Forsythia(Golden Bell).Oleaceæ.
Propagated extensively by green cuttings in summer, in a frame; also grown from ripe cuttings taken in fall and winter, and planted in the open air in early spring.
Fothergilla.Hamamelideæ.
Propagated by seeds, sown in spring in a peaty soil; by layers.
Four-o’clock.SeeMirabilis.
Foxglove.SeeDigitalis.
Fragaria.SeeStrawberry.
Franciscea.SeeBrunfelsia.
Francoa.Saxifrageæ.
Seeds, sown in early spring in a cool frame. Also by division.
Frangula.SeeRhamnus.
Frankenia, including Beatsonia, Hypericopsis.Frankeniaceæ.
Increased by seeds and divisions.
Fraxinella.SeeDictamnus.
Fraxinus(Ash).Oleaceæ.
Propagated chiefly by seeds, which should be stratified. The named sorts are budded upon seedling stocks if the sorts are upright growers, or top-grafted if they are weepers. Both the European and American species are used for stocks.
Freesia.Irideæ.
Increased readily by seed, sown as soon as ripe in pots of light, sandy soil, and placed in a sunny position, in a cool frame. By bulbels.
Fremontia.Malvaceæ.
Seeds may be used; or cuttings, in spring, may be struck under a hand-glass.
French Bean(Varieties ofPhaseolus vulgarisandP. nanus).Leguminosæ.
Propagated by seeds.
Freycinetia.Pandaneæ.
Increased by offsets.
Fringe-tree.SeeChionanthus.
Fritillaria.Liliaceæ.
Seeds, sown as soon as ripe where the plants are to stand the first year. Bulbels and division.
Fuchsia(Ladies' Ear Drop).Onagrariæ.
Fuchsias grow readily from seeds, which should be sown as soon as ripe, and blooming plants ought to be obtained in eight or ten months. Cuttings of the young growth strike quickly and easily. Blooming plants of most sorts can be obtained in four or five months.
Fumaria(Fumitory).Papaveraceæ.
Propagated by seeds.
Funkia, Hosta (Plantain Lily, White Day Lily).Liliaceæ.
Propagation is effected by dividing the stools during the early autumn, or when they begin to start in spring. Only strong, healthy clumps should be divided, and each portion should contain several crowns.
Furze.SeeUlex.
Gaillardia.Compositæ.
The annual sorts are propagated by seeds started under glass; the perennial kinds by seeds, cuttings or division. Sometimes root-cuttings are used.
Galanthus(Snowdrop).Amaryllideæ.
Commonly by bulbels. Rarely by seeds.
Galax, Erythrorhiza, Solonandra.Diapensiaceæ.
Propagated by divisions of strong clumps in autumn.
Galega(Goat’s Rue).Leguminosæ.
Seeds, in spring; also by division.
Galtonia.Liliaceæ.
Increased by bulbels or seeds.
Garcinia, Cambogia, Mangostana, Oxycarpus.Guttiferæ.
Seeds. Cuttings of ripened shoots should be inserted in sand under a glass, in strong bottom heat.
Gardenia, including Rothmannia.Rubiaceæ.
Strong, healthy cuttings may be taken with a heel, early in the year being the best time, but any season will do when suitable cuttings can be secured. They should be placed in bottom heat of about 75°, in a frame.
Garlic(Allium sativum).Liliaceæ.
By “cloves” or divisions of the bulb. In the north these are planted in the spring, but in warm climates they may be planted in the fall.
Garrya, including Fadyenia.Cornaceæ.
Propagated by seeds, or by cuttings of half-ripened wood in sandy loam in August, and shaded until rooted. Also by budding onAucuba Japonicaat the crown. Plant sufficiently deep to cover the bud or graft.
Gasteria.SeeAloe.
Gaultheria(Boyberry, Wintergreen).Ericaceæ.
Increased by seeds, divisions, layers and cuttings under glass.
Gaura.Onagrarieæ.
Seeds should be sown in spring or fall in the open ground.
Gaylussacia.SeeVaccinium.
Gazania, Mœhnia, Mussinia.Compositæ.
Increased by seeds and divisions. Make cuttings in July or August, from the side shoots near the base of the plant; these should be placed in a sandy soil, in a frame.
Gelsemium, Leptopteris, Medicia.Loganiaceæ.
Propagated by cuttings under glass.
Genista.SeeCytisus.
Gentiana(Gentian).Gentianeæ.
Seeds and division. The seeds germinate slowly, and often with difficulty. They often lie dormant a year or more. They should be sown in well-sifted light loam, in pans or flats, and kept cool and shaded. Division must be carefully done, or the plants will suffer.
Geonoma.Palmæ.
Increased by seeds and suckers.
Geranium.Geraniaceæ.
Mostly by seeds and divisions. For the conservatory plants known as geraniums, see Pelargonium.
Gerardia.Scrophularineæ.
Propagated, but often with difficulty, by seeds, sown in the open air or in a frame or cool house.
Gesnera.Gesneraceæ.
Seeds, and cuttings of the shoots and leaves. Handled in essentially the same manner as Gloxinia, which see.
Gethyllis.Amaryllideæ.
