Chapter 2

Fig. 10. Bulb of Lilium candidum.

Bulbs often break up or divide themselves into two or more nearly equal portions, as inLilium candidum, shown one-third natural size inFig. 10. The partsmay be separated and treated as complete bulbs for purposes of propagation. This division or separation of bulbs proceeds in a different manner in nearly every species, yet it is so obvious that the novice need not be perplexed by it. Almost any breaking apart of these loose bulbs, if only a “heart” or central axis remains in each portion, is successful for purposes of slow multiplication; but when flowers are desired it is usually inadvisable.

Bulbous plants multiply most easily by means ofbulbels—often also called bulbules and offsets—or small bulbs which are borne about a large or mother bulb. In some lilies, asLilium candidum, the bulbels form at the top or crown of the mother bulb, and a circle of roots will be found between them and the bulb; in others, asL. speciosumandL. auratum, they form on the lower part of the flower stalk. In some species the bulbels are few and very large, or even single, and they bloom the following year. In such cases the bulb undergoes a progressive movement from year to year after the manner of root-stocks, the bulb of one year forming a more or less distinct one above and beyond it which continues the species, while the old one becomes weak or dies. This method of bulb formation is seen in the cut ofLilium pardalinum,Fig. 11. In the hyacinth the bulbels form at the base of the bulb.

Fig. 11. Bulb of Lilium pardalinum.

Bulbels vary greatly in size and frequency in different species. Sometimes they are no larger than a grain of wheat, and in other plants they are as large as hickory-nuts. In some species they are borne habitually underneath the scales of the mother bulb. These bulbels are often removed when the mother bulbs are taken up, and they are usually planted in essentially the same manner as the bulbs themselves, although it is desirable to place them, at least for the first year, in a bed or border by themselves. Or if they are especially small and delicatethey may be planted in pots or flats and be treated about the same as single eye cuttings. In some lilies the bulbels are allowed to remain attached and the whole mass is planted in the fall in close drills. Sometimes the larger lily bulbels will produce flowers the following season, but they usually require the whole of the season in which to complete their growth. The second fall they are ready to be permanently planted. Bulbels of some plants require a longer time in which to mature into bulbs.

Fig. 12. Cut Hyacinth Bulb.

Fig. 13. Hollowed Hyacinth Bulb.

Bulbels are often produced by an injury to the bulb. Growth of stem and leaves is prevented or checked and the energy is directed to the formation of minute buds, or bulbs, in the same manner as adventitious buds form upon a wounded stem. Advantage is taken of this fact to multiply some bulbous plants, and in the case of the hyacinths, at least, the mutilation of bulbs for this purpose is practiced to a commercial extent. Hyacinth bulbs are cut in two, or are slashed in various ways. The favorite method is to make two or three deep transverse cuts into the base of the bulb. The strongest bulbs should be chosen and the operation is performed in spring or early summer when the bulb is taken up. The bulbs are sometimes hollowed out from the under side for half or more of their length. This operation is sometimes performed later in the season than the other, and precaution should be exercised that the bulbs do not become too moist, else they will rot. Hollowed bulbs should be well dried before being planted. Both methods of preparing hyacinth bulbs are shown in Figs.12and13which are adapted from Gardeners' Chronicle.Fig. 14shows a portion of the base ofa cross-cut bulb, with the adventitious bulbels. The mutilated bulbs are stored during summer, and are planted in fall or spring. The wounded bulbs produce very little foliage, but at the end of the first season the bulbels will have formed. The bulbels are then separated and planted by themselves in prepared beds. Several years are required for the bulbels to mature into flowering bulbs. Some of the strongest ones may produce flowering bulbs in three years, but some of them, especially those obtained from the hollowed bulbs, will not mature short of six years. This method of propagating hyacinths is confined almost entirely to Holland.

Fig. 14. Cross-Cut Bulb.

