« 上一頁繼續 »
in a pointed and philosophical manner, endeavoured to draw attention to the subject. However, we want data to proceed upon; the vegetation year, or active period, is not confined by Nature to any given months, but moves by periodical fits. Those fits (a clumsy term, I confess,) are dependent chiefly on the relation that the bottom heat bears to that of the atmosphere.
I am of opinion that the average bottom heat of certain periods is much more in advance of the average of the atmosphere, at the same period, than is commonly imagined. I know it is common to say that the average bottom heat of the year is about 2 or 3 degrees in advance of the average atmospheric temperature ; but this, if correct, proves nothing, except that bottom heat is one of Nature's established principles.
To obtain the data requisite, the year should be divided into natural periods : one of these is obviously the rest period; a second points itself out as the excitable period; and a third as the perfecting or accumulating period. Now, it is not proper, I conceive, to plunge a thermometer 1 or 2 feet deep to ascertain how vegetation is influenced by bottom heat, seeing that the chief and most efficient volume of roots lies probably within from 6 in. to 9 in. of the surface. The radiation, too, from the surface may also be taken into consideration ; as the accumulation of heat by the end of August must be very considerable, especially within 3 in. of the surface.
The time was when bottom heat was only deemed essential for pines and cucumbers; but now few processes of any importance are conducted under glass without it.
Many complain that they cannot get their greenhouse and conservatory as gay through the months of December, January, and February, as they could wish ; and I do not wonder at it. If plants in a somewhat dormant state are to be subjected to a higher temperature all of a sudden, without activity of root, what can be expected but abortions ?
I am led to make these remarks in consequence of observing the effect of bottom heat in flower-forcing in general, more especially Dutch bulbs. Mine have been unusually early and good ; and I adopt a practice which deserves to be more generally known. My hyacinths, narcissuses, &c., are potted at the usual time and in the usual way, and immediately plunged over head in old tan. This so far is every body's plan ; but about the end of October I take them up, and prepare a bottom heat of from 75° to 80° of dung and leaves, between the bricked asparagus pits, and place the pots thereon, covering them as before with old tan. When this heat declines, I prepare the next pit in like way, and remove them into it; keeping them, in fact, in a similar bottom heat constantly. By these means I get my root in advance of the bud ; for, this season, having paid close attention to their movements, I found the pots were full of roots, and well coiled round the bottoms of the pots, before the buds were an inch long. This I conceive to be a point of high importance for on removing them from the asparagus pits to a forcing-pit of 'dung and leaves, where the bottom heat was 80°, and the top heat averaging 65°, the buds came up like magic, and were in bloom in a surprisingly short period.
The same principle applies to nearly all of what are termed forcing flowers ; not excepting strawberries, which, in my opinion, would be much benefited by such a process. However, I have not yet proved this with strawberries, although I have several experiments in progress, bearing on the subject of bottom heat, which I shall probably make known as soon as completed.
When the various flowers possessing capabilities for forcing are taken into consideration, we may fairly conclude that our conservatories and greenhouses ought to be as gay in the month of January as during any part of summer, and so, in fact, have mine been; for I have had abundance of camellias constantly from the first of November (some thousands of blossoms), violets, lilies, azaleas, bulbs, justicias, lilacs, eranthemums, and scarlet geraniums, in great profusion, now, indeed, a complete blaze of colour.
Oulton Park, near Tarporley, Jan. 20. 1843.
ART. V. On pulverising Soil. By John Wichroy. Thougn it is certain that nothing is created without some specific purpose, a inan may be tempted to ask, What can be the use of weeds, seeing that they encumber the ground, and choke up the crops ? The labourer, more industrious than learned, may imagine that weeds are sent to afford him employment in rooting them out ; and he may not be altogether wrong, though he does not carry his view far enough. The advantage does not end here; for, in the act of hoeing the weeds, the soil is pulverised, and thereby encouragement given to the growth of the crops. But for the necessity of hoeing up weeds, this important process of stirring and breaking up the soil would be, it is to be feared, much neglected. However, since the days of Tull, the benefit of pulverising the soil is better understood ; and, though many plans of that great agriculturist were ridiculed in his day, they are now in common use. He tells us that it is of more consequence to stir the soil than to manure it, in short, that if the former be practised, manure will not be wanted; and that hoeing ought to be done at all times, instead of weeding. It is useless for me to comment on the first; and hoeing is not at all times practicable. Weeds will not die in wet weather ; and it is injurious to tread upon the land at that time. Hoeing, moreover, is hurtful to some crops in very dry weather, from letting too much moisture escape, notwithstanding the opinion of Tull. A proof of this is the fact that the best onions often grow on the hard paths between the beds. The reason is obvious ; the firm soil retains moisture longer than that which is loose. This circumstance led to the practice of treading down onion-beds fresh sown, as also of pressing down dry earth in which fine seeds are sown.
