HORTICULTURE. This term is derived from the Latin, hortus-a garden, and cultura-cultivation; and horticulture originally meant the cultivation of a garden in contrast to agri culture or the cultivation of fields. Field culture related originally to the production of cereals, grass and roots for fodder, while the garden was cultivated for the production of vegetables, fruit and nuts for use in the house and of flowers to beautify it. In early days, horticulture and gardening were synonymous terms, but horticulture has come to mean more than gardening. With the development of the town areas in the industrial ages, all the necessary fruits, flowers and vegetables could not be produced in the gardens, and in consequence these crops came to be grown in the fields, where they displaced cereals, roots or grass, in varying quantities. In places like England and Belgium, it would seem that this development increased simultaneously with the rise and intensification of industry; but it spread in advance of industry in North America, South Africa, Australia and New Zealand, for horticultural "Products, even for export, found a better market than the ordinary agricultural crops. Present day horticulture still means gardening, i.e., gardening in the home gardens, on the allotments and in the public parks, but the term also embraces the production of crops of fruit, flowers and vege tables wherever grown. It has developed into an industry of magnitude in England, Belgium, France, the Netherlands, United States and Canada, New Zealand and Tasmania, while in other countries, such as the South American republics, it has barely secured a footing.
In all these countries the departments of agriculture deal with horticulture usually through a separate department. Admittedly horticulture deals with crop production, and therefore has a close relationship to agriculture, but yet there is a distinction which is officially recognised in many acts of parliament. In some acts the term agriculture is defined specially as including horticulture, but where no such definition is made horticulture often has been deemed to be excluded. Horticulture, of course, is of intense interest to large numbers of people, and its work is seen every where. Fruit, flower and vegetable production in the fields, pri vate gardens and allotments, floriculture in the public parks, gar dens and wayside places; even in the hearts of the great towns it may be seen practised in window boxes or roof gardens.
The Nursery Trade.—One of the important branches of hor ticulture is the nursery trade, for it supplies the industry and the public with plants, shrubs and trees for growing. The mem bers of the trade have to be very skilled and technical, for theirs is the responsibility to choose and propagate the best varieties, true to name, to care for and develop the best strains, and to propagate and raise the baby plants until they reach the stage when they can leave the nursery grounds and fend for them selves in the fields of the market gardeners and fruit growers or in the private gardens of the public.
The nurserymen of to-day look far afield, making their pur chases and selling their stocks in all countries where plant im portation has not been forbidden. At times they assist collec tively in sending explorers to wild and remote places to collect new plants of beauty.
Plant Raising.—All plants may be raised from seed, though some may be propagated more easily in other ways. The seeds of some yield a plant which flowers, produces seed and dies, all in the same year. Such one-year plants are called annuals, and in clude asters, balsam, calceolaria, candytuft, clarkia, cinerarias, eschscholtzia, annual delphiniums, linaria, annual lupins, mi gnonette, nasturtium, nigella, nemesia, annual poppies, sunflowers, stocks, sweet peas and zinnias. Seeds of these should be spring sown on good land. For earlier plants seed may with advantage be sown in sandy loams during January in heat, a practise specially recommended for asters, stocks and zinnias.
Other flowers, and f et that matter vegetables, take one year to produce the plant, which gives flowers and seeds in the following year ; these are known as biennials. Canterbury bells, antirrhinums, scabious and wallflowers are well-known biennials. Seed sown during the summer or autumn should be transplanted to single plants in the autumn to flower the following spring and summer.
There is a third class of plants which, after flowering, does not die; the foliage may ripen and die away in the autumn, but the roots persist so that with each spring and summer foliage and flowers are sent forth. Plants of this class are known as perennials, and they embrace most of our important plants of the herbaceous border. Aquilegia, auricula, begonia, calceolaria (bedding), cam panula, carnations, Michaelmas daisies, delphiniums, peonies, lupins, phlox, perennial poppies, pyrethrums, are examples of per ennial plants. Stocks of these may be raised from seed sown any time during the summer. Transplanted single roots increase in size annually and these may be divided to make more plants, a form of propagation usually adopted for perennials.
Some plants—antirrhinums, carnations, chrysanthemums, geraniums, calceolarias, arabis and aubretia, heaths, etc.--are in creased by planting stem cuttings in pure sand in heat under moist conditions. They soon take root and make fresh plants. For plants like the phlox and seakale it is preferable to use a root cutting which on planting develops aerial branches.