The scales of bulbs are often employed to multiply scarce varieties. From ten to thirty of the thicker scales may be removed from the outside of the bulb without serious injury to it. These are treated in the same manner as single eye cuttings. They are usually handled in flats or propagating-frames, and are pressed perpendicularly into a light and loose soil—half sharp sand and half leaf-mould—for nearly or quite their entire length, or are scattered in damp moss. Keep the soil simply moist, and for hardy and half-hardy species keep the temperature rather low—from 45° to 60°. Slight bottom heat may sometimes be given to advantage. In from three to ten weeks a little bulbel, or sometimes two or more, will appear at the base of the scale, as shown inFig. 15.

Fig. 15. Bulb-Scale.

These pots or flats may be plunged out-doors during summer if the planting was done in winter, or the scales may be potted off or transferred to the open border as soon as rootlets have formed. It is the common practice with most hardy species to allow the scales to remain in the original flats during summer and to cover them the next fall, allowing them to remain out-doorsover winter. The succeeding spring they are shifted into a bed or border, and by the next fall—having had two summers' growth—most species will be ready for permanent planting in the flower border.

Abulbletis a small bulb borne entirely above ground, usually in the axil of a leaf or in the inflorescence. Familiar examples occur in the tiger lily and in “top” onions. In the former instance the bulblets are direct transformations of buds, while in the onion they are transformed flowers. It is impossible to draw any line of separation between bulblets and buds. In some plants, certain buds detach themselves and fall to the ground to multiply the species. Sometimes these buds vegetate before they fall from the plants, as in the case of various ferns. For purposes of propagation, bulblets are treated in the same way as bulbels, and like them, they reproduce the variety upon which they grow. They will develop into full grown bulbs in from one to three years, according to the species.

Fig. 16. Gladiolus Corm.

Acormis a bulb-like organ which is solid throughout. Familiar examples occur in the gladiolus and crocus. Cormous plants are multiplied in essentially the same manner as bulbous species. As a rule, a new corm is produced each year above the old one, and this commonly bears flowers the following season. This renewal is well shown in the gladiolus,Fig. 16. The illustration shows a gladiolus bottom, half size, when taken up in November. At the base are seen thewithered remains of the corm which was planted in the spring, and above it the new corm which will furnish bloom the following season. A number ofcormelsor “spawn” have also appeared. These may be planted out in a border or bed and will produce mature bulbs in one or two seasons. The larger ones, under good treatment, will often produce bulbs an inch in diameter the first season. Some growers keep the cormels a year and a half before planting them out, as they are thought to vegetate more evenly under such treatment; in this case they should be placed in sand to prevent too great drying out.

Adventitious cormels may be produced by various methods of wounding the mother corm, and this practice of exciting them is often necessary, as some varieties do not produce cormels freely. Each bud on the top or side of the corm may be made to produce a separate corm by cutting a deep ring around it, so as to partly divide it. Or the corm may be directly cut into as many separate pieces as there are buds or eyes, after the manner of cutting potatoes, but these pieces are usually handled in flats where temperature and moisture can be controlled. Almost any injury to such vigorous corms as those of the gladiolus and crocus will result in the production of cormels, if care is taken that the corms do not become so cold and wet that they will rot.

Atuberis a prominently thickened portion of a root or stem, and it is usually subterranean. The potato, sweet potato and dahlia furnish good examples. Tuberiferous plants are multiplied by planting these tubers whole, or the tubers may be cut into small portions as described inChapter IV, in the descriptions of cuttings. In hardy species, the tubers may be allowed to remain in the ground during winter, but they are generally dug in the fall and stored in a dry and cold place, but where they will not freeze.

Anoffsetis a crown or rosette of leaves, usually borne next the surface of the ground, which detaches itself and forms an independent plant. The best examples occur in the house-leeks, plants which are more familiarly known as “hen and chickens” and “man and wife.” These offsets take root readily, and in propagating there is no other care necessary than to remove and plant them.

Acrownis a detachable portion of a root-stock bearing roots and a prominent bud. Rhizomes or root-stocks multiply individuals and extend the distribution of the species by means of a progressive movement of the crowns. The root-stock grows during summer, and at the end of the season each branch develops a strong terminal bud which usually produces a flowering stem the following season. The root-stock gradually dies away at its old extremity, and in a few years a single individual gives rise to a considerable patch. This is well shown by the common May-Apple or podophyllum.

Fig. 17. Lily of the Valley Crown.

