Chapter 13
Olearia.--These evergreen shrubs thrive in peat and loam, and may be increased by division of the roots. O. Haastii has foliage resembling the Box, and a profusion of white, sweet-scented flowers in summer: a chalk soil suits it admirably. Height, 3 ft. to 4 ft.
Omphalodes Verna.--A hardy perennial which may be grown under the shade of trees in ordinary soil. It produces its flowers in March, and is increased by dividing the roots in autumn. Height, 6 in.
Oncidium Sarcodes.--Plant these Orchids firmly in well-drained pots, using equal parts of live sphagnum and fibrous peat. Give one good watering as soon as the potting is finished, and stand them in a light, warm part of the greenhouse. They will require very little more water until the roots have taken hold of the soil--only sufficient to keep the pseudo-bulbs from shrivelling--and during the winter months scarcely any moisture is needed. They flower in August. Height, 1-1/2 ft.
Onions.--Require a deep, rich, heavy soil. Where the ground is not suitable it should have had a good dressing of rotten manure the previous autumn, and left in ridges during the winter. Level the ground, and make it very firm just before the time of sowing. The seed should be sown early in March for the main crop and for salad and pickling Onions, and in August for summer use. Thin out to about 6 in. apart, excepting those intended to be gathered while small. The Tripoli varieties attain a large size if transplanted in the spring. The Silver-skins do best on a poor soil. For exhibition Onions sow in boxes early in February in a greenhouse; when about 1 in. high prick out, 3 in. apart, into other boxes; give gentle heat and plenty of air, and when they have grown 6 in. high put them in a cool frame until the middle of April, when they must be planted in the open, 1 ft. apart.
Ononis Rotundifolia (_Round-leaved Restharrow_).--A charming hardy evergreen of a shrubby nature. It will grow in any ordinary garden soil, and is increased by seed, sown as soon as it is ripe. It is most effective in clumps, and blooms from June to September. Height, 1-1/2 ft.
Onopordon.--Half-hardy perennials of a rather interesting nature and of easy cultivation. Sow the seed any time between March and June. They require the protection of a frame or greenhouse during winter, and produce flowers in July. Height, 6 in. to 8 ft.
Onosma Taurica (_Golden Drop_).--This hardy herbaceous plant is very pretty when in flower, and suitable for rock-work. It requires a well-drained vegetable mould, and to be planted where it can obtain plenty of sun. It is increased from cuttings taken in summer, placed in a cucumber frame, kept shaded for about a fortnight, and hardened off before the winter. The flowers succeed one another from June to November. Height, 1 ft.
Opuntia Rafinesquii (_Hardy Prickly Fig_).--A dwarf hardy Cactus with sulphur-coloured flowers, produced from June to August; very suitable for dry spots in rock-work. It grows best in peat with a little sand, and is propagated by separating the branches at a joint, and allowing them to dry for a day or so before putting them into the soil. Height, 2 ft.
Orange, Mexican.--_See_ "Choisya."
Orchids.--The four classes into which these charming and interesting plants are divided may be described as (1) those coming from the tropics, (2) from South Africa, (3) from the South of Europe, and (4) our native varieties. The first require a stove, the second a greenhouse, the third and fourth slight protection during winter. As their natural character differs so widely it is necessary to ascertain from what part of the globe they come, and to place them in houses having as near as possible the same temperature and humidity as that to which they are accustomed. The pots in which they are grown should be filled with fibrous peat and sphagnum moss, largely mixed with charcoal, and abundant drainage ensured. They are propagated by dividing the root stocks, by separating the pseudo-bulbs, and, in case of the Dendrobiums, by cuttings. Orchis Foliosa (_Leafy Orchis_) may be grown in the open ground in good sandy loam. When once established it is best not to disturb it, but if needed it may be increased by division, after the tops have died down. Orchis Fusca (_Brown Orchis_) may likewise be planted in the open, in a sheltered position, in fine loam and leaf-mould, the soil to be well drained, yet constantly moist.
