Читать книгу Trees and Shrubs for English Gardens - E. T. Cook - Страница 14

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The art of pruning properly is one that is acquired by considerable practice and observation. The first is necessary that the actual work may be well and cleanly done, and it is only by observing the manner and times of flowering of the different trees and shrubs which go to constitute a well-kept pleasure-ground that the proper time to prune can be thoroughly understood. The manner of pruning varies considerably, some pinning their faith to a slanting cut towards a bud; some preferring a straight cut; while others again are content with simply slashing off the useless wood in the quickest possible manner. The former is the best method, as it does not present a surface for the lodgment of water, an important point with those shrubs that are of a pithy nature in the centre of the wood, as the presence of water will quickly cause the stems to rot and render the plant unsightly, even if it escapes serious injury. All stems that are an inch or more in diameter should be tarred over to keep out the wet, which either rots them directly or injures them indirectly by making a moist, congenial home for the various fungoid diseases to which so many of our exotic trees and shrubs are liable.

Many shrubs which have been in one place for some years, and which have become stunted or poorly flowered, are often given a new lease of life by a hard pruning in the winter, cutting away all the old wood entirely, and shortening the remainder. With a good feeding at the same time, they will throw up strong young shoots, full of vigour, which will bear fine and well-coloured flowers. Of course, a season of blooming will be lost by doing this, but it will be amply compensated for in after years by a healthy plant in place of a decrepit and unsightly one. The list appended includes practically every flowering tree and shrub hardy in this country, with the proper time of pruning it. Those not specified flower on the old wood.

When shrubs that by nature flower freely and are rightly placed with regard to soil and position refuse to bloom, root pruning will sometimes effect an alteration.

CEANOTHUS AZUREUS AT KEW.

Abelia.—This genus is barely hardy, and, in most localities, is usually pruned sufficiently or too much by frost. A moderate thinning of the shoots in spring is sufficient.

Acanthopanax.—There are three species of this genus hardy in this country, and of these A. ricinifolium requires no pruning beyond the cutting away of side-shoots to a single stem, as it attains the dimensions of a tree in Japan, its native country. A. sessiliflorum and A. spinosum are low-growing shrubs, and require an occasional thinning out, which is best done in late summer to allow the remainder to thoroughly ripen before winter.

CEANOTHUS AZUREUS, VAR. MARIE SIMON.

Actinidia.—A climbing genus, easily grown in warm, sheltered localities. They require very little pruning, but should be watched in spring when growth has commenced, or the twining shoots will get into a tangled and unsightly mass. Any growth not required should be cut away in winter.

Æsculus (Horse-Chestnut).—The common representative of this requires little or no pruning, but the other species are benefited by a thinning out of misplaced and useless branches in late summer to allow light and air to the centre of the tree. This is especially important to all the Æsculus in a young state. Æsculus parviflora should have a good thinning if the branches or suckers become at all thick, cutting all growths not required clean away from the base.

Akebia.—"Akebia quinata has flowered here, on an east wall, profusely for the last seventeen years, under the following pruning treatment: Cover the space allotted with the strongest shoots, and when new growth pushes from the eyes or spurs in the spring, do not regulate it, but summer-prune away all superfluous growth before it gets entangled. It is from 'spurs' that the flowers are produced, and the more these are kept clear, the more matured they become, and flower correspondingly."—E. M. in The Garden.

Amelanchier.—These should be pruned after the flowers are past, the removal of badly-placed and weakly shoots being all that is required. If the plants are becoming too large, they can be shortened back at the same time.

Amorpha.—If flowers are desired of A. fruticosa it should be kept thinned out, and not be cut back; but the flowers are not showy, and it is usually kept cut down every winter for the sake of its foliage. A. canescens should be cut down each spring to within two or three eyes of the old wood, as it flowers best on the young growth.

Andromeda.—The only recognised species of this genus is A. polifolia, which requires no pruning.

Aralia.—These should be kept to a single stem until they have attained a height of 6 to 8 feet, after which they may be allowed to branch, or be still kept to a single stem, as may be desired.

Arbutus.—An evergreen genus which requires no pruning.

Aristolochia.—A genus of climbers which succeed best if the shoots are not allowed to become too thick. The weakest should be cut away in winter.

Artemisia.—This genus is best known by its common representative, the Southernwood, but this and the other Artemisias should be cut down annually in a young state. When older, an occasional thinning out of the shoots in winter is sufficient.