In some species these crowns are removed in the autumn and are planted and handled in much the same manner as bulbs. The crown or pip of the lily of the valley, shown half size inFig. 17, is obtained in this manner.

CHAPTER III.

LAYERAGE.

Layerage.—The operation or practice of making a layer, or the state or condition of being layered.

Layer.—A shoot or root, attached to the parent plant, partially or wholly covered with earth with the intention that it shall take root and then be severed from the parent.

Stolon.—A decumbent shoot which, without the aid of man, takes root and forms an independent plant.

Many plants habitually propagate by means of decumbent shoots and runners. These shoots become more or less covered with earth or leaves, and roots are emitted, usually at the joints. In many cases, the old shoots die away and an entirely independent plant arises from each mass of roots. In other plants, the shoots remain attached to the parent, at least for a number of years, so that the plant comprises a colony of essentially distinct individuals. Great numbers of plants which do not propagate naturally by means of layers are readily increased by this means under the direction of the grower. In most cases it is only necessary to lay down the branches, cover them with earth, and allow them to remain until roots are well formed, when they can be severed from the parent. Layering is one of the simplest methods of propagation, as the mother plants nurse the layer plants until they can sustain themselves. It is a ready means of multiplying hard-wooded plants which do not grow well from cuttings.

All vines, and all plants which have runners or long and slender shoots which fall to the ground, may be multiplied readily by layerage. Among fruits, the black-cap raspberry is a familiar example. The canes of the current year bend over late insummer and the tips strike the earth. If the tip is secured by a slight covering of earth, or if it finds lodgment in a mellow soil, roots are emitted and in the fall a strong bud or “crown” or “eye” is formed for next year’s growth. The parent cane is severed in the fall or spring, some four or six inches above the ground, and an independent plant, known as a “root-tip,” as shown inFig. 18, is obtained. In this instance, as in most others, it is immaterial at what point the parent stem is severed, except that a short portion of it serves as a handle in carrying the plant, and also marks the position of the plant when it is set. The black raspberry propagates itself naturally by means of layers, and it is only necessary, in most cases, to bring the soil into a mellow condition when the tips begin to touch the ground in order that they may find anchorage. This layering by inserting the growing point has the advantage of producing very strong “crowns” or plants in autumn from shoots or canes of the same year, and it should be more generally practised. Even currants, gooseberries, and many other plants can be handled in this way.

Fig. 18. Raspberry tip.

Fig. 19. Covered Layer of Viburnum.

In most cases of layerage it is necessary to lay down the branches and to cover them. The covering may be continuous, as inFig. 19,or it may be applied only to the joints or restricted portions of the shoot, as illustrated inFig. 20. In either case, the covering should be shallow, not exceeding one to three inches. If the shoot is stiff a stone or sod may be placed upon it to hold it down; or a crotched stick may be thrust down over it, as in the “pegging down” of propagators.

Fig. 20. Layered Shoots.

The strongest plants are usually obtained by securing only one plant from a shoot, and for this purpose the earth should be applied only at one point, preferably over a bud somewhere near the middle of the shoot. If the buds are close together, all but the strongest one may be cut out. If more plants are desired, however,serpentine layeringmay be practiced, as shown at A inFig. 20. The shoot is bent in an undulating fashion, and from every covered portion roots will form and a plant may be obtained. The covered layer also possesses the advantage of giving more than one plant, but the roots are apt to form so continuously that definite and strong plants are rarely obtained; these rooted portions may be treated as cuttings, however, with good results. The grape is sometimes propagated by serpentine layering.

Stiff and hard-wooded plants do not often “strike” or root readily, and in order to facilitate rooting the branch is wounded at the point where a new plant is desired. This wounding serves to induce formation of adventitious buds at that point, and to check the growth of the branch at the tip. It is a common practice to cut the branch about half in two obliquely, on the lower side. This operation is known as “tongueing.” "Ringing" or girdling, twisting, notching, and various other methods are employed, none of which, perhaps, possess any peculiar advantages in general practice. Some propagators cut all the buds from the covered portion. In this case the free and protruding end of the layer is expected to form the top of the new plant. “Arching,” or very abrupt bending, as in serpentine layering, serves the same purpose and is the only attention necessary in most vines.