Origanum Pulchellum.--Popularly known as the Beautiful Marjoram, this plant is useful for cutting for vases. It is perennial and hardy, and thrives in a dry situation with a sunny aspect and in a sandy soil. The bloom is in its best condition in October. The rooted shoots may be divided in spring or almost at any other period, or it may be propagated by taking cuttings in summer. Height, 1-1/2 ft.
Ornithogalum.--O. Arabicum bears a large white flower with a shiny black centre. It is a fine plant for pot culture, or it may be grown in water like the Hyacinth. It may be planted in the open early in spring in sandy loam and peat. Take it up before the frost sets in and store it in a dry place, as it requires no moisture while in a dormant state. In September the flowers are produced. Height, 6 in. O. Umbellatum (_Star of Bethlehem_) is a pretty little flower often found in English meadows, is quite hardy, and once established may be left undisturbed for years. It throws up large heads of starry flowers, which are produced in great abundance. While in a dormant state the bulbs should be kept almost dry. It is propagated by off-sets; flowers in May. Height, 1 ft.
Orobus.--These hardy perennials bear elegant Pea-shaped blossoms. The plants will grow readily in any light soil, and are easily increased by root-division in the spring, or by seeds. They flower in June. Height, 2 ft. to 3 ft.
Osmanthus.--These elegant hardy evergreen shrubs succeed best in light, sandy loam, and like a dry situation. They may be increased by cuttings of the young shoots with a little old wood attached, or they may be grafted on to common Privet. The variegated varieties are very beautiful. They grow well on chalk soils. Height, 4 ft. to 6 ft.
Othera Japonica.--A newly introduced evergreen shrub very similar to the Holly. It is perfectly hardy and may be treated in the same manner as that plant.
Ourisia Coccinea.--A hardy herbaceous, surface-creeping perennial of singular beauty as regards both leaf and flower. The soil in which it is grown must be well drained, a peat one being preferable; and the position it occupies must be well shaded from the rays of the midday sun. It flowers from May onwards to September, the cut bloom being admirable for mixing with fern leaves. As soon as new life starts in spring the roots may be divided. Height, 9 in.
Oxalis.--A genus of very pretty bulbous plants that thrive well in a mixture of loam, peat, and sand, or will grow in any light soil. Most of the tender kinds may be reared in a frame if protected from frost in the winter. After they have done flowering they should be kept dry until they begin to grow afresh. They are increased by off-sets from the bulb. The hardy species should be planted in a shady border, where they will grow and flower freely. The seeds of these may be sown in the open in spring. Some of the varieties have fibrous roots: these will bear dividing. They are equally suitable for pots, borders, or rock-work. Height, 9 in. to 3 ft.
Ox-Tongue.--_See_ "Bugloss."
Oxythopis Campestris.--A hardy perennial with lemon-yellow flowers in June and July. It will grow in any good garden soil, and is propagated by seed only, which should be sown where the plants are intended to be grown. Height, 6 in.
P
Pachysandra.--This early hardy perennial has ornamental foliage and blooms in April. It will succeed in almost any soil, and may be increased by suckers from the roots. Height, 1 ft.
Paeonies.--These beautiful flowering plants are mostly hardy enough to endure our winters. The herbaceous kinds are increased by dividing the plants at the roots, leaving a bud on each slip. The shrubby species are multiplied by cuttings taken in August or September, with a piece of the old wood attached, and planted in a sheltered situation. Tree Paeonies require protection in winter, and may be propagated by grafting on to the others, by suckers, or by layers. New varieties are raised from seed. A rich, loamy soil suits them best. Height, 2 ft.
Palms from Seed.--Soak the seed in tepid water for twenty-four hours, then put them singly 1 in. deep in 2-in. pots filled with equal parts of loam, leaf-mould, and sand. Cover the pots with glass and stand them in the warmest part of a hothouse. Shade from strong sunshine, and keep the soil just moist. Re-pot as soon as the roots have filled the old ones.
Pampas Grass.--_See_ "Gynerium."
Pampas Lily of the Valley.--_See_ "Withania."
Pancratium.--A handsome class of plants. Their habit of growth is somewhat like that of the Amaryllis. They are admirably adapted for growing in pots in the greenhouse. They may also be planted in the open ground under a south wall. The bulbs should be placed in a composition of three parts light, sandy loam and one of vegetable mould. They are increased by off-sets from the roots, or by seeds, by which the new varieties are obtained. Height, 1 ft. to 2 ft.