They may be increased by bulbels or seeds.
Geum, including Sieversia (Avens).Rosaceæ.
Gherkin.SeeCucumber.
Propagation is effected by seeds or division.
Gilia, including Fenzlia.Polemoniaceæ.
Seeds should be sown in spring in the open ground or frame, in a rather light soil.
Gilibertia.Araliaceæ.
Cuttings, inserted in sand in a gentle heat.
Gillenia.Rosaceæ.
Increased readily by dividing the roots in spring; also by seeds.
Gilliesia.Liliaceæ.
Propagated by bulbels.
Gilliflower.SeeMatthiola.
Ginkgo, Salisburia (Maidenhair-tree).Coniferæ.
Seeds, which are mostly imported, and which should be stratified. Also by layers, and by cuttings of either green or ripe wood. The cuttings are handled under glass. Named varieties are grafted upon common stocks.
Ginseng.SeeAralia.
Gladiolus.Irideæ.
Seeds, which are commonly sown in pans in spring, in the house; or they may be sown in the border. Seedlings flower in two or three years. The common method of propagation is by means of cormels (seepage 29, andFig. 16). These are removed from the parent corm and planted in the open, where some of them will flower the same season, although most of them will require a season’s independent growth before they flower. If cormels are desired in abundance, the large corms should not be allowed to flower. Some varietiesdo not produce cormels readily, and these may be made to bear them by cutting or ringing (page 30). A new corm is formed above the old one each year (Fig. 16).
Glastonbury-thorn.SeeCratægus.
Gleditschia.Leguminosæ.
Seeds should be sown in spring about one inch deep. They should be soaked in hot water before being sown. Varieties propagated by grafts upon seedling stock.
Gleichenia.SeeFerns.
Globe Flower.SeeTrollius.
Globularia.Selagineæ.
Propagated by seeds, division or cuttings.
Gloriosa, Clynostylis, Methonica.Liliaceæ.
Seeds should be inserted singly in small pots, in a light sandy soil, and plunged in bottom heat. Bulbels, which should be carefully removed from the old bulbs when starting them in spring, as the roots are very brittle.
Gloxinia, Escheria, Salisia.Gesneraceæ.
Seeds should be sown the latter part of winter, in well-drained pots or small pans of finely sifted soil, of peat, leaf-mould and sand in about equal proportions. The seeds should be sown thinly and covered slightly, then carefully watered, and placed in a temperature of about 70° and kept shaded. Cuttings of the shoots may be taken when the old tubers are starting in spring, and placed in a close propagating frame. Leaf-cuttings, with a small portion of the petiole attached, give excellent results, especially when the leaves are firm and nearly matured. Leaf cuttings are made in the various ways in which begonia leaf-cuttings are made (see pp. 60-72, Figs.59,60). Also grafted (seepage 88).
Glycine.SeeWistaria.
Glycosmis.Rutaceæ.
Seeds. Increased by cuttings, which are commonly inserted in sand under glass, often in heat.
Glycyrrhiza, including Liquiritia (Liquorice).Leguminosæ.
Propagated by division and by seeds.
Godetia.See Œnothera.
Golden Rod.SeeSolidago.
Goldfussia.SeeStrobilanthes.
Gomphia(Button Flower).Ochnaceæ.
Cuttings of firm young shoots should be placed in sand under glass, in heat.
Gomphocarpus.Asclepiadeæ.
Seeds should be sown under glass in spring; or cuttings may be made of small side shoots when the plant is commencing new growth, and placed in sand under glass.
Gompholobium.Leguminosæ.
Cuttings, which should be made of young shoots during spring, and placed under glass.
Gomphrena.SeeCelosia.
Gonolobus.Asclepiadeæ.
Seeds, divisions, and cuttings under glass.
Goodenia.Goodenovieæ.
Seed. During spring, cuttings will root freely if placed under glass.
Goodia.Leguminosæ.
Seeds may be used. Cuttings of young shoots may be made during spring, and placed in a frame.
Gooseberry(Ribes GrossulariaandR. oxyacanthoides).Saxifrageæ.
Seeds, for the raising of new varieties, should be sown as soon as well cured, in loamy or sandy soil, or they may be stratified and sown together with the sand in the spring. Cuttings six to eight inches long of the mature wood, inserted two-thirds their length, usually grow readily, especially if taken in August or September and stored during winter, in the same way as currant cuttings. Single eye cuttings may be used for rare kinds. Stronger plants are usually obtained by layers, and the English varieties are nearly always layered in this country. Mound-layering is usually employed, the English varieties being allowed to remain in layerage two years, but the American varieties only one (Fig. 21). Layered plants are usually set in nursery rows for a year after removal from the stools. Green-layering during summer is sometimes practiced for new or rare varieties. Strong plants may also be procured by tip-layering, as in the black raspberry (see p. 33). If it is desired to train the weaker gooseberries in tree form, they may be grafted upon the stronger-growing varieties.
Gordonia, including Polyspora.Ternstrœmiaceæ.
Propagated by seeds or layers.
Gorse.SeeUlex.
Goumi.SeeElæagnus.
Gourds(Cucurbita Pepo,Lagenaria, etc.).Cucurbitaceæ.