When large numbers of plants are desired, as in commercial nurseries, it is often necessary to cut back the parent plant to the ground, or very nearly so, for the purpose of securing many shoots fit for layering. A plant which is cut back in the spring will produce shoots fit for layering the following spring; or some species will produce them in abundance the same year if layers of green or immature wood are desired. These parent or stock-plants are called “stools” by nurserymen.

Fig. 21. Mound Layering of Gooseberry.

In many species layerage is performed to best advantage by heaping earth over the stool and around the shoots. This is known asmoundorstool layering. The shoots send out roots near the base and straight, stocky plants are obtained. The English gooseberries are almost exclusively propagated in this manner in this country.Fig. 21shows a row of mound-layered gooseberries. The shoots are allowed to remain in layerage two years, in the case of English gooseberries, if the bestplants are wanted, but in many species the operation is completed in a single season. Quinces and Paradise apple stocks are extensively mound-layered. The practice is most useful in those low plants which produce short and rather stiff shoots.

As a rule, the best season for making layers is in spring when the leaves are forming. Rooting progresses rapidly at that season. Many plants “bleed” if layered earlier in the season. Hardy shrubs may be layered in the fall, either early or late, and if an incision is made, a callus will have formed by spring. If rapid multiplication is desired, the soft and growing shoots may be layered during the summer. This operation is variously known as “summer,” "herbaceous," “green” and “soft” layering. Comparatively feeble plants usually result from this practice, and it is not in common favor.

Fig. 22. Pot layerage.

Pot layering,circumposition,air layeringandChinese layeringare terms applied to the rooting of rigid stems by means of surrounding them, while in their natural position, by earth or moss, or similar material. The stem is wounded—commonly girdled—and a divided pot or box is placed about it and filled with earth (Fig. 22). The roots start from above the girdle, and when they have filled the pot the stem is severed, headed back, and planted. Pot layering is practiced almost exclusively in greenhouses, where it is possible to keep the earth uniformly moist. But even there it is advisable to wrap the pot in moss to check evaporation from the soil. Some plants can be readily rooted bywrapping them with moss alone. Pot layering is employed not only for the purpose of multiplying plants, but in order to lower the heads of “leggy” or scraggly specimens. The pot is inserted at the required point upon the main stem, and after roots have formed abundantly the top may be cut off and potted independently, the old stump being discarded.

Fig. 23. Layering pot.

Fig. 24. Layering cone.

Fig. 25. Layering cup.

Fig. 26. Layering cup.

Fig. 27. Compound layering pot.

The French have various handy devices for facilitating pot layering.Fig. 23shows a layering pot, provided with a niche in the side to receive the stem, and a flange behind for securing if to a support.Fig. 24represents a layering cone. It is made of zinc or other metal, usually four or five inches high, and is composed of two semi-circular wings which are hinged on the back and are secured in front, when the instrument is closed, by means of a hinge-pin. A cord is inserted in one side with which to hang it on a support. A cup or pot with a removable side is also used. This is shown open inFig. 25and closed inFig. 26. An ingenious compound layering pot is shown inFig. 27. The main stem or trunk of the plant is carried through the large opening, and the branches are taken through the smaller pots at the side. Kier’s layering boxes or racks areshown in Figs.28and29. The trays are filled with earth and the branches are laid in through the chinks in the border and are treated in the same manner as ordinary out-door layers. These racks supply a neat and convenient means of increasing greenhouse plants which do not readily strike from cuttings.

It is well to bear in mind that when layers do not give strong plants, they can be divided into portions and treated as ordinary cuttings. This is an important operation in the case of rare varieties which are multiplied by means of soft or green layers, as some of the large-flowered clematises and grapes. The weak small plants are handled in a cool greenhouse or under frames, usually in pots, and they soon make strong individuals.

Fig. 28. Kier’s layering rack.

Fig. 29. Kier’s circular layering rack.

CHAPTER IV.

CUTTAGE.

Cuttage.—The practice or process of multiplying plants by means of cuttings, or the state or condition of being thus propagated.

Cutting.—A severed portion of a plant, inserted in soil or water with the intention that it shall grow; a slip.