Pandanus Veitchi (_Variegated Screw Pine_).--For table decoration or vases this is a most useful plant. It requires a warm greenhouse where a temperature of 60 or 70 degrees can be kept up throughout the year, and grows well in equal parts of peat and loam with one-sixth part sand. During the autumn a little liquid manure is beneficial. In the winter months it should be watered carefully, but in the summer it is improved by syringing with warm water. It is propagated very easily by suckers taken off in spring or summer, placed in a temperature of 75 degrees.
Panicum.--Handsome ornamental grasses. They will grow in any soil or situation. P. Capillare is an annual, suitable for bouquets or edgings; it is increased by seed. P. Altissimum, an annual, and P. Sulcatum, a most elegant greenhouse plant, are fine for specimens. P. Plicatum is highly ornamental and hardy, but is best grown as a conservatory or window plant; it has a Palm-like appearance, and is of quick growth. Most of the plants flower in July. They may be propagated by seed or by division of the roots. Average height, 1-1/2 ft.
Pansies (_Heartsease_).--Grow well from seed sown in July or August on a raised bed of light earth. They may also be increased from cuttings taken in August, September, April, or May, selecting young side-shoots and planting them in light earth mixed with silver sand. The cuttings should be kept in a cool frame, moderately moist, and shaded from the hot sun. They can likewise be increased by layers, merely pegging them down and not slitting them on account of their tendency to damp off. They may also be increased by dividing the roots in April or May. They should be planted where they will get all the morning sun, yet be sheltered from mid-day rays; in an open and airy situation, yet protected from cutting winds. While the plants are blooming they should be supplied with liquid manure.
Papaver (_Poppy_).--These showy flowers are most at home in a rich, light soil. They are easily raised from seed sown where they are intended to bloom. The perennials may also be increased by dividing the roots. They flower at midsummer. Height varies from 1 ft. to 3 ft.
Pardanthus Chinensis.--_See_ "Iris."
Parsley.--In order to grow Parsley to perfection it is necessary that the ground be well drained, as the roots and stems must be kept dry, and the soil should be rich and light. Three sowings may be made during the year: the first in spring for late summer and autumn use, the next in June for succession, and another in August or September for spring and early summer use. Thin out or transplant, to 6 in. apart. Parsley takes longer than most seeds to germinate; it must therefore be watched during dry weather and watered if necessary. Plants potted in September and placed in a cold frame, or protected in the open from rain and frost with a covering of mats supported by arches, will be valuable for winter use.
Parsnips.--These succeed best in a rich soil, but the application of fresh manure should be avoided, as it induces forked and ill-shaped roots. Let the ground be trenched two spits deep and left ridged up as long as possible. As early in March as the weather will permit level the surface and sow the seed in drills 15 in. apart, covering it with half an inch of fine soil. When the plants are 2 or 3 in. high, thin them out to 9 in. apart. They may be taken up in November and, after cutting off the tops, stored in a pit or cellar in damp sand, or they may be left in the ground till required for use.
Passion Flower.--Cuttings of the young shoots strike readily in sand under glass. The plant likes a good loamy soil mixed with peat. A sheltered position with a south or south-western aspect should be assigned those grown out of doors, and the root should be well protected in winter. The flowers are borne on seasoned growth of the current year: this fact must be considered when pruning the plants. During the hot months the roots require a copious supply of water, and the foliage should be syringed freely. Passiflora Cærulea is fine for outdoor culture, and Countess Guiglini makes a capital greenhouse plant.
Pavia Macrostachya.--This is a deciduous hardy shrub or tree which bears elegant racemes of white Chestnut-like flowers in July. Any soil suits it. It is propagated by layers or by grafting it on to the Horse-chestnut. Height, 10 ft.
