Mustard and Cress.—Mustard is the native white mustard eaten in its seed leaves; and cress is an annual cruciferous plant, introduced before 1548, but from what country is unknown. They are both of the easiest culture, and will not only grow in any soil or situation, but may even be raised for the table by spreading the seed in a saucer on wet flannel. The flour of mustard is made from the ground seeds of the black mustard, which is cultivated extensively in some parts of England for that purpose.
Corn Salad or Lamb Lettuce, Winter Cress, Burnet, Tansey, and many other plants are occasionally used in salads, particularly on the Continent, but they are seldom grown for that purpose in England.
Celery is frequently used in salads; and it is interesting, as being so greatly improved by cultivation as scarcely to be recognized; for in its wild state it is a British plant called smallage, which grows in ditches, and is scarcely eatable. In gardens, celery requires more manure than any other vegetable, except the cabbage tribe. The seed for the principal crop of celery is generally sown in March or April, and the seed-bed should be formed of equal parts of fresh dark loamy soil, and old rotten dung. When the plants are about two or three inches high, they are pricked out into another bed made of very rich soil, six or seven inches deep, on a hard bottom; and when they are about a foot high, they are transplanted into trenches for blanching. The trenches are made four feet apart, eighteen inches wide, and twelve deep; and they are filled nine inches high with a rich compost of strong fresh soil and rotten dung. The plants are taken up with as much earth as will adhere to the roots, and the side-shoots or offsets are removed from the central stems; they are then set by the hand, nine or ten inches apart, in the centre of each trench, and well watered. As the plants in the trenches grow, the earth is gradually drawn up to them, a little at a time, taking care never to let the earth rise above the heart of the plant; and this earthing up is repeated five or six times, at intervals of about ten days or a fortnight, till the plants are ready for use. Thus treated, a single plant of celery of the solid kind has been known to weigh nine pounds, and to measure four feet in length.
Water cress is generally gathered wild, but it may be cultivated in gardens where there is a clear running stream, on a sandy or gravelly bottom. The plants are disposed in rows parallel with the stream, about eighteen inches apart, in shallow water; but four or five feet apart if the water be very deep, as if nearer together they will check the stream. Thus treated, the plants may be cut at least once a week during the whole summer. The beds must, however, be cleared out and replanted twice a-year; and when this is done, all the plants are taken up, divided and planted again in the gravelly bed of the stream, a stone being laid on each to keep it in its place.
Pot Herbs.—Of these parsley is a hardy biennial, a native of Sardinia, introduced before 1548. It is generally sown in a drill in February or March, and this will supply leaves all the summer. The plants do not seed till they are two years old. The curled variety is preferred for garnishing. Tarragon is a strong-smelling perennial from Siberia, introduced before 1548. It is principally used for making Tarragon vinegar. Fennel is a perennial, which, when once introduced, spreads every where, and can scarcely be eradicated. Chervil is an annual used for garnishing, and sometimes in salads, and the common Marigold is an annual, a native of the South of Europe, introduced before 1573, but now seldom grown except in cottage gardens.
Sweet Herbs.—These plants, though called in gardening-books sweet herbs, are mostly aromatic shrubs; such as thyme, sage, &c.
Thyme.—There are two kinds of this delicate little shrub cultivated in gardens; the common and the lemon: both are natives of the south of Europe, and were introduced before 1548. Young plants are generally raised by division of the root, or from offsets slipped off the branching roots in spring or autumn; they grow best in poor dry soil, or lime rubbish.
Sage is a much taller-growing shrub than thyme. It is a native of the south of Europe, and was introduced before 1597. It is propagated by slips, or by cuttings of the young shoots taken off in May or June; but as the plant is very long-lived it seldom wants renewing. It requires the same kind of soil as thyme.
Mint.—There are three kinds grown in gardens: the common, or spear mint, which is the kind boiled with peas, and used for mint-sauce, &c.; the peppermint, comparatively little cultivated, and only used for distilling; and the penny-royal. They are all British perennials, and are propagated by dividing the root, making cuttings, or taking off offsets. All require rather a moist and strong soil.
Marjoram.—There are four kinds in cultivation: the pot marjoram, which is a low shrub, a native of Sicily, introduced in 1759, and propagated by slips; the sweet, or knotted marjoram, a hardy biennial, a native of Portugal, introduced in 1573, and sown every year from seed generally ripened in France; the winter marjoram, a hardy perennial, a native of Greece, introduced before 1640, and propagated by cuttings or slips; and the common marjoram, a perennial, and a native of Britain. The first three kinds require a light dry soil, and the last a calcareous soil, and sheltered situation.