Part 23 (1/2)
Piping.--This consists in drawing out the young gra.s.s, or shoots, from the joints of Pinks, etc., from May to July being the time for doing so. Place them in light, sandy soil, and cover them with a hand-gla.s.s.
Towards the end of September they may be planted out in beds or potted off in rich, light loam. In either case they must not be planted too deeply. The crust of the soil should be level with the collar of the plant. If the pots are put into a frame the plants will require very little water during winter, but as much air should be given as is possible. In March re-pot them, using 8-1/2-in. pots.
Platycodon (_j.a.panese Balloon Flower_).--Hardy and elegant herbaceous plants, requiring a sandy soil. They may be raised either from seeds or from cuttings of the young growth; they flower in July. Height, 1 ft.
Platystemon Californicus.--Pretty hardy annuals which thrive in a sandy soil. They are easily raised from seed sown in March or April, and bring forth their flowers in August. Height, 1 ft.
Pleroma Elegans.--A beautiful evergreen shrub for a greenhouse. Pot in equal parts of loam, peat, and sand. It flowers in July. Cuttings may be struck in peat in a rather warm temperature. Height, 4 ft.
Plumbago.--These pretty evergreens will grow in any soil, and can be propagated in September by cuttings of half-ripened wood having a heal, planted in a sandy soil, and kept near the gla.s.s in a greenhouse. They flower in June. Height, 3 ft. P. Occidentalis is a charming greenhouse climber. P. Capensis Alba is a greenhouse evergreen shrub, flowering in November, and growing to a height of 2 ft. P. Larpentae is good for a sunny border, in light soil: it bears terminal cl.u.s.ters of rich violet-purple flowers in September. Height, 1 ft. Plumbagoes require very little attention in winter.
Plums.--Almost any soil will grow this useful fruit. Young trees may be planted at any time, when the ground is friable, from November to March, but the earlier it is done the better. The situation should be somewhat sheltered. In exposed positions protection may be afforded by a row of damson trees. Many varieties are suitable for growing on walls or sheds, where they are trained into fans, as cordons, and other decorative designs; but it must not be overlooked that until the trees are well established a great deal of fruit is necessarily lost by the severe pruning and disbudding which is required to bring the tree into shape. A pyramid-shaped tree is useful, and is easily grown by training one straight, central shoot, which must be stopped occasionally so that fresh side branches may be thrown out, which of course must be kept at the desired length. A bush tree about 7 ft. in height is undoubtedly the best form of growth, and needs but a minimum amount of attention. In pruning wall trees the main object is to get the side-shoots equally balanced, and to prevent the growth advancing in the centre. The bush form merely require the removal of any dead wood and of cross-growing branches. This should be done late in the summer or in the autumn. The trees are frequently attacked by a small moth, known as the Plum Fortrix, which eats its way into the fruit and causes it to fall. In this case the fallen unripe fruit should be gathered up and burned, and the trees washed in winter with caustic potash and soda. For growing on walls the following kinds may be recommended: Diamond, White Magnum Bonum, Pond's Seedling, and Belle de Louvain for cooking; and Kirke, Coe's Golden Drop, and Jefferson for dessert. For pyramids and bushes, Victoria, Early Prolific, Prince Engelbert, Sultan, and Belgian Purple are good sorts. In orchards Plums should stand 20 ft. apart.
Poa Trivalis.--A very pretty, dwarf-growing, variegated gra.s.s. Plant in a moist situation in a rich, light, loamy soil. It is increased either by seed or division.
Podocarpus.--_See_ ”Cephalotaxus.”
Podolepis.--Hardy annuals bearing yellow and red and white flowers. A mixture of loam and peat is most suitable for their growth. They are easily raised from seed sown in March, and bloom from June to August.
Height, 1-1/2 ft.
Podophyllum Peltatum (_Duck's Foot, or May Apple_).--Grown chiefly for its foliage and berries, this hardy herbaceous perennial forms a pleasing spectacle when planted in moist soil under trees; it likewise makes a splendid pot-plant. A mixture of peat and chopped sphagnum is what it likes. The pots are usually plunged in wet sand or ashes on a northern border. It is propagated by cutting the roots into pieces several inches in length, with a good bud or crown on each. During May and June the plant produces small white Dog-rose-like flowers. Height, 1 ft.