Seeds, after the weather is settled and ground is warm.
Grammanthes.Crassulaceæ.
Seeds, sown in spring in a warm house.
Granadilla(Passiflora edulis, etc.).Passifloreæ.
Propagated by seeds, or, less easily, by cuttings.
Grape(Vitis, several species).Vitaceæ.
Grape seedlings are very easily grown. If the ground is fit and there is no danger from vermin, the seeds may be sown in the fall, but they are usually stratified and sown in spring. They come readily if sown out-doors, but some prefer to force them under glass with a mild bottom heat. Seedlings do not “come true,” and they are therefore grown only for the purpose of obtaining new sorts.
The grape is very readily multiplied by layers, either of the ripe or green-wood. The ripe wood or canes may be layered either in fall or spring, but spring is usually chosen. The cane is simply covered up two or three inches deep, and nearly every bud will produce a plant. In August or September the layer should be lifted and cut up into plants. Better plants are obtained if only the strongest canes are used and only a part of the buds on each are allowed to grow. The cane is usually cut back to four or five buds, or if very strong plants are desired only one bud is left on each layer. Canes of the previous year, those recently matured, are preferred, although wood two or three years old may be used, but in this case it is usually necessary to cut or otherwise wound the joint in order to induce the formation of roots. Vines or stools grown for the production of layers should be cut back severely in fall or winter, to induce a vigorous growth of canes the following season. These canes are then layered the succeeding fall or spring. Only a part of the canes are layered from any stool, a part being allowed to grow for cutting back the next fall in order to get another crop of canes. In some varieties which do not strike readily from cuttings, layering is considerably practiced by nurserymen. The Delaware is often grown in this way. Extra strong layers can be secured by layering in pots. A largepot, filled with rich soil, is plunged beneath the layer. In this manner a layer may be rooted and separated even while carrying fruit. Layering in pots is employed only in special cases.
Green-layering is sometimes practiced upon new and scarce varieties, but strong plants are not obtained unless they are well handled by forceful culture after they are separated. The growing cane is layered in mid-summer, usually by serpentine layering.
Cuttings are usually employed by nurserymen to propagate the grape. These are made in many fashions. In all ordinary cases hard-wood cuttings are made from the ripened canes in autumn or winter when the vines are pruned. It is advisable to take the cuttings before the canes have been exposed to great cold. Select only those canes which are well-matured, solid and rather short-jointed. In common practice, the cuttings are cut into two-bud length, the lower cut being made close to the bud. The cuttings will range from six to ten inches in length. Some prefer three-bud cuttings (Fig. 43), but unless the cane is very short-jointed such cuttings are too long to be planted and handled economically. Three-bud cuttings usually give stronger plants the first season because roots start from both joints as a rule. Very strong plants are obtained from mallet cuttings (Fig. 45), but as only one such cutting can be made from a cane, unless the cane bears very strong branches, they are not much used. Various methods of peeling, slitting and slicing cuttings are recommended, in order to extend the callusing process but they are not used in common or commercial practice. The cuttings are tied in bundles of 50 or 100, and stored in sand, moss, or sawdust in a cellar, until spring, when they are planted in rows in the open. Some varieties, of which the Delaware is an example, do not strike readily from cuttings. Some growers start common cuttings of these under glass in spring. Others bury the bundles of cuttings in a warm exposure in the fall, with the butt ends up and about level with the surface of the ground. This affords bottom heat to the butts and induces callusing. At the approach of cold weather the cuttings are removed to a cellar, or are heavily mulched and allowed to remain where buried. Storing is safer. Some growers obtain the same results by burying upside down in a cellar. These slow-rooting sorts often start well if they are simply kept in a warm cellar—but where the buds will not swell—all winter, as the callusing is then hastened. At the end of the first season the plants may be transplanted. The plants areoften sold at this age, but buyers usually prefer two-year-old plants.
Single bud or “eye” cuttings are largely used for the newer and rarer varieties. These are cut from the canes in the fall, the same as long cuttings, and are stored in boxes of sand or moss. A month before the weather becomes settled, these boxes may be taken into a house or greenhouse, or put in a mild hot-bed, to induce the formation of the callus. They may then be planted out-doors, and a fair proportion of most varieties may be expected to grow. The best and commonest way of handling eyes, however, is to start them under glass. They are planted horizontally or nearly so and about an inch deep in sand or sandy earth in a cool greenhouse in late winter—in February in the northern states—and in about six weeks the plants will be large enough to pot off or to transplant into cold-frames or a cool house. If only a few plants are to be grown they may be started in pots. When the weather is thoroughly settled, they are transferred to nursery rows, and by fall they will make fine plants. There are various ways recommended for the cutting of these eyes—as cutting the ends obliquely up or down, shaving off the bark below the bud, and so on—but the advantages of these fashions are imaginary. A good eye-cutting is shown inFig. 50. The foreign grapes are propagated by eyes in the north.
