|Standard Cyclopedia of Horticulture|
Hedges. Living green fences are used for two distinct purposes—defense and ornament. Ornamental hedges may be rendered defensive by stretching tightly two or three strands of barbed wire through the center of the hedge. So far, no plant has yet been tested that meets all the requirements of the farmer for a truly impassable barrier, although the Osage orange (Madura pomifera) possesses more recommendable features than any other hardy tree. This tree, however, is not hardy in the northernmost states. For regions south of Washington, D. C., Kentucky, and Missouri, Poncirus (or Citrus) trifoliata is of equal value. Both have the serious drawback of being subject to the attacks of the San Jose scale, but no satisfactory substitute has yet been found.
Next to these, perhaps, ranks the honey locust (Gledilsia triacanthos), with many warm admirers and advocates. The hawthorn of Europe (Crataegus oxyocantha) may not be planted in this country with much chance of success, owing to fungous enemies.
Crataegus Crus-qalli is fairly satisfactory, but is not likely to make a tight hedge close to the ground. Other large thorny shrubs also fail in important particulars.
A perfect thorn hedge requires unremitting care, and must conform to an established rule, the most important being entire freedom from weeds and a systematic pruning. The preparation of the soil for a hedge consists of thoroughly plowing and cultivating an area 6 feet wide and the length the hedge is proposed to extend; or else to dig a trench 2 feet deep and 2 or 3 feet wide, and fill it with good top-soil thoroughly enriched. If this space should be fertilized and cropped the year previous growth will be greatly accelerated.
Deciduous plants must have the tops well shortened, and the root-tips of all plants should be given a clean cut, as they are planted. The plants should be set in a single row as close together as they can be set. For hedges a foot high or less, the plants should not be over 4 inches apart. For hedges 3 or 4 feet high, the plants should be 6 inches to a foot apart.
The double row, as formerly advised by some growers, is now practically obsolete and justly so, being difficult to cultivate and preserve free from weeds. The single row gives the plants a chance to be somewhat balanced, as the two opposite sides will have nearly equal freedom to develop.
A trench or furrow is opened through the center of the cultivated strip of a sufficient depth to admit the roots without bending. In setting, the soil must be made firm with the aid of a rammer, a practice unexcelled for aiding growth, and, indeed, preserving plant- life after removal. Pruning is simply an annual necessity from the first, excepting when the hedge is intended to be plashed, and even in such cases, after the laying process, pruning must never be omitted during summer. This work is greatly accelerated and consequently cheapened by shearing when the plants are young and tender, say during the month-of July.
As to the best outline, a plain triangle, or what may be more slightly, the curvilinear or Gothic arch, is desirable, and a flat top is to be discouraged, as a body of snow lodged on it invariably injures the symmetry and beauty of any hedge. Another advantage of the triangular and Gothic arch types is that the sun can better reach the bottom of such hedges and keep them covered with foliage down to the ground. A rectangular hedge is liable to have bare spots at the base, while a hedge wider at the middle or top than at the bottom, is almost sure to be without foliage near the ground.
Material available for defensive hedges has already been discussed. For ornamental hedges, there are a large number of plants available, both deciduous and evergreen. Of these the half-evergreen California privet (Ligustrum ovalifolium) is probably more largely used than anything else, and in the eastern United States possibly more largely used than all other material combined. Its advantage over its competitors is its low first cost, and its responsiveness to pruning and training. These are offset by its liability to kill to the ground every few years, even toward the South. Probably the best hedge plant, all things considered, is Thunberg's barberry (Berberis thunbergii).
Of the evergreen hedges, the arbour-vitae; (Thuya occidentalis) is one of the most widely adaptable and deservedly popular. Hemlock (Tsuga canadensis) makes one of the handsomest but it succeeds in a comparatively restricted area. Its reputation as a slow grower should not prevent the box being more largely planted than it is. The Monterey cypress is much used as a hedge in California. There are many other evergreens that may be used to advantage.
Among the deciduous flowering plants are a great many that are desirable. A discussion of a few of these is included in the list that follows.
Where room at all permits, mass plantings or even untrimmed tree rows are better than a high hedge for barriers and screens. Plants with variegated or unusually colored foliage should be avoided for hedges.
The most serious annoyance to the hedge-grower is the presence of unwelcome woody vines, such as poison ivy (Rhus toxicodendron), Japan evergreen honeysuckle (Lonicera japonica), and so on, and the only remedy- is persistently to remove them by hand as soon as discovered. The attacks of insects may be treated similarly to those which injure other trees and shrubs.
Material especially adaptable for hedges.
Abelia grandiflora. Broad-leaved evergreen. Suitable for hedges up to 4 feet. Not hardy north of Washington and St. Louis.
Acer campestre. Deciduous. Adapted for hedges from 4 to 10 feet high in the northern half of the United States.
Azalea (Rhododendron) amama. Evergreen. Good for hedges up to 2 feet. Good as far north as New York, Philadelphia, Cincinnati, and St. Louis. Attractive foliage and showy flowers.