Baccharis.—Of this, B. halimifolia flowers on the young wood and should be cut back annually, while B. patagonica should not be pruned at all.

Berberis.—Properly the Berberis requires no pruning, but the stronger-growing species, such as B. aristata, B. Lycium, B. virescens, B. vulgaris, &c., require an occasional thinning to keep them within bounds.

Berchemia.—A climbing genus which requires no pruning.

Bruckenthalia.—A dwarf-growing Ericaceous genus, the seed-pods of which should be removed as soon as the flowers are past, or the plants will be seriously weakened.

Bryanthus.—This should be treated the same as the last, which it somewhat resembles.

Buddleia.—Of these, B. variabilis, B. japonica, and B. intermedia flower on the young wood and require cutting back every winter to within two or three eyes of the old wood; B. globosa need not be pruned at all, except in a young state to keep it bushy; and B. paniculata only requires thinning out if it becomes too thick, which is not a very common occurrence.

Calluna (the Ling).—This and its numerous varieties should have the old flowers cut off as soon as they are past, and any long or straggling growth cut back at the same time.

Calophaca.—The solitary representative of this genus is rather inclined to become straggly if growing at all freely. When this is the case, the plant is benefited by the cutting back of the longer shoots in winter.

Calycanthus.—These require an occasional thinning of the branches, and any long shoots may be shortened with advantage.

Camellia.—These, which should be grown outdoors much more than they are, should be cut down if they get unhealthy or unshapely, which should be done in April. Otherwise no pruning is required.

Caragana.—Cut away all the straggling or misplaced branches.

Carmichælia.—Requires no pruning.

Cassandra.—See Calluna.

Cassinia.—These are grown more for their foliage than for their flowers, and should be cut down in the winter or early spring. This can be done annually or biennially according to whether the plants are growing strongly or not.

Cassiope.—See Calluna.

Catalpa.—This genus contains some of our handsomest flowering trees, all of which require careful pruning after the flowers are past, thinning out the weakly wood, and shortening any long branches.

Ceanothus.—Of these, C. americanus, C. azureus, C. integerrimus, and the garden hybrids, such as "Gloire de Versailles," "Marie Simon," "Ceres," &c., flower on the young wood, and should be cut back in spring, allowing only sufficient shoots to remain to form a well-balanced plant, and shortening them back to within two or three eyes of the old wood. The remaining species flower on the old wood, and merely require a shortening back of the stronger shoots and a thinning out of the weakly ones after the flowers are past.

Celastrus.—A climbing genus of strong and vigorous habit with showy fruits. They only require sufficient pruning in winter to keep them within bounds.

Cercis.—Requires no pruning, except such as may be necessary to make well-shaped plants, which should be done after flowering.

Chimonanthus.—The shoots of this should be shortened back after flowering, and if on a wall they should be spurred in.

Chionanthus.—See Cercis.

Choisya ternata.—This only needs thinning after the flowers are over and old wood removed.

Cistus.—Those which are hardy of this genus should be cut back each spring while in a young state, but when they have attained a flowering size no pruning is required. The cutting back of young plants induces a bushy habit, and also keeps them from weakening themselves by blooming and seeding.

Clematis.—The garden forms of this genus are divided into two sections, of which C. Jackmani, C. lanuginosa, C. Viticella, and C. aromatica (C. cærulea odorata) are the types of those which flower on the young wood, and which require cutting back close to the old wood in the winter; while C. florida, C. patens, and C. montana are the types of those which flower on the ripened wood of the previous year, and merely require a thinning out of weakly or unnecessary growth. Of species other than those mentioned above, C. Flammula, C. paniculata, and C. Vitalba flower on the young wood; and the remaining species are either herbaceous or flower on the old wood.

Clerodendron trichotomum.—Thin in spring.

Clethra.—These practically require no pruning, but long shoots may be shortened and weakly ones cut away with advantage.

Colutea.—These make better plants and flower later if they are cut back every winter. C. istria (a rare species) should not be cut down if flowers are desired.

Cornus.—The strong-growing shrubby Cornus, such as C. alba, C. Amomum, C. Baileyi, C. pubescens, and C. stolonifera require an annual thinning out, and those with brightly-coloured stems should be cut down every spring for their effect during the following winter. The remaining Cornus require little or no pruning.

Cotoneaster.—The large-growing species should be pruned in late summer, but only sufficiently to keep them within bounds; C. Simonsii requires cutting down annually while young to make it bushy, and the dwarf-growing kinds are best left alone.