Soft cuttings are sometimes used to multiply new kinds. These may be taken in summer from the growing canes, but the plants are usually forced during winter for the purpose of giving extra wood. Cuttings are taken off as fast as buds form during the winter, and they are forced in close frames with a good bottom heat. The cuttings may comprise two buds, with the leaf at the upper one allowed to remain, or they may bear but a single eye, in which case the leaf, or the most of it, is left on. This rapid multiplication from small, soft wood usually gives poor plants; but strong plants may be obtained by allowing the wood to become well hardened before it is used. Soft cuttings will root in two or three weeks under good treatment.
In order to secure extra strong plants from single buds, the eyes may be saddle-grafted or whip-grafted upon a root two or three inches long. The root-grafts are then treated in the same way as eye cuttings, only that they are usually grown in pots from the start.
The vine may be grafted with ease by any method. Cleft-grafting is commonly employed upon old plants. The cions are inserted on the crown of the plant, three or four inchesbelow the surface of the ground. The cleft is bound with string and then covered with earth, no wax being necessary. Young plants are usually whip-grafted at the crown, either in-doors or out-doors. Grafting the vine is mostly confined to Europe, California, and other countries where the European grape (Vitis vinifera) is grown, as that species must be grafted upon some other stock in order to resist the phylloxera. The common wild frost-grape (Vitis riparia) is the most popular stock. The union in these cases must be two or three inches above the ground, to prevent the cion from taking root. The union is wound with waxed muslin, and the earth is heaped about it until it has healed. Grafting may be done out-doors in winter or spring. In the north, winter grafts are likely to be heaved by frosts, and late spring grafts, made as the leaves are pushing, are probably best.
The vine is frequently inarched, and early in spring it can be budded by ordinary methods.
Seed-grafting is a curious practice, which may be applied to the grape (seepage 90).
Grape Hyacinth.SeeMuscari.
Graptophyllum, Earlia.Acanthaceæ.
Seeds. Increased by cuttings of rather firm young shoots placed in a frame with some heat.
Gratiola, Sophronanthe (Hedge Hyssop).Scrophularineæ.
Seeds. Propagated readily by dividing the roots in spring.
Grevillea.Proteaceæ.
Propagated by seeds, sown under glass in February; also by cuttings of half-ripened wood.
Grewia, Chadara, Mallococca.Tiliaceæ.
Seeds. Cuttings may be struck in sand under glass, with heat.
Grindelia.Compositæ.
Seeds, sown in the border or under a frame. Divisions. Cuttings.
Ground-Cherry.SeePhysalis.
Ground-Nut.SeeApios; also Pea-nut.
Groundsel.SeeSenecio.
Guaiacum.Zygophylleæ.
Ripened cuttings in spring, under a hand-glass, in heat.
Guava(Psidium, several species).Myrtaceæ.
The guavas grow readily from seeds, and plants will often bloom when a year and a half old. They may also be multiplied by layers, and by cuttings either under glass or in the open.
Guelder Rose.SeeViburnum.
Guernsey Lily.SeeNerine.
Gumbo.SeeHibiscus.
Gum, Sweet.SeeLiquidambar.
Gum-tree.SeeEucalyptus.
Gunnera.Halorageæ.
Propagated by division. It is very difficult to raise from seed.
Gustavia, Pirigara.Myrtaceæ.
Cuttings, made of ripened shoots and handled in a frame.
Gymnema.Asclepiadeæ.
Make cuttings of firm side shoots in spring, and place in a frame.
Gymnocladus(Kentucky Coffee-tree).Leguminosæ.
Readily increased by seeds, which start better if soaked for a few hours in hot water. Also by root-cuttings.
Gymnogramme.SeeFerns.
Gymnyostachys.Aroideæ.
Propagation is effected by suckers and divisions.
Gynerium(Pampas Grass).Gramineæ.
Seeds, under glass in the north. Also increased by dividing the tufts.
Gynura.Compositæ.
Increased by cuttings and seeds.
Gypsophila.Caryophylleæ.
Propagated by seeds, division or cuttings.
Habranthus.SeeZephyranthes.
Habrothamnus.SeeCestrum.
Hackberry.SeeCeltis.
Hæmanthus(Blood Flower).Amaryllideæ.
Bulbels, which should be removed and potted when the plants are commencing new growth, and be kept in a close pit or house till established. Seeds are rarely used.
Hæmodorum(Australian Blood-root).Hæmodoraceæ.
Increased by dividing the roots in spring.
Hakea, Conchium.Proteaceæ.
Well-ripened cuttings, placed in sandy peat under glass, in a cool house. Seeds, when obtainable, can be used.
Halesia, Pterostyrax (Silver-bell or Snowdrop Tree).Styracaceæ.
Seeds, which rarely germinate till the second year. They should be kept constantly moist. Propagation is also effected by layers, or by cuttings of the roots in spring and autumn. Layers are commonly employed in this country.
Halimodendron(Salt-tree).Leguminosæ.
Freely increased by seeds, layers or cuttings. May also be grafted on common laburnum.
Hamamelis(Witch-hazel).Hamamelideæ.
All grow from seeds or layers, and the Japan species succeed if grafted on American species in the greenhouse.H. Virginicamay be readily propagated by layers.
Hamelia.Rubiaceæ.
Seeds. Cuttings which are nearly ripe will root during the early part of summer under glass, with heat.
Hamiltonia, Spermadictyon.Rubiaceæ.