Poinsettia Pulcherrima.--A stove evergreen shrub which produces lovely crimson bracts in the winter. Plant in sandy loam, give plenty of water to the roots, and syringe the leaves frequently. In early spring cut down the branches to within three or four eyes of the old wood.
These cuttings, if laid aside for a day to dry and then planted under gla.s.s, will form new plants. It flowers in April. Height, 2 ft.
Polemonium (_Jacob's Ladder_).--Hardy perennial border plants of an ornamental character and of the easiest culture. Any soil suits them, and they merely require sowing in the open either in spring or autumn.
P. Richardsoni is most commonly met with, its blue flowers being produced in early autumn. Height, 1-1/2 ft.
Polyanthus.--Sow the seed late in autumn in well-drained boxes of light, rich mould; cover it very lightly, place under gla.s.s, and water sparingly, but give enough to keep the plants moist. The seed requires no artificial heat to germinate it. The roots should be divided each year as soon as they have flowered, and fresh soil given. The single varieties only are florists' flowers. The Polyanthus is a species of primrose, grows best in a rather shady position in a loam and peat compost, and produces its flowers in May. Height, 6 in.
Polygala Chamaesbuxus.--A hardy evergreen trailing plant requiring a peat soil in which to grow. It may be increased from seed or by division of the roots. May is the time at which it blooms. Height, 6 in.
Polygala Dalmaisiana.--This showy evergreen shrub needs a greenhouse treatment. Soil--three parts peat, one part turfy loam, and a little sand. It flowers in March. To increase it, top the shoots, which will cause it to throw out new ones. Take the new growth off when it is 3 in. long, and place it under gla.s.s in a propagating house. Height, 1 ft.
The hardy annual varieties of Polygala are obtained by seed sown in peat. These flower at midsummer. (_See also_ ”Solomon's Seal.”)
Polygonatum.--These pretty herbaceous plants are quite hardy. The flowers, which are borne in May or June, are mostly white. Plants succeed best in a rich soil. They may be raised from seed, or the roots can be divided. Height, 1ft. to 3 ft.
Polygonum Brunonis (_Knotweed_).--This strong-growing creeping perennial plant is not particular as to soil so long as it can enjoy plenty of suns.h.i.+ne. The shoots root of themselves and must be kept in check, else they will choke other things. It flowers in August, after which the leaves a.s.sume beautiful autumnal tints. Height, 1 ft.
Pomegranate.--This requires a deep, loamy soil and a warm, airy situation. May be propagated by cuttings of the shrubs or the root, putting the cuttings into light, rich soil, or by layers. The double kinds of Punica, or Pomegranate, should be grafted on to the single ones. There is a dwarf kind, bearing scarlet flowers in August, which requires heat.
Poppies.--_See_ ”Papaver” _and_ ”Stylophorum.”
Portulaca.--The seeds of the hardy annual species of this genus may be sown in a sheltered open spot in spring. The half-hardy annuals should be sown thinly in boxes during March and placed in gentle heat. Harden off and plant out in May, as soon as the weather permits, in a light, dry soil where it can get a good amount of suns.h.i.+ne. Its brilliant and striking colour admirably adapts it for small beds, edgings, or rock-work; and it will succeed in dry, hot sandy positions where scarcely any other plant would live. It flowers in June. Height, 6 in.
Potatoes.--Ground intended for Potatoes should be dug deeply in the autumn, thoroughly drained, well manured and trenched, and left rough on the surface during the winter. At the beginning of February stand the tubers on end in shallow boxes, and expose them to the light to induce the growth of short, hard, purple sprouts. Allow one sprout to each tuber or set, rubbing off the rest. They may be planted at any time from the end of February to the end of March in rows 1-1/2 to 2-1/2 ft. asunder, placing the sets 6 in. deep and from 6 to 9 in.
apart. As soon as growth appears keep the ground well stirred with the hoe to prevent the growth of weeds, and when the tops are 4 to 6 in.
high ridge the earth up about them. Directly flower appears, pick it off, as it r.e.t.a.r.ds the growth of the tubers. They should be taken up and stored in October. If short of storage room dig up every other row only, and give the remaining ridges an additional covering of earth.