Cuttings, particularly of growing parts, demand a moist and uniform atmosphere, a porous soil and sometimes bottom heat.

Fig. 30. Hand-glass.

Fig. 31. Small Propagating-box.

Fig. 32. Propagating-box.

Devices for Regulating Moisture and Heat.—In order to secure a uniform and moist atmosphere, various propagating-frames are devised. Whatever its construction, the frame should be sufficiently tight to confine the air closely, it should admit light, and allow of ventilation. The simplest form of propagating-frame is a pot or box covered with a pane of glass. To admit of ventilation the glass is tilted at intervals, or two panes may be used and a space be allowed to remain between them. A common bell-glass or bell-jar (clocheof the French) makes one of the best and handiest propagating-frames because it admits light upon all sides and is convenient to handle. These are in universal use for all difficult and rare subjects which are not propagated in large numbers. A hand-glass or hand-light (Fig. 30) answers the same purpose and accommodates alarger number of plants. A useful propagating-box for the window garden or amateur conservatory is shown inFig. 31. A box two or three inches high is secured, and inside this a zinc or galvanized iron tray,a, is set, leaving sufficient space between it and the box to admit a pane of glass upon every side. These panes form the four sides of the box, and one or two panes are laid across the top. The metal tray holds the soil and allows no water to drip upon the floor. One of the best boxes for general purposes is made in the form of a simple board box without top or bottom, and fifteen or eighteen inches high, the top being covered with two sashes, one of which raises upon a hinge (Fig. 32). Four by three feet is a convenient size. An ordinary light hot-bed frame is sometimes constructed upon the bench of a greenhouse and covered with common hot-bed sash. Propagating housesare sometimes built with permanent propagating-frames of this character throughout their length.

Fig. 33. Simple Propagating-oven.

Fig. 34. Propagating-oven.

In all the above appliances heat is obtained from the sun or from the bench-pipes or flues of a greenhouse. There are various contrivances in which the heat is applied locally, for the purpose of securing greater or more uniform heat. One of the simplest and best of these is the propagating-oven shown inFig. 33. It is a glass covered box about two feet deep, with a tray of water beneath the soil, and which is heated by a lamp. A similar but somewhat complicated apparatus is illustrated in Figs.34,35,36. This is an old form of oven, which has been variously modified by different operators.Fig. 34shows a sectional view of the complete apparatus. The box, A A, is made of wood and is usually about three feet square. L is a removable glass top. B represents a zinc or galvanized iron tray which is filled with earth in which seeds are sown or pots are plunged. C is a water tray to which the water is applied by means of a funnel extending through the box. A lamp, D,supplies the heat. A funnel of tin,e e, distributes the heat evenly. Holes should be provided about the bottom of the box to admit air to the flame. A modified form of this device is shown in Figs.35and36. The water tray, G, slides in upon ledges so that it can be removed, and the heat funnel, L D L, slides in similarly and is made to surround the flame like a chimney. The front side of the apparatus is removable, and the top of the frame, K, is made of metal. The cover for this apparatus is figured inFig. 36. The ends,a a, are made of wood, with openings, indicated by the arrows, to allow of ventilation. The front and top,g g, are made of glass. The frame-work,c c c, is made of metal. The cover is hinged on, or held with pegs, I I,Fig. 35.

Fig. 35. Modified form ofFig. 34.

Fig. 36. Cover forFig. 35.

Chauvière’s propagating-frame, an apparatus used by the French, is shown inFig. 37. It is essentially a miniature greenhouse. The sashes are seen atc c, and above them is a cloth or matting screen. The sides below the sashes are enclosed, preferably with glass. The bottom or floor is moveable, and it is sometimes divided into two or three sections to allow for the accommodation of plants of different sizes and requirements. These sections are raised or lowered and are held by pegs. At a is shown a section of floor elevated, and at the left another section occupying a lower position. Heat is supplied usually by hot water in the tubes,d d. A very elaborate circular French device, known as Lecoq’s propagating-oven, is illustrated inFig. 38. It is an interesting apparatus,and is worth attention as showing the care which has been taken to control the conditions of vegetation and germination. It is too elaborate for common purposes, and yet for the growing of certain rare or difficult subjects it might find favor among those who like to experiment; and it affords an accurate means of studying plant growth under control. The apparatus is sold in France for about $6. All the portion below the glass top,P p, is made of earthenware. The base,a a, holds a lamp,d;eis a water reservoir to which water is supplied by means of the funnel,j. A vase or rim,b b, rests upon the base, and upon it aplate or disc,c c, is fitted. Above this is a glass top,P p. Air is admitted to the apparatus ati,K K, and between the vase and plate, as atcon the right. The plate contains two circular grooves,g gandh h. In these grooves the soil is placed or pots plunged. The heat circulates in the valleysmandn n n n, and supplies a uniform temperature to both sides of the plants.