Cratægus.—Keep the heads well thinned out to allow light and air to the centre of the tree. This should be done in late summer.

Cytisus.—These require very little pruning, with the exception of C. nigricans and C. capitatus, which flower on the young wood, and should be cut back annually. The other species and varieties make better plants if they are cut down each year while in a small state, but they should be left alone when they have attained flowering size.

Dabœcia (the Irish Heath).—Cut away all old flower stems in early winter.

Daphne.—Requires no pruning.

Desmodium.—These flower on the young wood, and should be cut nearly to the ground-line every spring.

Deutzia.—The old wood should be kept cut out of these, but no shortening of young shoots should be attempted.

Elæagnus.—These require an annual overhauling to keep them in good condition. This should be done in late summer, when the plants should be well thinned out, and all useless growth cut clean away.

Erica.—See Calluna.

Escallonia.—These are usually cut back by frost; but if they escape, E. rubra and E. punctata should have their long growths shortened back in spring, while the other hardy species need not be touched. E. macrantha simply needs thinning. All the smaller growths in the centre should be removed. E. philippiana does not like hard cutting back, but the old stumps must be cut out to make room for flowering wood.

PEARL BUSH (Exochorda grandiflora) SHOWING ITS NATURAL BEAUTY.

Exochorda.—These usually require no pruning, but if the plants are getting too large or unshapely, they should be cut back immediately after flowering.

Fatsia (Aralia Sieboldii).—This is usually cut by frost, but it stands a cutting back in spring, when new growth is soon made which will flower late in the following autumn.

Fothergilla.—Requires no pruning.

Garrya elliptica.—This always flowers on the previous year's wood. Need only be thinned to ripen the new growth.

Genista.—G. tinctoria flowers on the young wood, and should be cut back every spring. The other species of Genista should not be pruned, except to keep them in shape.

Halesia.—These are small trees or large shrubs, and should not be shortened back, but are improved if the growths are kept thinned out, which should be done after the flowers are past.

Halimodendron.—Requires no pruning.

Hamamelis.—Thin out regularly, as they are very apt to get thick and make weakly growths.

Hedysarum multijugum.—This flowers on the young wood, and should be cut back lightly each spring. The growths can also be pegged down to improve the plant, which is apt to get straggling.

Helianthemum.—Cut away all dead flowers and seed-pods after blooming.

Hibiscus.—Thin out in winter, but only shorten the longest shoots.

HYDRANGEA PANICULATA GRANDIFLORA (unpruned plant).

Hydrangea.—These flower best on young wood, and should be cut down in winter. H. paniculata grandiflora should always be cut back to within two inches of the old wood.

HYDRANGEA PANICULATA AND VAR. GRANDIFLORA.

Hypericum.—These should be cut back fairly hard in early spring, as they all flower on the young growth.

Indigofera.—Cut down every spring, as they flower on the young wood.

Itea.—Keep the growths thinned and cut away all old wood.

Jamesia.—This should be treated as the preceding.

Jasminum.—J. fruticans and J. humile are shrubs which should be thinned regularly; and J. nudiflorum and J. officinale are climbers, which should be spurred in after flowering.

Kalmia.—Remove seed-pods as soon as the flowers are past.

Kerria.—Cut away the old wood to encourage the young growths, which yield the best flowers.

Laburnum.—These should be thinned after flowering, cutting away the old or weakly wood, and shortening any long or straggling shoots.

Lavandula.—Cut away all flower-spikes after they are past.

Ledum.—Remove seed-pods after flowering.

Lespedeza.—See Desmodium, which it much resembles.

Leucothoë.—L. axillaris and L. Catesbæi flower much better if the old growths are removed and strong young shoots encouraged. The rest of the genus require no pruning.

Leycesteria.—Thin out old growths every spring.

Ligustrum.—L. ovalifolium and its golden variety are all the better for being cut down each winter while in a young state. The remainder merely require an occasional thinning.

Liriodendron.—Requires no pruning.

Lonicera.—The shrubby Loniceras are nearly all inclined to become very thick and full of weakly shoots if not well looked after. A thinning out should take place after flowering is past. The climbing Honeysuckles should only be pruned sufficiently to keep them within bounds.

Lycium.—These should be served the same as the shrubby Loniceras, but the operation should be performed in autumn or winter, as they flower practically all the summer.

Lyonia.—Requires no pruning.

Magnolia.—Generally speaking, the Magnolias should not be pruned, but cut away useless or decaying wood. Every wound, however small, on a Magnolia should be tarred over immediately.

