Cultivation of Hardy, Ornamental, Coniferous and Other Evergreens

Date Published: 
September, 1903
Original Author: 
John Dunbar
Original Publication: 
AACS Proceedings of the 17th Annual Convention

In the popular mind evergreens are usually associated with pines, spruces, firs and the like. In this brief paper we will call attention to some hardy ornamental evergreens other than the coniferous forms.

There is undoubtedly a particular value in any shrub or tree that will maintain a good normal green appearance in its leaves throughout the entire year in this latitude. The British Islands and some parts of Continental Europe, on account of the cool moist atmosphere that prevails, are admirably adapted to the cultivation and high development of many beautiful "flowering evergreens" that we cannot think of cultivating throughout the northeastern United States. We are, however, more than compensated by the abundant wealth of many deciduous trees and shrubs, which on account of our hot, almost tropical summers, abundant rainfall and cold winters which give a long period of rest, attain to a much greater floral perfection here than, they do in Europe. It may seem strange, however, that although numerous parts of the North American continent are the homes of many beautiful evergreens, that their successful cultivation is frequently attended with much difficulty under ornamental conditions. We will first consider the coniferous evergreens. Their cheerfulness throughout the dull winter months and the handsome comely forms of many of them, so strikingly apparent in the summer time, particularly in their youthful days and their general desirability at all times of the year, commend them to all planters wherever conditions are known to be favorable for their healthy growth and development, in parks, cemeteries and private grounds. They do not impoverish the soil around them nearly to the same extent as deciduous trees, their leaves are not troublesome in creating litter and they rarely are injured by violent storms. They can easily be restricted in growth and area if so desired, without much trouble, by disbudding and pinching, and this can be done so intelligently that the means employed to accomplish this end can hardly be detected.

Rochester being such a prominent nursery center for a great many years, coniferous evergreens among other things, have been more or less largely cultivated, handled and sold. The well known firm of Ellwanger & Barry during their long career have tested a large number of different kinds, from an experimental point of view and obtained much valuable information as to the most satisfactory species and varieties for planting in conditions of soil, temperature and moisture that obtain elsewhere similar to Rochester. For example, on the south side of their vineyard on Highland Ave. the Nordman and Cephalonian firs, over fifty feet in height and Lawson's Cypress nearly forty feet, are in good health, and planted nearly fifty years since, are among some of the important evergreens to be seen in their grounds.

Highland Park, which forms a part of the park system of the city of Rochester, contains an extensive pinetum covering an area of 20 acres. The soil is a very light sandy loam, on porous, gravelly subsoil. The nucleus of this collection was planted in the spring of 1896 and numerous accessions have been made since. No particular plan of planting in generic sequence has been adopted. The more rare and known tender kinds are planted in different situations and exposures to find out what suits them best. As every experienced planter knows, some evergreens are exceedingly capricious and what might strike a planter as an ideal "spot" for these particular subjects may subsequently show by their behavior to be unfitted for them, so we have adopted the plan of not having all our "eggs in one basket." Some species of doubtful hardiness such as Pinus Sabiniana, Libocedrus decurrens, Cedrus Deodara and C. Libanii have been under trial since 1898 and so far have behaved splendidly, but we cannot tell how soon a severe winter may occur and injure them severely. Pinus insignis, P. Pinea and Cupressus MacNabiana have been winter, killed.

The soil best adapted for almost all coniferous evergreens is a light sandy loam with good porous subsoil, which must be naturally or artificially well drained. It must not of course be understood that we recommend a poor soil, but whilst it should be light in texture, it should be rich enough to grow good wheat or potatoes. The best season for planting coniferous evergreens is a much discussed question. I have planted them at all seasons of the year, except when in full growth, with more or less success. In the months of August and September is a good time for planting, providing the ground has been well saturated with rains. I think on the whole I have had the best results by spring planting, just about the time when the buds begin to perceptibly swell. It is needless to say before a body of practical men such as we have here, that coniferous evergreens are much less tenacious of life than deciduous trees, and therefore the most scrupulous care should invariably be exercised in planting or transplanting to preserve the roots from exposure to the air. This gospel has been preached time and again, and no heterodox heresy will ever affect its validity. The different pines, spruces and firs perhaps show their greatest beauty in their youthful days. I mean by that before they attain anything like maturity. Therefore the preservation and retaining of the lower branches should be encouraged by all possible cultural means, This can be aided by an occasional stopping of the leader by cutting back to a bud in firs and spruces and allowing it only so much growth in a season, and disbudding the points of branches in May and June that extend too far beyond the general pyramidal outline. Under conditions where a highly gardenesque effect is desired the most dense pyramidal outlines can be produced in many firs and spruces by systematic judicious disbudding, and still look wonderfully naturalistic. It must be clearly understood that I do not here in any way allude to the topiary art of shearing or trimming with shears into any form whatever, for unless for hedge purposes, that is something to be despised.

