems.
These distinctions, however, though they may be interesting to the
botanist and vegetable physiologist, are of little or no use in
practice; the practical gardener treating bulbs and tubers exactly
alike, and planting them as he would sow a seed: that is to say, he
fixes them firmly in the ground, and covers them, but not so deeply as
to exclude the air. In preparing a bed for hyacinths or other tunicated
bulbs, it is necessary to pulverize the soil to a much greater depth
than for ordinary seeds; as the fibrous roots of the hyacinth descend
perpendicularly to a considerable depth, as may be seen when these
plants are grown in glasses. The very circumstance of growing hyacinths
in glasses, where they vegetate and send down their roots exposed to
the full influence of the light, appears contrary to the usual effects
of light on vegetation; and indeed the plants are said generally to
thrive best, when the glasses are kept in the dark till the roots are
half grown. However this may be, it is quite certain that hyacinths
in glasses should never be kept in darkness when their leaves begin
to expand; as, if there be not abundance of light to occasion rapid
evaporation from the leaves, the plants will soon become surcharged
with moisture from the quantity constantly supplied to their roots; and
the leaves will turn yellow, and look flaccid, and unhealthy, while the
flowers will be stunted, or will fall off without expanding.
_Transplanting._--The points to be attended to in transplanting,
are--care in taking up, to avoid injuring the spongioles of the roots;
planting firmly to enable the plant to take a secure hold of the soil;
shading to prevent the evaporation from the leaves from being greater
than the plant in its enfeebled state can support; and watering that it
may be abundantly supplied with food in its new abode. The first point
is to avoid injuring the roots, and it is only necessary to consider
the construction and uses of these most important organs to perceive
how impossible it is for the plant to thrive, unless they are in a
perfectly healthy state. Roots generally consist of two parts; the main
roots which are intended to act as grappling irons to enable the plants
to take a firm hold of the ground, and the fibrous roots which are
intended to supply the plant with nourishment. These fibrous roots are
most liable to receive injury from transplanting, as they are covered
with a very fine cellular integument, so delicate in its texture as to
be very easily bruised; and they each terminate in a number of small
pores of extraordinary delicacy and susceptibility, which act as little
sponges to imbibe moisture for the use of the plant. It is well known
that these spongioles are the only means which the plant possesses of
imbibing food, and that if they should be all cut off, the plant must
provide itself with others, or perish for want of nourishment. These
spongioles are exactly of the nature of a sponge; they expand at the
approach of moisture, and when surcharged with it, they contract, and
thus force it into the fibrous roots, the cellular integument of which
dilates to receive it; hence the moisture is forced, by capillary
attraction, as it is supposed, into the main roots, and thence into the
stem and branches of the plant; circulating like the blood, and after
it has been elaborated in the leaves, as the blood is in the lungs,
dispensing nourishment to every part as it goes along.
The roots have no pores but those forming the spongioles; and only the
fibrous roots appear to possess the power of alternate dilation and
contraction, which power evidently depends on their cellular tissue
being in an entire and healthy state. Thus, it is quite evident that
if the spongiole of any fibril be crushed, or even the cellular tissue
injured, it can no longer act as a mouth and throat to convey food to
the plant. When this is the case, the injured part should be instantly
removed; as its elasticity can never be restored, and it is much
better for the plant to be forced to throw out a new fibril, than to
be obliged to carry on its circulation weakly and imperfectly with a
diseased one. Whenever a plant is taken up for transplanting, its roots
should therefore be carefully examined, and all their injured parts
cut off, before it is replaced in the ground. Deciduous plants, and
particularly trees and shrubs, are generally transplanted when they are
without their leaves; because at that season they are in no danger of
suffering from the effects of evaporation.
_Shading_ is necessary after transplanting all plants that retain their
leaves; as the evaporation from the leaves, if exposed to the full
action of the light, would be greater than the plant could support with
a diminished number of spongioles. If it were possible to transplant
without injuring the fibrils, and if the plant were immediately
supplied with plenty of water, shading would not be required; and,
indeed, when plants are turned out of a pot into the open garden
without breaking the ball of earth round their roots, they are never
shaded. The reason for this is, that as long as a plant remains where
it was first sown, and under favourable circumstances, the evaporation
from its leaves is exactly adapted to its powers of absorbing moisture;
it is therefore evident, that if, by any chance, the number of its
mouths be diminished, the evaporation from its leaves should be checked
also, till the means of supplying a more abundant evaporation are
restored.
