SWEET PEA

Lathyrus odoratus. Hardy climbing annual The history of the Sweet Pea can be traced back for more than two hundred years; and it is almost as fascinating as an exhibition of the flowers. Recent improvements in this highly popular subject include an amazing diversity



of colours, a marked increase in the number of flowers on each stem, and an extraordinary enlargement in their size. A modern list may run into hundreds, but those who grow every known variety find that there are many close resemblances, arising no doubt from simultaneous introductions by hybridists who have experimented on similar lines. Enthusiastic growers of Sweet Peas are no longer content with a limited number of named varieties, for it is obvious that in competitions where fifty or a hundred bunches have to be staged for certain prizes, a large and representative collection must be grown. For general garden decoration, however, and to provide sprays for the adornment of homes, the Giant-flowered class, offered under colours only, will continue to be extremely popular. The change in character and the increased usefulness of Sweet Peas have necessitated a revolution in the methods of culture. The freer growth and more robust habit demand greater space than was formerly allowed. Instead of crowded rows of attenuated plants, producing a meagre return of small flowers, poor in colour, it is now the practice to prepare the ground by deep trenching and liberal manuring, and to give every plant ample space for full development both in rows and in clumps. In the ensuing paragraphs we outline the cultural routine which should be followed as nearly as possible by those who desire to insure a long-continued supply of the very finest flowers. But where circumstances do not permit of these recommendations being adopted in full, the details may be modified according to the materials at command and the requirements of the cultivator. It is usual to commence the preparation of the ground in autumn. Trenching is of paramount importance, for the roots of the Sweet Pea require a considerable depth of good soil in which to ramify for the support of robust healthy plants capable of producing handsome flowers over a long season. Where the surface soil is shallow, care must be exercised to avoid bringing uncultivated subsoil to the top, and it is well worth incurring a little extra trouble to provide a sufficient depth of fertile material for full root development. Therefore dig out a wide trench and place the good top soil on one side. Then remove and discard the subsoil to a depth of twelve inches and, after breaking up the bottom of the trench with a fork or pickaxe, replace with an equal quantity of decayed manure, leaves, old potting soil or any other suitable stuff that may be on hand. Finally return the top soil to its original position. The use of manure needs discrimination, and in fixing the quantity, as well as in selecting the most suitable kinds, due consideration must be given to the character of the soil. For light land, four barrow-loads of well-rotted farmyard manure per square pole will make an excellent dressing, but a rather smaller amount will suffice for heavy ground. In place of farmyard manure an unlimited quantity of leaf-soil, if obtainable, may be used, and it is also a good plan to dig in any available green refuse. Garden ground which for some years previously has been kept in a state of high cultivation by the liberal use of natural manure will not, as a rule, need further help in this direction, but it should receive a good dressing of lime. Indeed, any soil in which Sweet Peas are to be grown should contain not less than two per cent. of lime. The employment of artificial, as well as organic, manures is essential in any first-class scheme of cultivation. But here a word of warning is necessary. Nitrogenous manures in any form are harmful to the plant when applied in large quantities, and are liable to predispose it to disease, except on extreme types of sandy soil. Heavy ground should be dressed with seven pounds of basic slag in autumn and two pounds of sulphate of potash in spring. On light soils apply in spring four pounds of superphosphate of lime and two pounds of sulphate of potash. The quantities stated in each case are sufficient for a square pole of ground. Wood ashes (in a dry state) are also of great value, and these should be raked in a little in advance of planting out. The special preparation of the soil just described entails the raising of plants in pots or boxes in readiness for transfer to the open as early as weather permits in spring. The finest flowers are undoubtedly obtained from an autumn sowing, and about the middle of September may be regarded as the best period for putting in the seed. This early commencement possesses the advantage of allowing ample time for the development of sturdy, well-rooted plants, which will not only bloom in advance of those sown in spring but will remain in flower for an unusually long period. Sow in light porous soil, and either three-inch pots, pans or boxes may be used. Place in a cold frame and keep the lights down until the seeds have germinated, but afterwards the frame should never be closed except during severe weather. There must be no misunderstanding on the question of air-giving. The Sweet Pea is almost hardy, and robust healthy seedlings, grown as nearly as possible under natural conditions, are