Peaches.--These are best grown on a strong loam mixed with old mortar; though any soil that is well drained will produce good fruit. When possible, a south wall should be chosen; but they are not particular as to position, providing they are afforded shelter from cold winds. November and February are the most favourable months for planting. The roots should be carefully arranged at equal distances apart, 3 or 4 in. below the surface of soil, and then covered with fine mould. Avoid giving manure at all times, except when the trees are bearing fruit heavily. Train the shoots about 6 in. apart, removing all the wood-buds except one at the base of the shoot and one at the point. Keep the flowers dry and free from frost by means of an overhead shelter, to which tiffany or canvas can be attached, which should, however, only be used so long as the cold weather lasts. To ensure good fruit, thin the same out to 6 in. apart as soon as it attains the size of a small pea, and when the stoning period is passed remove every alternate one, so that they will be 1 ft. apart. After gathering the fruit, remove any exhausted and weak wood, leaving all that is of the thickness of a black-lead pencil. To keep the foliage clean, syringe once a day with water; this may be continued until the fruit is nearly ripe. The following may be recommended for outdoor cultivation:--Hale's Early, Dagmar, and Waterloo for fruiting in July or August; Crimson Galande, Dymond, and the well-known Bellegarde for succession in September; and Golden Eagle for a late sort. When planted in quantities, Peaches should stand 20 ft. apart.
When grown under glass a day temperature of 50 degrees, falling to 45 degrees at night, is sufficient to start with, gradually increasing it so that 65 degrees by day and 55 by night is reached at the period of blossoming. Syringe the leaves daily until the flowers are produced, then discontinue it, merely keeping the walls near the pipes and the paths damp. As soon as the fruit is set the syringing should recommence. Water of the same temperature as that of the house should in all cases be used. When the fruit begins to ripen, cease once more the syringing until it is gathered, then admit air freely, wash the trees daily, and apply liquid manure to the roots in sufficient quantities to keep the soil moist during the time the trees are at rest. Rivers's Early, Pitmaston Orange, Dagmar, and Royal George are all good under glass.
Pears.--Wherever Apples are a success Pears will grow. As a rule, they are best grown dwarf. On light soils they should be grafted on to Pear stocks, but on heavy soils they are best worked on the Quince. The fruiting of young trees may be accelerated by lifting them when about five years old, spreading out the roots 1 ft. below the surface of the soil, and mulching the ground. The mulching should be raked off in the spring, the ground lightly stirred with a fork and left to sweeten, and another mulching applied when the weather becomes hot and dry. In pruning, leave the leading branches untouched, but let all cross shoots be removed, and the young wood be cut away in sufficient quantity to produce a well-balanced tree, and so equalise the flow of sap. Some of the pruning may be done in summer, but directly the leaves fall is the time to perform the main work. A good syringing once a week with the garden hose will keep the trees vigorous and free from insects. Should scab make its appearance on the leaves, spray them occasionally with Bordeaux Mixture, using the minimum strength at first, and a stronger application afterwards if necessary. There are over 500 varieties of Pears, so it is no easy matter to give a selection to suit all tastes, but a few may be named as most likely to give satisfaction. Louise Bonne de Jersey succeeds in almost any soil and in any situation, is a great favourite, and ripens its fruit in October. Beurré Giffard makes a fine standard, and ripens in July. Beurré Hardy is delicious in October and November. Doyenné du Comice is one of the best-flavoured, and is very prolific. Beurré d'Amanlis ripens in August. Williams's Bon Chrêtien, Aston Town, Pitmaston Duchess, Clapp's Favourite, Comte de Lamy, and Josephine de Malines are all reliable for dessert, while for stewing purposes Catillac, Black Pear of Worcester, Verulam, and Vicar of Winkfield are among the best. In orchards standards should be from 20 to 25 ft. apart; dwarfs 12 ft. to 1 rod.