_The use of watering_ a transplanted plant, is as obvious as that of
shading. It is simply to supply the spongioles with an abundance of
food, that the increased quantity imbibed by each, may, in some degree,
supply their diminished number.
_All plants will not bear transplanting_, and those that have
tap-roots, such as the carrot, are peculiarly unfitted for it. When
plants having tap-roots are transplanted, it should be into very light
soil, and what is called a puddle should be made to receive them. To
do this, a hole or pit should be formed, deeper than the root of the
plant, and into this pit water should be poured and earth thrown in and
stirred so as to half-fill it with mud. The tap-rooted plant should
then be plunged into the mud, shaking it a little so as to let the mud
penetrate among its fibrous roots, and the hole should be filled in
with light soil. The plant must afterwards be shaded longer than is
usual with other plants; and when water is given, it should be poured
down nearer to the main root than in other cases, as the lateral
fibrous roots never spread far from it. Plants with spreading roots,
when transplanted, should have the pit intended to receive them made
shallow, but very wide in its diameter; so that the roots may be spread
out in it to their fullest extent, except those that appear at all
bruised or injured, which, as before directed, should be cut off with a
sharp knife.
_It is a general rule, in transplanting, never to bury the collar
of a plant_; though this rule has some exceptions in the case of
annuals. Some of these, such as balsams, send out roots from the stem
above the collar; and these plants are always very much improved
by transplanting. Others, the fibrous roots of which are long and
descending, such as hyacinths, bear transplanting very ill, and when
it is absolutely necessary to remove them, it should be done with
an instrument called a transplanter; which may be purchased in any
ironmonger’s shop, and the use of which is to take up a sufficient
quantity of earth with the plant to remove it without disturbing the
roots.
_The uses of transplanting_ are various. When seeds are sown, and
the young plants from them begin to make their appearance, they
will generally be found to be much too thick; and they will require
thinning, either by drawing some of them out and throwing them away,
or by removing them to another bed by transplanting. This, in the case
of annuals, is called by the gardeners pricking out. The young plants
are taken up with a small trowel, and replaced in a hole made for
them, and the earth pressed round them, with the same trowel; the only
care necessary being to make them firm at the root, and yet to avoid
injuring the tender spongioles. Gardeners do this with a dibber, which
they hold in the right hand, and after putting in the young plant with
the left hand, they press the earth round it with the dibber in a
manner that I never could manage to imitate. I have found the trowel,
however, do equally well, though it takes up rather more time.
Another use of transplanting is to remove trees and shrubs from the
nursery to where they are permanently to remain. To enable this to be
done with safety, the trees and shrubs in commercial nurseries are
prepared by being always removed every year, or every other year,
whether they are sold or not. The effect of these frequent removals is
to keep the roots short, and yet provided with numerous spongioles;
for as they are always pruned on every removal, and as the effect of
pruning is to induce the roots pruned to send out two short fibrous
roots armed with spongioles, in the place of every one cut off,
the roots, though confined to a small space, become abundant. The
reverse of this is the case, when plants are left in a natural state.
It has been found, from experience, that plants imbibe more food
than they absolutely require as nourishment from the soil, and that
they eject part of it; also that their roots will not reimbibe this
excrementitious matter, but are continually in search of fresh soil. To
provide for this the fibrous roots are possessed of an extraordinary
power of elongating themselves at their extremities; and thus the roots
of even a small plant, left to nature, will be found to extend to a
great distance on every side. It is obvious that this elongation of the
roots must greatly increase the difficulties attending transplanting.
Where the roots extend to a distance from the tree, a greater extent
of ground has to be disturbed, both to take up the plant, and to
make a pit for replanting it; the risk of injuring the fibrous roots
is increased; and, as nearly all the spongioles will require to be
cut off, from the great length of the roots, and consequent greater
difficulty which will attend taking them up entire, the plant will
be nearly famished before new spongioles can be formed to supply it
with food. All these dangers are avoided by the nursery system of
transplanting; while the inconvenience of confining the roots to so
small a space is obviated, by placing the plant, every time it is
transplanted, in fresh soil.
It is customary, when trees or shrubs are transplanted to the places
where they are permanently to remain, either to make a puddle for them,
or to fix them, as it is called, with water; the object, in both cases,
being to supply the plant with abundance of food in its new situation.
Care is taken, also, to make the roots firm in the soil, and to let
the earth penetrate through all their interstices. To attain these
ends, one gardener generally holds the tree and gently shakes it, while
another is shovelling in the earth among its roots; but this mode has
the disadvantage of sometimes occasioning the roots to become matted.