Seeds. Half-ripened cuttings, placed in sand under glass.
Hardenbergia.Leguminosæ.
Seeds may be used; also increased by divisions. Cuttings, made of the firm young side shoots in spring, will grow if inserted under a bell-glass, and placed in a warm frame or pit, without bottom heat.
Hardwickia.Leguminosæ.
Propagated by ripened cuttings in sand, in a strong heat.
Harebell.SeeCampanula.
Hatchet Cactus.SeePelecyphora.
Haw, Hawthorn. SeeCratægus.
Hazel.SeeCorylus.
Heartsease.SeeViola.
Heath.SeeErica.
Heather.SeeCalluna.
Hedera(Ivy).Araliaceæ.
Seeds. Layers. The rooted portions of the vine may be severed and treated as independent plants. Cuttings may be made in autumn from any firm shoots, and inserted in pots or in the open ground. If they are placed in heat and kept shaded until roots are formed, good plants are obtained much sooner than when placed in a cold-frame or in the open air. Named varieties are grafted on the stock of any common strong climbing form.
Hedychium(Indian Garland Flower).Scitamineæ.
Seeds, rarely. Increased by dividing the rhizomes in spring, when the plants are repotted.
Hedysarum.Leguminosæ.
Propagation is effected by means of seeds and division.
Helenium.Compositæ.
Increased by seeds or divisions.
Helianthemum, including Fumana (Rock-Rose, Sun-Rose).Cistineæ.
The annuals are raised from seeds. The perennials may also be raised from seeds, but it is better to trust to layers and to cuttings, which will root freely in a sandy soil, if kept shaded until established.
Helianthus, including Harpalium (Sunflower).Compositæ.
By seeds, which may be sown in pots, and the seedlings transferred, or in the open ground in spring. Also divisions.
Helichrysum, Elichrysum (Everlastings).Compositæ.
The annual species and the varieties of H. bracteatum may be raised from seed, sown in a light heat in early spring, and afterwards transplanted; or sown in the open ground a little later. The perennial species are increased by cuttings in spring, in a close frame without heat.
Heliconia.Scitamineæ.
May be increased by seeds, but the best method is by division of the root stock in spring when growth commences. Separate pieces may be placed in pots, and grown in a moist stove temperature, repotting when necessary; or they may be planted out in the stove, if desired.
Heliotropium(Heliotrope).Boragineæ.
Seeds. The common practice is to use cuttings. These can be taken at almost any season, if good growing shootsare to be had. They start readily in sand or soil on a cutting bench, or under a frame. Plants for bedding are struck in late winter from stocks which are in a vigorous condition.
Helipterum, including Astelma, Rhodanthe.Compositæ.
Seeds may be sown in early spring, under cover.
Helleborus(Black Hellebore, Christmas Rose).Ranunculaceæ.
Seeds may be sown as soon as ripe. Strong and healthy root divisions are also employed.
Helonias.Liliaceæ.
Propagation is effected by seeds, and slowly by root divisions.
Hemerocallis(Day Lily).Liliaceæ.
Increased by divisions.H. Middendorfiiand some others by seed.
Hemlock Spruce.SeeTsuga.
Hemp.SeeCannabis.
Hepatica.Ranunculaceæ.
Can be propagated by division; also by seeds.
Heracleum(Cow Parsley, Cow Parsnip).Umbelliferæ.
Readily increased by seeds or divisions.
Herbertia.Irideæ.
Propagated by means of seeds or bulbels.
Herb-Robert.SeeGeranium.
Hesperis(Dame’s Violet, Rocket).Cruciferæ.
The single sorts are increased by seeds; the double forms by carefully dividing the roots, or by cuttings.
Heterocentron.Melastomaceæ.
Propagated by cuttings.
Heuchera(Alum Root).Saxifrageæ.
Seeds. Readily increased by dividing the crowns during spring.
Hevea, Micrandra, Siphonia.Euphorbiaceæ.
Cuttings should be made of half-ripened wood, and inserted in sand under glass.
Hibbertia, including Cyclandra, Pleurandra.Dilleniaceæ.
Cuttings, in sandy peat under glass.
Hibiscus.Malvaceæ.
Seeds sometimes. Also by divisions and layers. Cuttings of green-wood are commonly used, made in summer for hardy species or in early spring for tender ones. Cuttings of ripened wood may be taken in fall, and stored until spring in a rather dry place. The variegated sorts do better if grafted upon strong stocks.
Hicoria, Carya (Hickory, Pecan, etc.).Juglandeæ.
Increased chiefly by seeds, which should be stratified; also by root-sprouts. Seeds are sometimes planted at intervals in the field where the trees are to stand; but this practice is not to be recommended. The hickory can be grafted. Best results are obtained by veneer or splice-grafting in winter, on potted stocks. Cleft-grafting can be employed out-doors. Saddle-grafting upon young twigs is sometimes used. See also Pecan.
Hippeastrum(Equestrian Star).Amaryllideæ.