Microglossa.—The solitary shrubby representative of this is M. albescens, which should be cut down in winter, as it flowers best on the young wood.

Myrica.—An occasional thinning is sufficient for this genus.

Myricaria.—Flowering on the young wood; this should be cut back every spring.

Neillia.—Thin out every year after flowering is past, cutting back the old wood to strong young shoots.

Neviusia.—This requires the same pruning as Neillia.

Notospartium.—Requires no pruning.

Nuttallia.—The single species of this flowers in February, and is improved by a good thinning out of the old wood when blooming is past.

Olearia.—Requires no pruning.

Ononis.—O. rotundifolia should be cut down every winter, as it flowers on the young wood. The remaining species flower on the older wood, and need not be touched.

Osmanthus.—These should not be pruned unless a particular shape is desired, when the plants may be clipped with a pair of shears in spring.

Oxycoccus.—This is a small creeping genus allied to Vaccinium, and requires no pruning.

Oxydendron.—Remove seed-pods.

Paliurus.—This attains the dimensions of a small tree, and should be kept trimmed up for that purpose.

Parrotia.—Thin out in spring after the flowers are past.

Paulownia.—Keep to a single stem to a height of about 8 feet, and then allow it to branch. If used for sub-tropical bedding, it should be cut down to the ground every winter.

Peraphyllum.—The solitary hardy species of this should not be pruned or disturbed in any way if it can be avoided.

Periploca.—A climbing genus which should be thinned out in winter, and only shortened back if necessary.

Pernettya.—These should not be pruned at any time.

Philadelphus.—These should be thinned after flowering, and the old wood cut back to strong young shoots. This is especially important with P. microphyllus, P. coronarius, and P. Lemoinei and its varieties.

Phillyræa decora (Vilmoriniana).—This well-known shrub needs no pruning.

Photinia.—Requires no pruning.

Pieris.—Remove seed-pods.

Potentilla.—Thin out after flowering, and shorten any old wood back to strong young breaks.

Prunus.—When young, all the members of this genus that are grafted or budded are improved by being cut back each spring until they have attained a fair size and shape. More especially is this the case with the Almonds, double-flowered Peaches, and the various flowering Cherries. When older, they need only be thinned and the flowering Plums and Cherries kept spurred in, but not too hard. Prunus japonica, P. nana, and P. triloba should be cut down to strong young breaks after flowering, the resulting wood bearing better flowers than the old wood. If any of these three latter are grown on a wall they should be spurred back hard after blooming.

Ptelea.—When young, trim these to form small trees, and do not allow them to develop into ungainly bushes. When older, they require an occasional thinning. P. trifoliata var. aurea, a golden form which is not grown so much as it deserves to be, should be cut back annually or biennially, the young wood being better coloured and bearing larger leaves than the old.

Pyrus.—The wild Pears should be spurred in the same manner as adopted for fruiting Pears, though not quite so hard. The wild Crab-apples, such as P. baccata, P. floribunda, P. spectabilis, &c., should be cut back every spring until they have formed well-balanced heads. Afterwards an annual thinning and a shortening of the longest shoots after flowering is sufficient. The remaining sections of Pyrus merely require an occasional thinning. P. japonica should be kept spurred in, whether growing on a wall or in the open, and in the latter case should not be allowed to become a mass of weakly shoots.

Rhamnus.—These should be thinned out if becoming too thick, but, as a rule, they require very little pruning.

Rhododendron (including Azalea).—Remove all seed-pods immediately the flowers are over, and any plants that are in a sickly condition should be cut down at the same time. By doing this a season or two of flower is lost, but it is practically the only means of bringing a weakly plant back to health again.

Rhodotypus.—Cut away old wood, and encourage the strongest of the young growths.

Rhus.—Keep these well thinned out, and destroy all suckers that appear, unless wanted for stocks. Gloves should always be worn when handling any of the Rhus, as the sap of all is poisonous to a certain extent. R. Toxicodendron is very poisonous. This should never be forgotten. If used for sub-tropical gardens cut down to within two eyes of the base. Select the strongest eye and rub the other off. Always use gloves in handling this shrub. It should never be planted where children have access to it.

Ribes.—All the Ribes are improved by being cut down annually while in a young state, but when older, a yearly thinning out of the old wood is sufficient.

Robinia.—This is a genus that requires very little pruning when the members of it have attained a fair size, an occasional thinning being all that is necessary. In a young state they require well staking, and the longest shoots should be shortened back, as many of them are top-heavy when young.