In the Highland Park Pinetum very little disbudding has been done, as it is desirable in a collection of this kind to leave them as much as possible to natural development. The main attention has been given towards the preservation of the leaders and occasionally central buds have been repressed in branches of pines, spruces and firs where they extend too far.

Mulching is excellent treatment for young evergreens where it is practicable and I have elsewhere seen splendid results from it. With us this is impracticable, but we do the next best thing. The soil is kept thoroughly cultivated and stirred from eighteen inches to two feet from the extremities of the branches and this also saves them from possible damage from fires, which are sometimes liable to occur in the dry grass in early spring. Among the various insect pests that attack evergreens the two worst with us are Red Spider, and the Pine-Tree Blight, Eriosoma strobi. The red spider in a dry season will attack some of the spruces so badly as to seriously disfigure them. With an abundant supply of water under pressure applied frequently, Red Spider can be controlled, but that is seldom under command. The Pine-Tree Blight has a particular liking for the white pine and will cover the branches thickly, producing a white, downy like appearance.

It can be destroyed by any of the soap insecticides. Sometimes the white pine when apparently in the best of health and vigor will die with what seems like mysterious suddenness. This usually occurs, however, when it has been planted in a heavy, damp soil and is making a rank growth. In a light, well drained soil the causes that produce this sudden demise are rarely operative.

Among the different species of pines that are the most useful for ornamental and decorative planting, the white pine undoubtedly comes first. Our native red pine is excellent. The Bhotan, Corean, Thunbergs, Swiss Stone, densiflora and ponderosa pines we believe can be depended upon in sheltered situations. The dwarf Mugho pine and the variety known as rotundata are extremely useful and serviceable in many situations. The Austrian and Scotch pines are not generally long lived but they grow easily, are very accommodating, and we confess to having a tender regard for them.

The spruces are very attractive and among some of the best are our native white spruce and its blue form. The Oriental, Engelmans’, Douglas', Alcock's and of course the popular blue spruce, are all excellent. A spruce introduced fifteen or twenty years since from Southeast Europe, Picea Omorika, has great promise.

Our native hemlock spruce and its weeping form are indispensable, but although a native, do not plant it in bleak, cold situations or it will look forlorn. The Carolina and Patton's hemlock spruces are very promising. Albert's hemlock spruce from British Columbia and the Japanese species do not look very happy with us so far. Among the firs I have no hesitation in placing Abies con color from Colorado as one of the most decorative in these parts. Nordman's, Cephalonian (the latter will sometimes get scorched in a young stale by the winter's suns but it will soon outgrow it) and the Japanese brachyphylla and Veitch's firs, will, if planted in sheltered spots, be satisfactory. The balsam fir in Western New York looks wretched after fifteen or twenty years. The numerous forms of the native Arbor Vitae such as Hovey's, Siberian, compacta, Vervaeneana, Tom Thumb, globosa and minima, with their prim and stiff forms are useful in many situations.

The two best yews are the Japanese and the Canadian. The English Yew, with its numerous forms, is liable to get badly scorched in a severe winter.