Peas.--For the production of heavy summer and autumn crops a rich and deeply-stirred soil is essential, one of the best fertilisers being well-decayed farmyard manure; but for the earliest crop a poorer soil, if deep and well pulverised, will give the best results. Peas under 3 ft. in height do not require sticking, but they can be more easily gathered if a few small twigs are used to keep the haulm off the ground. If sown in successive lines the space between the rows should correspond with the height of the variety grown. A good plan is to arrange the rows 10 or 15 ft. apart, and crop the intervening spaces with early dwarf vegetables. The earliest varieties may be sown from November to February, on the warmest and most sheltered border: these may be gathered in May and June. The second early round, varieties, if sown from January to April, will be ready for gathering in June and July. The main crop round varieties may be sown from February to May: these will be ready to gather in July and August. The early wrinkled varieties may be sown from March to June, for gathering between June and September. Sow main crop and late varieties at intervals of fourteen days from March to May: these will be ready to gather in July, August, and September. When the plants are a couple of inches high draw the earth neatly round them, and stake the taller varieties as soon as the tendrils appear. Keep them well watered in dry weather, and if on a light soil a mulching of manure will be beneficial. As soon as the pods are setting apply weak liquid manure to the roots when the ground is moist.
Peas, Everlasting (_Lathyrus Latifolia_).--These well-known and favourite hardy perennials are very useful for covering trellises, etc. They will grow in any garden soil, and may be raised from seed sown early in spring in slight heat. Where there is no greenhouse or frame the seed may be planted, about 1/2 in. deep, round the edges of pots filled with nice, light soil, and covered with a sheet of glass, keeping the soil moist till the seed germinates. When the plants are strong enough they may be placed in their permanent quarters. They bloom from June to September. Old roots may be divided. Height, 6 ft.
Peas, Sweet.--These most beautiful and profuse blooming hardy annuals will grow almost anywhere, but they prefer a dry soil that is both rich and light. The seed should be sown as early in March as practicable, and in April and May for succession. When the plants are 2 or 3 in. high a few twigs may be placed among them, to which they will cling. The flowers are produced in July, and the more liberally they are gathered the longer the plants will continue to bloom. Height, 3 ft.
Pelargonium.--The shrubby kinds will grow well in any rich soil; loam and decayed leaves form a good compost for them. They require good drainage and plenty of air and light while in a vigorous state. Cuttings root readily in either soil or sand, especially if placed under glass. Most of the hard-wooded varieties are more easily increased by cuttings from the roots. The tuberous-rooted ones should be kept quite dry while dormant, and may be increased by small off-sets from the roots.
Pentstemon.--This charming hardy perennial is deserving of a place in every garden. It may be grown in any good soil, but a mixture of loam and peat is most suitable. The seed may be sown in April, and the plants transferred when strong enough to their flowering quarters; or it may be sown in a sheltered position during August or September to stand the winter. It may also be increased by dividing the roots in spring, as soon as growth begins. Cuttings of the young side-shoots about 6 in. long may be taken at any period--the middle of September is a good time; these should be placed under a hand-glass in sandy loam and leaf-mould. These cuttings will flower the first year. It blooms from May to October. Height, 2 ft.
Peppermint.--This may be grown on any damp or marshy soil, and increased by dividing the roots.
Perennials.--These are plants that die down during the winter, but spring up and produce new stems annually. Some, as for instance Antirrhinums and Pansies, flower the first season, but usually they do not bloom till the second season. Many of the species improve by age, forming large clumps or bushes. The stock is increased by division of the roots, which, if judiciously done, improves the plant. Like annuals, they are divided into classes of Hardy, Half-hardy, and Tender plants.
Hardy perennials do not require artificial heat to germinate the seeds, or at any period of their growth, but are the most easily cultivated of all plants. Seed may be sown from March to midsummer, transplanting in the autumn to their flowering quarters; or it may be sown in August and September in a sheltered position to stand the winter.
Half-hardy plants require artificial heat to germinate their seed, and must be gradually introduced into the open. They may be sown during March and April in frames or a greenhouse, when many will bloom the first season. If sown between May and the end of August they will flower the following spring and summer. They require protection during winter, such as is afforded by a cold pit, frame, or greenhouse, or the covering of a mat or litter. Tender perennials may be sown as directed above, but the plants should be kept constantly under glass.
Some perennials, such as Pinks, Carnations, Saxifrages, etc., do not die down, but retain their leaves. These are called evergreen perennials.
Pergularia.--Very fragrant twining plants, suitable for trellis-work, arbours, etc. A rich soil suits them best. They are easily increased by cuttings sown in sand under glass. They flower at midsummer. Height, 8 ft. to 12 ft.