When the tree is to be fixed with water, after a little earth has been
shovelled in over the roots, water is applied by pouring it from a
watering-pot, held as high as a man can raise it; the watering-pot
used being large, and with a wide spout, the rose of which must be
taken off. More earth is then shovelled in, and water applied again.
This mode of planting has the great advantage of rendering the tree
firm, without staking or treading the earth down round it, as is
usually done. Other gardeners spread the roots out carefully at the
bottom of the hole or pit made to receive them, and then fill in the
earth. In all cases, the ground is either made firm with water, or
trodden down or beaten flat with the spade after planting, so as to
fix the roots firmly in the soil, for the same reasons as nearly a
similar plan is adopted in sowing seeds. Newly transplanted trees are
frequently staked, but this is not essential if the roots are made
firm, and indeed the tree is generally found to do best when the head
is left at liberty to be gently agitated by the wind.
It is a great point, in all cases of transplanting, to preserve the
epidermis or cellular integument of the fibrous roots and spongioles
in a flexible state; and for this reason, the greatest care is taken
to keep them moist. This is the end in view in puddling or fixing by
water in transplanting; and many planters always dip the roots of trees
and shrubs in water before replanting. When a tree or shrub is taken up
that is to be conveyed any distance, the roots should be wrapped up as
soon as it is taken out of the ground, in wet moss, and covered with
bast matting; and where moss cannot be procured, they should be dipped
in very wet mud, and then matted up. Cabbage-plants are frequently
preserved in this manner; and are conveyed, without any other covering
to their roots than a cake of mud, to a considerable distance. In all
cases where plants are taken up long before they are replanted, their
roots should be kept moist by opening a trench, and laying the plants
along it, and then covering their roots with earth. This, gardeners
call, laying plants in by the heels. Where this cannot be done, and the
plants are kept long out of the ground, their roots should be examined,
and moistened from time to time; and before replanting they should be
laid in water for some hours, and afterwards carefully examined, and
the withered and decayed parts cut off.
_In removing large trees_, care is taken to prepare the roots by
cutting a trench round the tree for a year or two before removal, and
pruning off all the roots that project into it. This is to answer the
same purpose as transplanting young trees in a nursery; while the bad
effects of contracting the range of the roots is counteracted, by
filling the trench with rich fresh earth. The removal is also conducted
with much care; and either a large ball of earth is removed with the
tree, or the roots are kept moist, and spread out carefully, at full
length, when the tree is replanted. Some planters, before removing
trees, mark which side stood to the south, in order to replant them
with the same side turned towards the sun; and this is sometimes done
with young trees from a nursery. The reason is, that the tree having
generally largest branches, and being always most flourishing on the
side exposed to the sun; it is thought that its vegetation might be
checked, were a different side presented to that luminary, by the
efforts it must make to accommodate itself to its new situation. On
the other hand, however, it may be urged that changing the position
of the plant, particularly while it is young, will be beneficial in
preventing it from taking any particular bent, and in promoting the
equal distribution of sap through all the branches.
_Watering_ is a most essential branch of culture. It has been already
fully explained that the seed cannot vegetate, and the plant cannot
grow without water. Carbon, and all the other substances that form the
food of plants, must be dissolved in water to enable the spongioles to
take them up; and the spongioles themselves, unless they be kept moist,
will soon lose their power of absorption. Nothing indeed can be more
evident, even to a common observer, than the necessity that plants feel
for water; if a mimulus or a pelargonium in a pot, for example, hang
its head and droop its leaves, what an extraordinary and rapid effect
is produced by giving it water! In an almost incredibly short time its
leaves become firm, and its stem erect; and the plant is not only
preserved from death, but restored to full health and beauty.
Watering appears an extremely simple operation, yet nevertheless
there are several points relating to it that it is necessary to
attend to. One of these is, never to saturate the soil. Water, to be
in the best state for being taken up by the plants, should be kept
in detached globules by the admixture of air; and it should be only
slightly impregnated with nourishing matter from decaying animal or
vegetable substances: for, as already observed, when fully saturated
with nourishment, it becomes unfit for the food of plants. Nothing
can be more admirably and wonderfully adapted for supplying plants
properly with water than rain. In falling through the atmosphere, it is
thoroughly mixed with the air; and in sinking into the soil it becomes
slightly impregnated with nutritious qualities, which it is thus
enabled to convey, in the most beneficial manner, to the plants.