Seeds may be sown as soon as ripe in well-drained pots or pans of sandy loam, slightly covered, and placed in a temperature of about 65°. For increasing by divisions—which is the usual way—the old bulbs should be taken from the pots and carefully separated, with the least possible injury to the roots. This should be done when the plants are at rest, and the offsets should be placed singly in pots. Keep the bulb about two-thirds above the level of the soil, dispose the roots evenly, and plunge in bottom heat, in a position exposed to the light.
Hippomane, Mancinella.Euphorbiaceæ.
Propagated by cuttings, placed in sand under glass.
Hippophaë(Sallow Thorn, Sea Buckthorn).Elæagnaceæ.
May be increased by seeds, suckers, layers, and cuttings of the roots.
Hoffmannia, Higginsia.Rubiaceæ.
Insert cuttings in sandy soil under cover, in bottom heat.
Hog Plum.SeeSpondias.
Holbœllia.Berberideæ.
In spring, cuttings may be made of half-ripened shoots.
Holly.SeeIlex.
Hollyhock(Althæa).Malvaceæ.
Seeds should be sown as soon as ripe—in summer—in pots or pans, and placed in a slight bottom heat or in the openair. In either case, place the seedlings in 3-inch pots, and winter in a cold-frame. Dividing the roots, after flowering is over, by separating the crown, so as to preserve one or more buds and as many roots as possible to each piece. Cuttings of young shoots three inches long, taken off close to the old root at nearly the same time, should be placed singly in small pots of light, sandy soil and kept close, and shaded in a cold-frame until rooted. If cuttings are made during winter, a gentle bottom heat must be given. Also grafted (see page 88). See alsoAlthæa.
Honesty.SeeLunaria.
Honey-Locust.SeeGleditschia.
Honeysuckle.SeeLonicera.
Hop.SeeHumulus.
Hop Hornbeam.SeeOstrya.
Horehound(Marrubium vulgare).Labiatæ.
Seeds, in early spring. Division.
Horkelia.SeePotentilla.
Hornbeam.SeeCarpinus.
Horse Chestnut.SeeÆsculus.
Horse Mint.SeeMonarda.
Horse-Radish(Nasturtium Armoracia).Cruciferæ.
Root-cuttings (“sets”). These are made from the small side roots when the horse-radish is dug. They may be anywhere from one-fourth to one inch in diameter, and three to six inches long, one end being cut slanting, to mark it. These are planted obliquely, two to four inches deep, in spring. They may be buried during winter. (Fig. 48). The old crowns may be planted, but they make poorer roots.
Hottonia.Primulaceæ.
Propagation is effected by seeds and divisions in spring.
House-Leek.SeeSempervivum.
Houstonia.Rubiaceæ.
Seeds. May also be increased by carefully made divisions in autumn or spring.
Hovea, Poiretia.Leguminosæ.
Propagation is best effected by seeds, sown in well-drained pots of sandy peat soil in spring, and placed in a gentle bottom heat. Cuttings are difficult to strike.
Hovenia.Rhamneæ.
Increased by seeds. Root-cuttings are also used. Ripened cuttings should be placed in sand, under a hand-glass.
Hoya(Honey Plant, Wax Flower).Asclepiadeæ.
For layering, good-sized shoots should have a few of their leaves removed, and should then be put in pots of soil until rooted. The plants may afterwards be grown on, and repotted according to their strength. Cuttings may be taken in spring or later in the year, from shoots of the preceding summer’s growth, and placed in a compost of peat and sand, and plunged in bottom heat in a frame. A slight shade and careful watering will be necessary.H. belladoes best when grafted on a stronger growing sort.
Huckleberry.SeeVaccinium.
Humea, Agathomeris, Calomeria.Compositæ.
Sow seeds in light, finely sifted soil, and place in a frame in early summer.
Humulus(Hop).Urticaceæ.
It may be propagated by seeds, or by divisions in spring. Ordinarily, however, the species is increased by hard-wood cuttings of two-bud lengths from the best old shoots, and made in spring. Leave the top bud just above the ground.
Hyacinthus(Hyacinth).Liliaceæ.
Seeds are employed for the production of new varieties. These are sown the same season they mature, in light, sandy soil, and are covered not more than a half-inch deep. In four or five years, or sometimes even longer, the bulbs will be large enough to flower. Varieties are perpetuated by means of the bulbels which form freely upon some varieties. These are treated in much the same manner as mature bulbs, or they may be handled in pans or flats. They make flower bulbs in two or three years. To increase the numbers of these bulbels, the bulbs are variously cut by the Dutch growers. These practices are described and illustrated on pages 27 and 28, Figs.12-14. Hyacinths can be propagated by leaf cuttings. Strong leaves should be taken in early spring and cut into two or three portions, each portion being inserted about an inch in good sandy loam, and given a temperature of about 75°. In eight or ten weeks a bulblet will form at the base of the cutting (seepage 52). The lower leaves give better results than the upper ones. These bulblets are then treated in the same manner as bulbels.
Hydrangea, Hortensia.Saxifrageæ.
The hardy species are usually propagated by green cuttings in summer, under glass (seeFig. 57). The tender species are increased by cuttings taken at any time from vigorous young wood, usually in late winter. Layers are occasionally employed, and suckers can be separated from some species. Sometimes the hardy species are forced for purposes of propagation by cuttage.H. quercifoliais propagated by little suckers or “root pips.”H. paniculata, grandifloracan easily be propagated from the young wood, taken in June and planted under glass.