Berberis thunbergii. Deciduous, thorny, slow-growing. Cannot be reued on for hedges over 4 feet high. Adapted to all sections of the united States, except the non-irrigated arid regions. Responds to pruning, but makes a more attractive hedge when shears are not used. Naturally makes a tight bottom. Foliage small and most attractive. Bears annual crops of scarlet berries that hang on all winter, even in the South. Will grow within reach of salt-water spray. The best of the deciduous ornamental hedge plants, and has no superior in any class.
Berberis vulgaris. Deciduous, thorny. Useful for hedges from 3 to 6 feet high. Adapted to the northern half of the United States. Not so tight and compact as the foregoing. Bears berries that hang on half the winter. There is also a purple-leaved variety.
Bums sempervirens (boxwood; tree box). The box of colonial gardens. Evergreen; slow-growing; adapted for hedges up to 20 feet. Thrives as far north as central New York, southern Ohio, and Missouri. Stands shearing well. Probably the best evergreen hedge- plant in the regions in which it grows.
Buxus suffrulicosa (dwarf box). Evergreen. Suitable for use where a small hedge of the last-mentioned could be used.
Carpinus caroliniana (hornbeam). Deciduous. Good for hedges up to 10 feet. Makes a dense, strong hedge. Suitable for use as far south as Virgjnia and Kentucky.
Carpinus Belulus. Same adaptabilities as the last.
Chaenomeles japonica (Japonica; Japan quince). Deciduous; somewhat spiny. Grows North and South and even ill comparatively dry regions. Boy- and dog- proof. with handsome flowers. Somewhat subject to an Jose1 scale. Excellent.
Cinnamomum camphora (camphor tree). Broad- leaved evergreen for high or low nedges. Hardy only near the coast from Charleston, South Carolina to Texas.
Crataegus crus-galli (cockspur thorn). Deciduous. Has long spines. Can be used all over the country, except in the arid regions, but it is best adapted to the North. Flowers and fruits both attractive. Needs careful pruning when young to keep sides clothed to the ground.
Cralxgus oxyacantha. Similar to above. Not quite so dense a grower, but rather more showy flowers and fruits.
Deutzias. Deciduous, flowering shrubs of various heights from 30 inches to 6 feet, making rather loose hedges. Especially handsome when in flower. Some varieties hardy as far north as Chicago and northern New York; others only as far as St. Louis and New York City.
Elaeagnus angustifolia. Deciduous. Adapted for hedges or low windbreaks to a height of 20 feet. Thrives in all parts of the United States. One of the best for the semi-arid regions. Summer fruits attractive.
Elaeagnus parvifolia. Deciduous. Similar to the preceding, but not so widely adaptable.
Evonymus japonica. Broad-leaved evergreen. Useful for hedges up to 3 or 4 feet at its northern limits and double that height in the South. Occasionally winterkills as far north as Philadelphia and Cincinnati but well adapted for regions farther south. There is a variety with yellow-edged leaves.
Fagus sylvatica (beech). Deciduous. Suitable for high hedges or screens. Thrives in the northern half of the country.
Gardenia jasminoides (Cape jessamine). Evergreen. Flowering. Used for hedges up to 5 feet. Hardy in South Carolina, Georgia and the states bordering on the Gulf of Mexico.
Glediisia triacantlios (honey locust). Deciduous. Thorny. A good defensive hedge; succeeds over the whole United States. Especially valuable in the semi- arid regions and beyond the northern limits of the Osage orange (Madura maculata).
Hibiscus syriacus (rose of Sharon). Deciduous. Flowering. Useful for hedges and screens under 10 feet where an open bottom is not objectionable. Will grow successfully except in the most northern tier of states. Transplant only in spring where the ground freezes in winter.
Ilex Aquifolium (English holly). Broad-leaved evergreen with spiny leaves. Useful for hedges from 2 to 6 feet. Desirable south of Philadelphia and St. Louis. There are many varieties. Handsome.
Ilex crenata (Japanese holly). Broad-leaved evergreen. Leaves smaller than either the preceding or following species and without spines on the leaves. Good for hedges not exceeding 4 feet. Hardy except in the extreme northern states.
Ilex opaca (American holly). Broad-leaved evergreen with spiny leaves. Useful for hedges and screens up to 30 feet. Native near the coast from New Jersey southward and along the Gulf of Mexico. Will grow inland on light soils and thrives on poor ground. Pistillate plants filled with scarlet berries all winter.
Juniperus virginiana (red cedar). Coniferous evergreen. Adapted for hedges and screens up to 30 feet. Thrives almost everywhere. There are several forms in cultivation, but the type is most suitable for hedges.
Ligustrum amurense (Amoor River privet). Broad- leaved evergreen. Leaves smaller than L. japonica or L. ovalifolium. Better for hedges than L. ovalifolium. Hardy as far north as Virginia and Missouri. Ligustrum Ibota. Deciduous. Adapted to hedges 10 feet and under. Hardy except in the most northern sections. Var. regelianum. Dwarf. Makes hedges 4 feet and under. Filled with blue berries all winter. Ligustrum japonicum. Broad-leaved evergreen. Useful for hedges up to 6 feet. Not reliably hardy as far north as Washington, D. C., and St. Louis.