Fig. 37. Chauvière’s Propagating-oven.

Fig. 38. Lecoq’s Propagating-oven.

Fig. 39. Barnard’s Propagating-tank.

Barnard’s propagating-tank,Fig. 39, is a practicable device for attachment to a common stove. A similar apparatus may be attached to the pipes of a greenhouse. The tank consists of a long wooden box made of matched boards, and put together with paint between the joints to make the box water-tight. The box should be about three feet wide and ten inches deep, and may be from ten to thirty feet long, according to the space required. In the middle of the box is a partition, extending nearly the whole length of the box, and on the inside, on each side, is a ledge or piece of moulding to support slates to be laid over the entire surface of the box. The slates are supported by the ledges and by the central partition, and should be fastened down with cement to prevent the propagating sand from falling into the tank. One slate is left out near the end, next the fire, to enable the operator to see the water and to keep it at the right level. On the slates sand is spread, in which the cuttings may be struck, the sand nearly filling the box. At one end of the box is placed a common cylinder stove, with pipe to the chimney. Inside the stove is a lead or iron pipe (iron is the best) bent in a spiral. This coil, which is directly in the fire, is connectedby iron pipes with the tank, one pipe leading to one side of the partition and the other to the opposite side, as shown in the drawing. If water is placed in the tank it will fill the pipes and form a continuous circulating system through the pipes and up one side of the box past the end of the partition, and down the other side. A fire in the stove causes the water to circulate through the tank and impart to the bed a genial warmth.

Fig. 40. Zinc Propagating-tank.

There are various tanks designed to rest upon the pipes in a greenhouse. The principle of their construction is essentially the same as of those described in previous pages—bottom heat, a tray of water, and a bed of soil. Earthenware tanks are commonly employed, but a recent English device,Fig. 40, is made of zinc. It is about seven inches deep, and holds an inch or two of water in the bottom. A tray five inches deep sets into the tank. The water is supplied through a funnel at the base.

Cuttings usually “strike” better when they touch the side of the pot than when they are wholly surrounded by soil. This is because the earthenware allows greater uniformity in moisture than the earth, and supplies air and a mild bottom heat. Various devices are employed for the purpose of securing these advantages to the best effect. These are usually double pots, in one of which water is placed. A good method is that represented inFig. 41, which shows a pot,b, plugged with plaster of Paris at the bottom, placed inside a larger one. The earth is placed between the two, drainage material occupying the bottom,a, and fine soil the top,c. Water stands in the inner pot as high as the dotted line and feeds uniformly into the surrounding soil. The positions of the water and soil are frequently reversed, but in that case there is less space available for cuttings. Neumann’s cutting-pot is shown inFig. 42. This contains an inverted pot in the center,a, designed to supply drainage and to admit heat into the center of the mass of soil.

Fig. 41. Forsyth’s Cutting-pot.

Some kind of protection, commonly combined with bottom heat, is always given cuttings made from the soft and growing parts. In in-door work, any of the devices named above may be employed, but a box like that shown inFig. 32is one of the most useful for common operations. Or the greenhouse itself may afford sufficient protection, especially if the cuttings are shaded when first set to check evaporation from the plant and soil, and to prevent too great heat. This shading is usually supplied by whitewashing the glass, or a newspaper may be laid over the cutting bed for a few days. A greenhouse table or bench prepared for the growing of cuttings is known as a “cutting bench.” If the cuttings become too dry or too hot, they will wilt or “flag.” In out-door work soft cuttings are usually placed in an ordinary cold-frame, and these frames must be shaded. They may be placed under trees or on the shady side of a building, or if they are numerous, as in commercial establishments, a cloth screen should be provided as shown inFig. 5,page 13.