Í have said enough above to obviate the supposition that I am opposed to hoeing or stirring the soil. Mr. Barnes, too, has noticed its great utility in the November Number of this Magazine, for which its readers are much indebted to him. He justly observes that gardeners have many kinds of blights to contend against, without the injury caused by handling the fruit, as servants are too much in the habit of doing, before it reaches the master's table. This, however, is irrelevant to the subject before us. In justice to Tull, I will give his words on the subject of hoeing in dry weather, at p. 27, 28.: -" Dews moisten the land when fine. Dig a hole in the hard dry ground, in the driest weather, as deep as the plough ought to reach; beat the earth very fine, fill the hole therewith, and, after a few nights' dews, you will find this fine earth become moist at bottom, and the hard ground all round become dry.” From this he observes : “ In the driest weather, good hocing procures moisture to the roots; though the ignorant and incurious fancy it lets in the drought, and therefore are afraid to hoe their plants at such a time.” Although Cuthbert W. Johnston calls these enlightened observations, they are not very clear. Though it is said that vapour is absorbed by the soil, Tull's experiment does not prove it; for, if such were the fact, the soil would have been wet at the top instead of the bottom. The truth is, that the hole was a vent for the vapours to ascend from below. Upon this Tull might safely have founded his belief, that hoeing in dry weather gives moisture to the roots of young plants ; but there is danger, on the other hand, of letting too much escape. Young turnip plants can, perhaps, stand drought better than wet cold weather. This appeared by the bad crops on good land which retained moisture, and the good crops on poor land which did not, in Norfolk, in the year 18+1. As to the earth's absorbing vapour, it is not apparent in this case. I may be wrong here ; but I can safely say that the evaporation from the earth is far greater than any absorption by it. To illustrate this, there is no need of enquiry into the theory and phenomena of dews; it is enough to make the simple experiment of covering part of a seedlbed with a mat. The under side of the mat will be found wet, while the upper will remain dry, like the exposed surface of the bed. Tull did not
think the contrary : to test the thing, I gave a squirrel a dead swallow, and he soon devoured it. I repeated this with other birds, and the same thing always happened. Mr. Waterton can hardly object to what I have just stated, as he did to Mr. Coward, viz. You cannot judge of the real habits of an animal when it is in confinement;" for the squirrel in question was but a few days before a free denizen of the wood, and was well supplied with his favourite kind of food at the time he eat the birds. This squirrel soon got tame; also a female, which brought forth three young ones. This gave me an opportunity of observing their habits when young. At first they were helpless ugly creatures, blind four weeks and some days, and it was three weeks more before they began to frisk about. The nest was of loose construction, but soft and warm within, similar to those on trees, having an entrance in the side. Perhaps the reader is not aware that, when a squirrel's nest is disturbed, the mother will carry off the young to another one for safety: if once the hand has been in the nest, it is quite enough ; it is of little use to leave the young until they get more advanced in growth, for they are sure to be gone. I may mention a very simple plan to catch squirrels, when they happen to be on detached trees. Put a small wire noose on the end of a long pole like a fishing-rod; ascend the tree leaving a few gaping folks below, to prevent the descent of the squirrel ; with a deal of manæuvring try and put the noose over his head, and pull him gently down. Whoever is to get hold of him ought to be well provided with good gloves, otherwise he may have to repent of acting Jack Catch upon Mr. Squirrel. Perhaps Mr. Waterton may consider that I “ deserve a birch rod” for what I have said, as he thought the Wiltshire shepherds did who backed Mr. Coward in his belief of the carnivorous propensities of the squirrel; if so, I can only say what I have stated is correct.
Cossey Gardens, Jan. 3. 1843.
Art. VIII. On Grouping Trees in Parks and Pleasure-Grounds.
By R. Errington. Groups of trees, of considerable size, it is well known, are often planted in park and other open scenery, yet seldom have I seen it performed in a satisfactory way. I have noticed attempts of this kind, in which the trees being all of a size, and planted in the most circumspect way, at measured distances, would have led one to suspect they had been planned and planted by the carpenter.
No one, in my opinion, can plant a group of trees of considerable size, for immediate effect, without in the first place having a variety of heights disposed in a somewhat irregular way. Thick planting also must be had recourse to in many instances, or how shall the pendulous inclination of stems or branches be produced that gives graceful outline to the vista ?
The operator in this case must set aside the idea of planting for profit, for this is in some degree incompatible with the effect which is sought to be produced. I once saw a park in which grouping with large trees for immediate effect had been attempted to a very great extent, and it was in its results a most miserable failure ; the park was of immense extent, and presented in inany places rather agreeable folds of ground, which, although not possessing expression enough for the picturesque, would, by judicious planting, have produced considerable diversity. Groups here and there were attempted of some twenty or thirty trees scattered at about equal distances and of equal heights; their distance asunder was so considerable, that they could not be said to act in unison in producing effect. Added to this they had been planted without the necessary preparation of making the holes, &c.; for, the soil being a stiff retentive clay, and withal what is termed technically " thin-skinned," it could not be expected that trees of from 20 ft. to 30 st. high could flourish
without some previous preparation, and a little of what gardeners term “pruning.”