Hymenocallis.Amaryllideæ.
Treated the same as Pancratium, which see.
Hypericum, including Androsæmum.Hypericineæ.
Easily increased by seeds, cuttings, or by strong pieces of the roots of creeping-rooted species. Hard-wooded cuttings taken in fall, are commonly used.
Hypoxis.Amaryllideæ.
Propagation is effected by seeds and offsets.
Hyssop(Hyssopus officinalis).Labiatæ.
Seeds. Division.
Iberis(Candytuft).Cruciferæ.
The annuals and biennials are increased by seeds sown in light sandy soil, in spring or autumn. The sub-shrubby sorts are also increased by seeds sown in spring, but more often by divisions or by cuttings.
Idesia.Bixineæ.
Seeds may be sown in spring in gentle heat. Half-ripened cuttings may be made in spring or autumn, and should be inserted in sandy loam, and placed under a bell-glass, in gentle heat. Also by root-cuttings.
Ilex, including Prinos (Holly).Ilicineæ.
Seeds, which should be stratified. They are often cleaned of the pulpy coat by maceration. The seeds rarely germinate until the second year. Varieties are perpetuated by graftage. The veneer-graft, upon potted plants, is usually employed, but other methods may be successful. Budding is sometimes performed.
Illicium(Aniseed-tree).Magnoliaceæ.
Seeds. Cuttings of young ripened shoots may be made during summer and should be placed in sandy soil, under a glass.
Imantophylium.Amaryllideæ.
Seeds. Usually increased by division or by means of bulbels.
Impatiens, Balsamina (Balsam).Geraniaceæ.
The common annuals may be raised from seeds, in spring, in any ordinary light soil. The stove and greenhouse species may be increased by seeds, or from cuttings, which root freely in a close frame.I. Sultanidoes best from seeds.
Indian Fig.SeeOpuntia.
Indian Shot.SeeCanna.
Indigofera(Indigo).Leguminosæ.
Propagated by seeds. Cuttings of young shoots may be inserted in sandy or peaty soil under glass, in slight heat.
Inga.Leguminosæ.
Propagated by seeds. Cuttings root with difficulty.
Inula, Elecampane.Compositæ.
Readily increased by seeds or by divisions.
Ionidium, Solea.Violarieæ.
The herbaceous species are increased by seeds and by divisions. The shrubby sorts are increased by cuttings which will root in sand, in a frame.
Ipomœa, including Quamoclit (Moon-flower, Morning Glory).Convolvulaceæ.
All the annual species are grown from seeds. The perennials are also increased by seedage, but they may be raised from cuttings struck in a forcing-house or a frame. The moon-flowers often do better in the north from cuttings than from seeds.I. Horsfalliæis largely propagated by layers, and other species may be treated in the same way. Division is sometimes employed.I. panduratacan be propagated by root-cuttings. Also grafted (seepage 88).
Ipomopsis.SeeGilia.
Iresine, Achyranthes.Amarantaceæ.
Seeds rarely. Increased readily by cuttings. For summer bedding in the north, cuttings should be started in February or March. For use as window plants, they should be taken in late summer.
Iriartea, Deckeria.Palmæ.
Propagation is effected by seeds.
Iris, including Xiphion.Irideæ.
Seeds grow readily and give good results, and they are usually produced freely, especially in the bulbous species. Sow as soon as ripe in light soil in some protected place. The bulbous species produce bulbels, which may be used for multiplication. The rhizomatous species are propagated by dividing the rhizome into short rooted pieces. Or when the rhizomes lie on the surface of the ground and do not root readily, they may be layered.
Isonandra(Gutta-Percha Tree).Sapotaceæ.
Insert cuttings in sandy soil, under glass, in heat.
Isoplexis, Callianassa.Scrophularineæ.
Cuttings of half-ripened shoots should be made in spring under glass.
Isopyram.Ranunculaceæ.
Propagated by seeds or by divisions, in autumn or spring.
Itea.Saxifrageæ.
Propagated by seeds or by suckers, in spring; and in autumn by layers.
Ivy.SeeHederaandAmpelopsis.
Ixia, including Morphixia.Irideæ.
Seeds may be sown in pans of sandy soil in autumn, and placed in a cool frame. Propagation by bulbels is a much quicker, as it is the usual method.
Ixiolirion, Kolpakowskia.Amaryllideæ.
Increased by seeds; and by bulbels.
Ixora.Rubiaceæ.
Seeds. Usually increased by short-jointed green cuttings placed in a close frame with a strong bottom heat.
Jaborosa.Solanaceæ.
Increased by seeds sown in spring, and by divisions, also by cuttings of young shoots, placed under a frame.
Jacaranda.Bignoniaceæ.
Cuttings of half-ripened shoots may be made in early summer and placed in sand over sandy peat, in heat, and kept shaded. Also seeds.
Jacobæan Lily.SeeAmaryllis.
Jacobinia.SeeJusticia.
Jacquinia.Myrsineæ.
Cuttings of ripened shoots, usually made in summer, placed in sand, in a moist bottom heat.