Fig. 42. Neumann’s Cutting-pot.

Soils and General Methods.—Soil for all cuttings should be well-drained. It should not be so compact as to hold a great quantity of water, nor should it be so loose as to dry out very quickly. It should not “bake” or form a crust on its surface. As a rule, especially for cuttings made of growing parts, the soil shouldnot contain vegetable matter, as such material holds too much water and it is often directly injurious to the cutting. A coarse sharp, clean sand is the best material for use in-doors. Very fine sand packs too hard, and should not be used. Some propagators prefer to use fine gravel, composed of particles from an eighth to a fourth of an inch in diameter, and from which all fine material has been washed. This answers well for green cuttings if a propagating-frame is used to check evaporation and attention is given to watering, because drainage is so perfect and the material so quickly permeable that uniformity of treatment is secured. Damping-off is less liable to occur in such material than in denser soils. The same advantages are to some extent present in sphagnum moss and cocoanut fibre, both of which are sometimes used in place of earth. The “silver sand” used by florists is a very clean and white sand which derives its particular advantages from the almost entire absence of any vegetable matter. But it is not now considered so essential to successful propagation as it was formerly, and fully as good material may often be found in a common sand-bank. Cuttings which strike strongly and vigorously may be placed in a soil made of light garden loam with twice its bulk of sand added to it. All soils used for in-door cuttage should be sifted or screened before using to bring them to a uniform texture.

Hard-wood cuttings are commonly planted out-doors in mellow and light loam, well trenched. Only fine and well-rotted manure should be applied to the cutting bed, and it should be well mixed with the soil. In most cases, a well-drained soil gives best results, but some cuttings root and grow well in wet soils or even in standing water, as poplars, willows, some of the dogwoods, plane-tree and others.

Bottom heat is always essential to the best success with cuttings. In out-door work this is supplied by the natural heat of the soil in spring and summer, and it is often intensified by burying hard-wooded cuttings bottom end up for a time before planting them. This operation of inverting cuttings is often practiced with grapes, particularly with the Delaware and others which root with some difficulty. The cuttings are tied inbundles and are buried in a sandy place, with the tops down, the butts being covered two or three inches with sand. They may be put in this position in the fall and allowed to remain until the ground begins to freeze hard, or they may be buried in spring and allowed to remain until May or June and then be regularly planted. In out-door cuttage, the cuttings which are of medium length, from six to eight inches, derive more bottom heat than the very long ones, such as were formerly used for the propagation of the grape. In in-door work bottom heat is obtained artificially. Cutting benches should have abundant piping beneath, and in the case of many tropical and sub-tropical species the bottom heat may be intensified by enclosing the benches below so that no heat can escape into the house. Doors can be placed in the partition alongside the walk to serve as ventilators if the heat should become too intense. In all cuttings, bottom or root growth should precede top growth, and this is aided by bottom heat.

Fig. 43. Grape cutting.

As a rule, roots arise most readily from a joint, and it is therefore a common practice to cut off the base of the cutting just below a bud, as shown in the grape cutting,Fig. 43. Sometimes the cutting is severed at its point of attachment to the parent branch, and a small portion, or “heel,” of that branch is allowed to remain on the cutting. This heel may be nothing more than the curved and hardened base of the cutting at its point of attachment, as in the cornus cutting,Fig. 44. Sometimes an entire section of the parent branch is removed with the cutting, as in the “mallet” cuttings of grapes,Fig. 45. Of course, comparatively few heel or mallet cuttings can be made from a plant, as only one cutting is obtained from a branch, and it is advisable, therefore, to “cut to buds” rather than “cut to heels;” yet there are many plants which demand a heel, if satisfactory results are to be obtained. The requirements of the different species in thisdirection can be learned only by experience, but it may be said that in general the hardest or closest wooded plants require a heel or a joint at the base. Willows, currants, basswoods, and others with like soft wood, emit roots readily between the buds, yet even in these cases propagators quite usually cut to buds.

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