As regards planting groups for immediate effect, two things ae indispensably necessary, premising of course a judicious choice of situation. In the first place, capacious holes, adapted to the size of the tree, in making of which the upper or useful soil (if good), and the subsoil, should be thrown out in distinct heaps ; and last, though not least, sufficient
hoice of trees, both as regards height and form, reserving the most pendulous or inclining forms for the exterior of the groups.
If the subsoil be a retentive clay, the trees can of course make no root to be depended on below the general clayey surface, therefore what they cannot do below must be done above. In this case, the tree should be planted on a mound, and the true collar of the tree should be nearly a foot above the common surface. A small cart-load of prepared soil should be ready for each tree, composed of one half free loam, and one half vegetable matter, well blended ; this should be trimmed in amongst the fibres, and finally topped up with the original surface soil.
One of the most general faults that I am aware of, in the pleasure-grounds or shrubberies of the wealthy, is, the definite line formed by the sudden trans. ition from the pleasure-ground to the park. How frequently do we see a wire fence in this position; studded on the one side like a nursery, with a dense mass of chiefly evergreens, and either suddenly naked on the other side, or with a few large deciduous timber trees, which (in winter at least) form no bond of connexion! Sir Uvedale Price and others have said much about masses of holly and thorn as connecting links, and to break the browsing line; but how few attend to it, although few dispute the principle !
After all, the best groups are and can be made out of enclosed plantations, provided the “ painter's eye” has been at work. Here, by studying the varying forms, and seizing on what Price or some author calls “ accidents," graceful groups may be formed, full of intricacy, possessing a good sky outline, together with a gracefully fringed vista; and, if the position of the plantation has been well selected, groups complete in themselves as to form, and conducive to the general effect, may be produced.
Oulton Park, near Tarporley, Dec. 1842.
Art. IX. The Holly. By CHARLES WATERTON, Esq.
See, Winter comes to rule the varied year,
THOMSON. I am very partial to the holly, the yew, and the ivy. They give both food and shelter to the birds ; whilst their charming green foliage makes us almost forget that winter has set in. The holly claims my preference; for, in addition to food and shelter, it affords an impenetrable retreat to those birds which take up their quarters on its branches for the night.
Our ancestors knew and felt the value of the holly hedge, when the wintry blast whistled through the naked hawthorn. Hence they raised it as a barrier against the north ; and, on the breaking of the clouds at noon, they would resort to the protection which it offered, and there enjoy the sun's delightful presence. But modern innovation, which, in nine times out of ten, does more harm than good, seems to have condemned the holly hedge as a thing of stiff unsightly form, and in its vacant place has introduced a scanty sprinkling of isolated plants. I own that I am for the warm arboreous plan of ancient days; and thus I never pass a garden where yew and holly hedges grow without stopping to admire them, and then I proceed onwards with favourable notions of the owner's taste.
But, to the holly in particular. I am so convinced of its utility both to men and birds, that I have spared no pains in rearing it as a shelter from the cold, when Boreas, sure harbinger of storms, sweeps over the dreary waste.
The deeper and richer the soil, so much the better for the holly. Still, this favourite plant of mine will thrive almost in any soil, and even amongst the clefts of rocks, where there is scarcely any soil at all. Neither can any of the four rude winds of heaven affect the perpendicular growth of the holly tree, although they make an impression upon the sturdy oak itself. Thus, in this neighbourhood, whilst we see the elm and the beech leaning towards the east by the overbearing pressure of the western blast, we find that the holly has not given way to its impetuosity. Indeed, keep the roots of the holly clear of stagnant water, and you have little more to do, for it forms its own defence; and, moreover, it has one advantage over most other plants, namely, it can push its way successfully up amid surrounding shade and pressure. Its lateral branches, too, will take root, so soon as they come in contact with the soft soil beneath them.
If you place a young holly plant in a full-grown hawthorn hedge, it will vegetate in that incommodious site; and will manage, at last, to raise its head aloft, and flourish clear of all opposition. Thus, driven from his native home, perhaps through scarcity of wheat and whiskey, I have known a hardy son of Caledonia, although put in a situation apparently hostile to advancement either in fame or in fortune, maintain himself under fearful trials of adversity. In process of time, his perseverance and honesty were crowned with complete success. He took kindly to it, where you thought there would be no chance of ever getting on; but, by carefully watching his hour of advance, in the death of this competitor or in the negligence of that, this frugal, careful, steady emigrator from the North moved slowly onwards, till, in due good time, he passed through all surrounding difficulties; and, having got at last into the full sunshine of good fortune, he there took the lead on the high road to long expected wealth and honours.
He whose nerves would be affected at the sight of a straight holly hedge, might prevent their irritation by forming a crescent; say a segment of a circle to a radius of sixty yards. This would present a fine appearance to the eye, whilst it shut