Jalapa.SeeMirabilis.
Jambosa.SeeMyrtus.
Jasione(Sheep’s Scabious).Campanulaceæ.
Seeds, sown in spring or fall, usually in the open. The perennials may be divided.
Jasminum(Jasmine, Jessamine).Oleaceæ.
Sometimes by seeds, but usually by cuttings of the nearly ripened wood, under glass. Cuttings of ripe wood are also employed, and layers are often used.
Jatropha.Euphorbiaceæ.
Cuttings made of firm young shoots will strike in sandy soil in a strong bottom heat. The cuttings, if very fleshy, may be dried a few days before setting them.
Jeffersonia.Berberideæ.
Seeds should be sown as soon as ripe, or divisions may be made.
Jerusalem Artichoke(Girasole). SeeArtichoke.
Jessamine, Yellow.SeeGelsemium.
Jonquil.SeeNarcissus.
Jubæa(Coquito Palm of Chili).Palmæ.
Propagation is effected by seeds.
Judas-tree.SeeCercis.
Juglans(Walnut and Butternut).Juglandeæ.
All the species are readily propagated by means of stratified nuts. Do not allow the nuts to become dry. Artificial cracking should not be done. In stiff soils the seedlings are apt to produce a long tap-root which renders transplanting difficult after the first year or two. The tap-root may be cut by a long knife while the tree is growing, or the young seedling may be transplanted. Particular varieties are perpetuated by grafting or budding with any of the common methods. In the north, they are sometimes worked indoors in pots. Common shield-budding works well, if the sap is flowing freely in the stock. Flute-budding is often employed. The improved native sorts are root-grafted in winter. Old trees can be top-grafted like apple-trees (seep. 90).
The “English” walnut (J. regia) is mostly grown direct from seed in this country, and the different varieties usually come true. In California, the native walnut (J. Californica) is often used as a stock for this species, and flute-budding on branches a half-inch or more in diameter is often practiced. “Twig-budding,” or the insertion of a short branchlet or bit of branch which is severed from the parent branch in the same manner as a shield bud, is sometimes employed.
Jujube(Zizyphus Jujube).Rhamneæ.
Seeds and cuttings.
Juncus(Rush, Bulrush).Junceæ.
Seeds. The perennials may be increased by division.
Juneberry(Amelanchier Canadensis, var.oblongifolia).Rosaceæ.
Increased by using the sprouts which form freely about the old plants; also by seeds.
Juniperus(Juniper, Red Cedar).Coniferæ.
Increased readily by seeds, which, however, often lie dormant until the second year. They germinate more readily if the pulp is removed by maceration or by soaking with ashes for a few days. Green cuttings, in sand under glass, root easily; or mature cuttings may be taken in fall and placed in a cold-frame, in which they will need little protection during winter. Some varieties require a long time to root. Most of the named varieties may be grafted on imported Irish stocks, which are much used in some parts of the country. They may be veneer-grafted and handled in a cool house.
Jurinea.Compositæ.
Increased in spring by seeds or by divisions.
Jussiæa.Onagrarieæ.
Seeds and divisions are used for propagating.
Justicia, including Jacobinia and Sericographis.Acanthaceæ.
Seeds occasionally. The species strike readily from short green cuttings on a cutting bench or under a frame.
Kadsura, Sarcocarpon.Magnoliaceæ.
Seeds. Cuttings, made of nearly ripened shoots, which should be placed in sand under glass.
Kaki.SeePersimmon.
Kalanchoe.Crassulaceæ.
Propagated by seeds, but cuttings, when obtainable, are better.
Kale(Brassica oleracea, vars.).Cruciferæ.
By seeds, sown in the open in spring in the north, or in the fall in the south.
Kalmia(Mountain Laurel, Calico-bush).Ericaceæ.
May be increased by seeds, which should be sown in shallow pans of sandy peat, and kept in a cold-frame until the seedlings are large enough to transfer to the open air after being hardened off. By cuttings of young shoots in sandy peat, placed in a shady situation under a hand-glass. Also by layers. Usually obtained from the woods.
Kennedya.Leguminosæ.
Seeds may be sown in spring or summer, or cuttings of rather firm side shoots may be made at the same time, and placed in peaty soil, in a close, warm frame.
Kentia.Palmæ.
Increased by seeds, placed in light, sandy soil, with heat.
Kentucky Coffee-tree.SeeGymnocladus.
Kerria.Rosaceæ.
Propagated by divisions, layers, and by cuttings of young shoots, inserted under a hand-light, or by ripened cuttings. In this country, oftener increased by ripe wood in fall.
Kitaibelia.Malvaceæ.
Seeds. May be readily propagated by divisions.
Kleinhovia.Sterculiaceæ.
Seeds. Make cuttings of the young ripened shoots, and place in sand, in heat, under glass.
Klugia.Gesneraceæ.
Seeds. Propagated usually by cuttings.
Knightia, Rymandra.Proteaceæ.
Make cuttings of ripened shoots with upper leaves on, and place in sandy soil under glass, in a very gentle bottom heat.
Kniphofia, Tritoma.Liliaceæ.
Increased by seeds, or by divisions of the crown in early spring.