Rosa.—Although the various garden Roses come under this heading, yet they are a class apart, and are better dealt with by specialists. The species of Rosa do not require any shortening of their shoots, which should always be left at full length, but all of them should have an annual thinning out of the old wood, either cutting it right away or back to a young shoot. Some of the species are very prone to throw up suckers from underground sometimes to a considerable distance from the plant, and these should always be dug out and got rid of; merely cutting them off only producing two evils in the place of one.

Rubus.—This genus includes the Blackberry and Raspberry, and in a modified form the treatment accorded to them for fruiting is the best to employ with the ornamental Rubi, that is, all old wood that has flowered should be cut away and strong young canes encouraged. But while in the cultivation of the Raspberry only a few young canes are allowed to grow, in the ornamental species practically every young growth should be utilised. The double-flowered Rubi should have some of the old wood left, as they do not make so much young growth as the single ones do.

Santolina.—This is a dwarf-growing genus, the old flower-heads of which should be cut away as soon as they are past, and any long or straggling growths cut back at the same time.

Sambucus.—The elders require very little pruning as a rule, but the various cut-leaved, golden, or variegated forms are improved by being cut back annually. This will prevent them flowering, but as good foliage is required the loss of the bloom is a matter of little consequence.

Skimmia.—Requires no pruning.

Smilax.—The hardy species of this genus do not require any pruning if they have room to ramble. If space is restricted, thin out and shorten in autumn.

Sophora.—These should be kept thinned when they have attained flowering size; in a young state they should be kept to a single stem and induced to form well-shaped trees.

Spartium.—This should be cut back in a small state, but when older it requires no pruning whatever.

Spiræa.—Though all the Spiræas will flower on the old wood, the following are better for being cut back in winter to form young flowering shoots, viz., S. betulifolia, S. Douglasi, S. Foxii, S. japonica, S. Margaritæ, S. salicifolia, S. semperflorens, S. tomentosa, and many of their varieties and hybrids. The remaining Spiræas should be kept thinned out, and if any are making strong young breaks from the lower part of the plant they can be cut back to them after flowering.

Stachyurus.—This should be thinned out after flowering.

Staphylea.—S. pinnata should be kept thinned in late summer; S. colchica and S. Coulombieri require very little pruning, but if too tall or unshapely should be cut back immediately after flowering.

Stuartia	}	Require no pruning.
Styrax

Suæda.—Cut back occasionally to keep it from getting ragged.

Symphoricarpus.—Keep these well thinned out, which should be done in late summer.

Syringa (Lilac).—these should be kept free of suckers, especially the finer-named kinds, which are usually worked on stocks of the Common Lilac. In addition, disbudding may be practised with advantage in the spring, removing the majority of the blind shoots and any flowering or leading shoots that are misplaced or not required. This should be done twice or thrice at intervals of ten days or a fortnight.

Tamarix.—Cut back in a young state, but when older they should not be pruned at all.

Vaccinium.—The removal of any old or rough wood is sufficient for these.

Viburnum.—All the Viburnums grow thickly, and require an annual thinning.

Vitis.—The methods practised in growing Vines for fruit suit the ornamental species as well. If space is restricted they should be grown on the spur system, and if there is plenty of room then the extension system may be employed.

Wistaria.—These should be kept spurred in, with the exception of the leading shoots, which merely require a shortening in early spring according to the strength of the plant.

Xanthoceras.—Requires no pruning.

Zenobia.—These require no pruning as a rule, but occasionally a hard cutting back will induce healthy growth in place of a weakly one.

Thinning.—It will be gathered from these notes that thinning out only is needful in many cases. If judicious thinning were more practised English gardens would be more beautiful. It promotes internal growth and a wealth of flowers.

Pruning is frequently carelessly and ignorantly done, and this applies especially to forest trees. There are certain tools that may be used for the purpose. Under ordinary circumstances only a few are necessary, and these should always be of the best quality, sharp, clean, and always kept ready for use. Take the pruning knife for example. If this is not sharp it is impossible to make the necessary clean cut. The surface will be jagged and rough, and probably promote disease. Some prefer secateurs, and while admitting their value for pruning purposes, a good sharp knife is preferable; it is not so heavy, and does not tire the hand. There are several of these implements in the market, but the best that has come under my notice is the "improved double cutting"; it is easy to work and cuts clean. For standard trees use the "Standard Tree Pruner."