It is a very common mistake, in watering, to pour the water down close
to the stem of the plant. This is injurious in every respect. Water,
when poured profusely on the collar of the plant, which is the point of
junction between the root and the stem, is likely to rot, or otherwise
seriously injure that vital part; while the spongioles, which alone can
absorb the water, so as to benefit the plant, being at the extremity
of the roots, are always as far removed from the stem as the nature
of the plant will allow. Thus, the distance from the stem at which
water should be given varies in different plants. In those that have
tap-roots, such as the carrot, and many other culinary vegetables, the
lateral fibrous roots are short, and the spongioles are comparatively
near the stem; but in trees, and most plants having spreading roots,
the spongioles are generally as far distant from the stem as the
extremity of the branches; and the water, to be efficacious, should be
given there.
_The quantity of water to be given_ varies, not only according to the
nature of the plant, but to the state of its growth. In spring, when
the sap first begins to be in motion, and the young plant is every day
unfolding fresh leaves or blossoms, it requires abundance of water; as
it does when in flower, or when the fruit is swelling. In autumn, on
the contrary, when the fruit is ripening, and in winter, when the plant
is in a state of perfect rest, very little water is necessary, and much
is positively injurious, as being likely either to excite a morbid and
unnatural action in the vessels, or even to bring on rottenness and
decay. Water is necessary for seeds to induce them to germinate; but
much of it is very injurious to young plants when they first come up,
as it unsettles their roots, and almost washes them away. The roots,
also, are at first too weak to imbibe water; and the plants feed on
the nourishment contained in the cotyledons of the seeds. It is when
the second pair of leaves has opened that water is required, though
it should at first be given sparingly. When the plant begins to grow
vigorously, it requires more food; and if it be then kept too short of
nourishment, it becomes stunted in its growth. The quantity of water
requisite also depends on the kind of leaves that the plant unfolds.
A plant with large broad leaves, like the tobacco, requires twice as
much water as a plant with small pinnate leaves, like an acacia. Plants
exposed to a strong light, also, require more than plants grown in the
shade.
_The time for watering plants_ varies according to the season. In
spring and autumn it is best to water plants in the morning. But in
summer, the usual time is the evening; while in winter, the very little
that is required, should be given in the middle of the day. Many
persons object to watering their plants when the sun is upon them; but
this is not at all injurious, so long as the water is not too cold,
and is only given to the roots. Watering the leaves when the sun is
upon them will make them blister, and become covered with pale brown
spots wherever the water has fallen. It is much better to water plants
during sunshine, than to suffer them to become too dry; as when the
spongioles are once withered, no art can restore them. When plants
have been suffered to become too dry, the ground should be loosened
before watering it; and water should be given a little at a time, and
frequently, till the plant appears to have recovered its vigour. A
great deal of the good produced by watering depends on the state of the
ground; as when the ground is hard and compact, it is very possible to
throw a great quantity of water upon it without doing any service to
the plants.
_The kind of water_ used should also be considered. The best is
pond-water, as it is always mixed with air, and is, moreover, generally
impregnated with decayed animal and vegetable matter; and the worst is
clear spring-water, as it is always cold, and is seldom impregnated
with air, or with anything but some mineral substance, which, so far
from doing good, is positively injurious to the plants. Rain-water
collected in open cisterns, and river-water, are both very suitable;
and when only spring-water can be obtained, it should be exposed
for some time to the air before using it. It is always advisable to
have the water at least as warm as the plants to be watered; and for
this reason the water to be used in hot-houses and green-houses,
is generally kept in an open vessel in the house some hours before
using. Watering with warm water is very efficacious in forwarding the
flowering of plants. This was one of the things that was most repugnant
to my prejudices in the course of my instruction in the art of
gardening; and when Mr. Loudon had some nearly boiling hot-water poured
on some boxes of hyacinths that I was very anxious to have brought
forward, I could scarcely refrain from crying out when I saw the steam
rising up from the earth. The hyacinths, however, so far from being
injured, flowered splendidly; though such is the force of prejudice,
that I could never see the little tin vessel containing the heated
water carried out to them without a shudder. The effect of hot-water,
not heated to above 200°, in forwarding bulbs is astonishing; but it
must be observed that it should never be poured on the bulbs, or on the
leaves, but on the earth near the rim of the pot. Hot water is also
very efficacious in softening seeds with hard coverings when soaked in
it; and some of the seeds of the New Holland acacias will not vegetate
in this country till they have been actually boiled.