Some plants give of their best when grown on roots which are not their own. Thus, varieties of roses are grown on the dog rose, the manetti, or the rugosa; the rhododendron on the common R. ponticum; apple trees on the crab or paradise stock; pears on the quince; cherries and plums on the wild stocks. This is a very convenient method of increasing plants, for the stocks may be grown and got ready to receive the particular variety which is joined on by grafting or budding. Grafting is a spring operation usually done for apples, pears, rhododendrons and many flower ing shrubs. Budding is done in mid-summer and is more com monly used for roses, plums, peaches, etc. Where plants are difficult to propagate from seed or from cutting or by budding or grafting they are often layered, i.e., a stem slightly cut is pegged down to the ground and the cut part covered with soil. The obsti nate plants may be coaxed by such means to send out roots.
In England the land devoted to nursery work is estimated at Io,000 acres, with an annual output of stock valued at £5,000,000. Holland, France and Germany have very large and important nursery trades. Those of the United States and Canada are fast developing.
Seed Production and Harvesting.—To a very large extent the flowers and vegetables of the gardens and fields are raised from seed sown annually. The horticulturist needs supplies true and of good germination. To secure seed that when sown will give good germination, it must be grown in certain localities and harvested during special weather conditions ; in consequence localities be came famous for certain seeds. Home seed saving fell out of fashion, and a special horticultural seed industry has taken its place. Horticultural seed firms of world-wide reputation exist in many countries. Perhaps the locality of first importance as a horticultural-seed district is California. The Californian climate is especially suitable for seeds of onion, lettuce, carrot, radish, sweet peas, zinnias and many flower seeds.
Similarly France, and especially the south of France round St. Remis, is suitable for just the same kinds, and these are produced in considerable quantities. The island of Vancouver, B.C., seems favourable for seeding flowers and a small industry has developed. There are many other places where the climate seems suitable and where important seed areas may develop, as for example South Africa. To seed the cauliflower a mild winter season is es sential, for which reason Italy proves very desirable. In the neighbourhood of the bay of Naples field upon field of cauli flowers are seeded, from whence supplies go to all parts.
In the Netherlands the climate is more suitable for seeding culinary peas, of which there is a large and important production. England's climate is none too kindly for seed production, but is suitable for seeding peas and sweet peas in some quantity and such vegetables as cabbage, savoys, broccoli and Brussels sprouts. English raised seed of these vegetables enjoys a good reputation and finds markets in the United States, Canada, India and many other countries. In England about 4,850 occupiers of holdings are engaged in producing crops for seed.
The seed is formed on the plant after the female portion of the flower has been fertilised, and it is important that the pollen should come from flowers of the same variety, for if they do not crossing will occur. Many vegetables and flowers are fertilised by wind blown or insect carried pollen, so that the difficulties in keeping stocks pure are many. In practice, blocks of the same kind are grown in isolation and far removed from any foreign source. In addition, the parent plants are rogued very carefully at the time when differences in growth disclose the intruders. Seed saving of Brassicae present a most difficult feature, for all kinds of cabbage will fertilise each other and also the Brussels sprouts, savoys, broccoli and wild mustard; so that the isolation of each kind of these plants needs great care.
The seed has to be harvested ripe and dry, threshed from the haulm and stored under appropriate conditions or good germina tion is not retained. Purity and good germination are the important essentials. In consequence of this several countries, the United States, Canada, England, Scotland, Ireland, Switzerland, Denmark, France, Holland, etc., have established official seed testing stations where seeds have to be tested before they may be offered for sale to the public. Legislative measures compelling this are embodied in "seeds acts" which generally lay down standards of purity and germination for each class of seed. For England the standards of germination must not be less than: peas 7o%, dwarf and broad beans 75%, runner beans 6o%, turnips 75%, cabbage 7o%, kale 7o%, kohl rabi 6o%, swede 7o%, Brussels sprouts 7o%, broccoli 6o%, cauliflower 6o%, carrot so%, parsnip 45%, beet 5o%, onion 6o%. Somewhat similar standards are in existence in other countries. The Government of Canada has gone further with control measures, so that it is illegal to sell seed of any varieties unless the name has been registered by the Canadian Government as that of a distinct variety. Trial grounds are maintained at the central experimental farm at Ottawa for testing all kinds under the plant registration scheme.