Ligustrum ovalifolium (California privet). Broad-leaved half-evergreen shrub. Useful for hedges from 6 inches to 12 feet. Tops liable to freeze to the ground every few years as far south as North Carolina and Oklahoma. Rapid grower. Stands 'pruning well and needs it frequently. Ranks with dwarf box as a low edging for flower-beds, except it requires weekly or fortnightly pruning. Its low first cost has led to its use in many places where other plants would have been more attractive and more economical. Thrives near saltwater, even within reach of the spray.
Madura pomifera (Osage orange). Deciduous. A defensive hedge. Hardy as far north as central New York and Nebraska. Subject to attacks of San Jos6 scale.
Osmanthus (Olea) fragrana (sweet olive). Broad-leaved evergreen, bearing sweet- scented flowers. Adapted to low hedges in the Gulf states and as far north as Wilmington, North Carolina, on the Atlantic coast.
Osmanthus aquifolium. Broad-leaved evergreen. Much like Ilex Aquifolium in general appearance, but blooms in late summer. Has showy winter berries on pistillate plants. Sometimes winterkills as far north as Washington, D. C., and St. Louis.
Picea alba (white spruce). Coniferous evergreen. Formal in habit. Good for high hedges and screens. More pleasing in color than the next species. Good for the northern hah" of the country even in comparatively dry regions.
Picea excetsa (Norway spruce). Coniferous evergreen. Same adaptability as the last and more used than it, but not so desirable.
Pittosporum tobira. Broad-leaved evergreen. Thrives in the South Atlantic and Gulf states.
Poncirus trifoliata (hardy orange). Almost evergreen South; deciduous in its northern range. Spiny. Good for defensive hedges from 3 to 10 feet high. Large glossy foliage. Attractive. Succeeds as far north as Philadelphia and Cincinnati. Subject to San Jos6 scale. Populus nigra var. fastigiala (Lombardy poplar). Deciduous. Adapted for hedges and screens up to 30 feet. Useful in the northern hah" of the United States. Prunus caroliniana (mock orange of the South). Broad-leaved evergreen adapted to the southern states from Norfolk south. Excellent.
Retinosporas. Coniferous evergreens adapted to hedges under 6 feet. Suitable for use south of the 40th parallel and in special localities north of it. Not suitable for the semi-arid regions.
Rhamnus calharlica. Deciduous. Good for hedges to 6 feet. Most useful in the northern half of the country. Rosa rubiginosa (sweetbriar rose). Deciduous, thorny. Adapted for hedges up to 3)-^ feet. Thrives everywhere except in the most arid sections. It bears attractive flowers and hips, but does not make so close a hedge as many other plants.
Rosa rugosa. Deciduous, thorny. Adapted for hedges of 5 feet and under. Will grow both North and South and is promising for use in the semi-arid regions. Flowers and hips both attractive. For a summer hedge it is excellent, but its whiter appearance is not hedge-like although quite effective as a deterrent to intruders.
Spiraeas. Deciduous shrubs. A group of beautiful flowering shrubs adapted for use as low hedges North and South and promising for use in the semi-arid regions. Spiraea bumalda var. Anthony Waterer would make a hedge 2 feet high with flat topped pink blossoms in early summer. Spirsea thunbergii grows 5 feet high with white flowers in early spring. It has fine foliage, but the tips of the branches are apt to winterkill even as far south as Virginia and Missouri. Spiraea Van Houtiei is white, about intermediate between the other two in season. The finest of the spireas hi flower. It has beautiful foliage and is adapted for hedges.
Syringas (lilacs). Deciduous shrubs. A group of beautiful flowering shrubs adapted to all parts of the United States, some species being especially promising for the semi-arid regions. Syringa amurensis is especially well adapted for use on the Great Plains. It grows 10 feet high. Syringa persica is about as adaptable as the last but more dwarf, growing but 5 feet high. Syririga vulgaris has many named varieties, both double and single, in a wide range of colors and habit of growth.
Thea bohea (Chinese tea plant). Broad-leaved evergreen. Low-growing. Blooms in winter. Useful near the seacoast from Charleston, South Carolina, to Texas.
Thuya occidentalis (arbor-vitae). A coniferous evergreen with many forms, of which the type is as useful as any for hedge purposes. Adapted to all sections of the United States. Much used and deservedly so.
Thuya orientalis (Chinese arbor-vitae; Biota). Coniferous evergreen with many forms. Useful over nearly the same range as the foregoing.
Tsuga canadensis (hemlock). Coniferous evergreen. Useful for low and high hedges and screens to 50 feet. Adapted to moist and medium soils in the northern half of the United States. One of the handsomest in the regions in which it thrives.
Viburnums. Deciduous and evergreen shrubs. Many-berried and handsome. Among the desirable deciduous species that thrive all over the United States except in the extreme South and the drier regions are V. cassinoides, V. dentalum, V, nudum, V. Opulus, V. plicatum, and V. prunifolium. The handsome evergreen species V. Tinus is tender and not likely to succeed north of the Carolines and the Gulf States, but where it succeeds it is most desirable. F. L. Mulford.
Hedraeanthus, Hedranthus: Wahlenbergia.