The Nootka Sound Cypress, Cupressus Nutkaensis, appears to do well with us and is very ornamental. The Japanese Retinosporas are very unsatisfactory in Western New York

In the junipers we have some excellent evergreens. The red cedar or Virginia juniper is one of the most virile and hardy evergreens in existence. It will grow and look happy in the poorest soils and bleak exposures, and we have some pretty forms of it such as venusta, elegantissima and the glaucous variety is exceedingly handsome. The Savin juniper and its varieties tamariscifolia and alpina can be used with excellent results on banks and slopes, and in connection with rocky formations. The carpet juniper J. prost rata, and the Himalayan species J. squamata are perfectly hardy, and also excellently adapted for draping slopes and rocky banks.

The common juniper, J. communis, in its procumbent forms is very useful. The so called Irish juniper with us is useless, but the Swedish form we believe can be depended upon and the Japanese and Chinese junipers appear to be satisfactory.

In flowering and other evergreens that can be depended upon to be satisfactory in Western New York the list is small. Among the "flowering" evergreens no plants can compare to the chaste beauty of the Rhododendrons wherever they prove to be happy and healthy. In Western New York the cultivation of Rhododendrons cannot be said to have been successful, but this is more due to soil conditions than anything else. The soil is mainly limestone and it is well known that they will not thrive in soil containing lime. In limestone soil they will make a fairly good growth, but they seem to lack the necessary vigor to pass through the winter, as even when protected closely, they look unhappy when spring comes. Their cultivation, however, in Highland Park in excavated beds filled with humus or soil of a peaty nature has so far given excellent results. They grow freely, flower abundantly, pass through the winter without any scorching, and they are not coddled by close protection, other than that afforded naturally from the prevailing winds, and from the direct rays of the late winter's sun.

What is known as the Hunnewell list, which contains about twenty-five varieties, with Catawbiense blood, are all that can be used here.

The mountain laurel, Kalmia latifolia an excellent shrub, should always be used wherever it can be coaxed to grow but it will not thrive in lime. The narrow leafed form K. angustifolia is useful and the early flowering hardy species K. glauca is pretty in early spring.

Leucothoe Cateslxei, with its beautiful glossy leaves, is excellent for planting in quantity in sheltered situations.

Among the Andromedas, A. floribunda and the common A. polifolia are very satisfactory. The latter used in large quantities around the margins of ponds and lakes can be easily made to produce denser effects than it does in its native sphagnum bogs.

The native leather leaf, Cassandra calyculata can be coaxed to grow without much trouble, but it is not very decorative. The pretty little Labrador-Tea is difficult to handle. The Barberry, Arctostaphylos, when seen covering the ground with a dense carpet of green in a wild state in parts of Long Island and about the Atlantic Coast, is very attractive, but in our experience it takes unkindly to cultivation, and it is moreover hard to propagate.

Among the heaths Erica carnea, E. vagans and the Scotch heather in several forms, take kindly to cultivation and form real pretty clumps. The evergreen Euouymuses are very useful farther south, but the climbing radicans form is the only one of any account here. In the evergreen barberries aquifolium, fasicularis and the low growing repens are perfectly hardy, but they need to have natural protection from the late winter sunshine or they will get badly scorched. These evergreen barberries are very ornamental and cheerful in the winter months.

This is about the northern limit of the American holly Ilex opaca and it needs good natural shelter to look at all pleasing. The beautiful crenate holly from Japan grows slowly with us, but it is healthy enough and may form good bushes some day. The gorse or whin from Europe is useless.

Daphne cneornm under sheltered conditions forms a real pretty clump and the dwarf little sun rose, Helianthemum vulgare, is perfectly hardy and forms dense masses.

There are some pretty and useful forms of the common box (Buxus) such as naviculatis, Handsworthi and microphylla, which are quite hardy under partial shade.

A recently introduced form of the laurel from the Balkan Mountains, said to be very hardy, has been under trial in the Ellwanger & Barry nursery for some years and is reported by them to be very satisfactory. As a broad-leaved evergreen this should be very important.

In conclusion, outside the coniferous evergreens the number of flowering and other evergreens suitable for planting in ornamental grounds in this latitude is really not large and not sufficiently extensive, or of that nature so as to produce any marked or broad effect on our landscapes in this climate.

From the publication:
AACS - Proceedings of the 17th Annual Convention
Held at Rochester, NY
September 8, 9 and 10, 1903