wanted. Therefore to subject the plant to artificial heat will only defeat the object in view. A current of air should be admitted to the frame day and night, and the lights may be entirely removed on all favourable occasions. But the seedlings will need protection from excessive moisture, for if too wet at the roots they are liable to injury from frost. When four pairs of leaves are formed, stop each plant once, and after a little further progress has been made transplant singly into three-inch pots. Keep the pots in the frame, giving only such protection from hard weather as may be absolutely necessary, and plant out on the first suitable opportunity. In the South transplanting may be possible late in February or at the opening of March, but a month later will be safer in districts north of the Trent. Those who for any reason do not find it convenient to sow in autumn may start the seed early in the year--from mid-January onwards, according to the district. The general principles described in the preceding paragraph apply equally to spring sowings, but it may be well to say that there must be no attempt to hasten growth by the application of a high temperature. A frame will afford all the protection necessary, and even a box covered with glass and placed in a sheltered spot will be found serviceable for raising seedlings. Before planting out, the top soil of the ground prepared in autumn must be well worked and made friable. The disposition of the plants, and the method adopted for staking them, will, to a great extent, depend on the precise purpose for which the flowers are required. For garden decoration single rows answer well, and the plants should be spaced one foot apart. Or, if preferred, put out in clumps of three to five plants, allowing a diameter of from nine to fifteen inches. Carefully remove the plants from the pots or boxes in which they were raised, disentangle the roots and shake them quite free from soil. Make a hole of the necessary depth, and allow the roots to descend into the ground to their full extent, which may be as much as two feet in the case of well-grown specimens from autumn-sown seed. Give support immediately with well-branched twigs, and it is important that the plants be kept perfectly upright. Finally stake with bushy hazel sticks eight to ten feet in height, or taller still where the ground has been generously prepared. Long-stemmed flowers free from blemish are essential for show work and for the highest forms of house decoration, and to insure an adequate supply over an extended period the following method, which is adopted by some of the most successful exhibitors, is strongly to be recommended. The plants are put out in double rows one foot apart, and spaced a foot apart in the lines. Each plant should carry two shoots only, both of which must be provided with a rod of bamboo, ash, or hazel, ten to twelve feet in length. For this double cordon system the rods will stand six inches apart in the rows, and it is desirable to make them secure against damage from high winds. Insert a stout pole at each end of the row, and about seven feet from the ground-level fix to each pole a substantial wooden crosspiece a little more than a foot in length. From these cross-pieces tightly stretch strands of wire, to which securely tie the rods. As growth develops commence disbudding promptly, regularly remove all laterals and tendrils, and tie each cordon to its supporting rod with raffia as often as may be necessary. After transfer to the open ground the plants must never be allowed to become dry at the roots. Keep the hoe going between the rows, especially after the soil has been beaten down by rain. The blooming period can be prolonged by the simple expedient of daily removing the dead or faded flowers. The ripening of only a few seed-pods speedily puts a stop to flowering. In the open ground seed may be sown in spring from February to May, and successional sowings at intervals of a fortnight will extend the supply of flowers far into autumnal days. Even where a few clumps only can be grown it is unwise to depend on a single sowing. Autumn sowings outdoors are often made in September or October where a warm soil and favourable situation can be insured. Sweet Peas have two principal foes, the slug and the sparrow. Against the former the usual precautions, such as ashes, old soot, lime, and various traps, are available; and the latter must by some means be prevented from doing mischief. After the buds show through the soil, it is generally too late for the adoption of remedies. Nearly all the heads will be found nipped off and laid ready for inspection. One could almost forgive the marauders were food the object, but the birds appear to commit havoc from pure wantonness, and whole rows are sometimes destroyed in a single morning. Early sprays are so much prized that the practice of flowering Sweet Peas in pots under glass is yearly increasing, and for this purpose seed must be sown in August or September; the plants to be kept slowly moving during the dark days. In February the growth will be more rapid, but it is important to give the plants the hardiest possible treatment. In April, if properly managed, there will be a brilliant display. The winter-flowering race blooms freely at a still earlier period, although the plants are less vigorous than other varieties.

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