Arnebia.—Ornamental hardy annuals, closely allied to the Anchusa. The seeds are sown in the open in spring, and flowers are produced in July. Height, 2 ft. There is also a dwarf hardy perennial variety (A. Echioides) known as the Prophet's Flower, growing about 1 ft. high, and flowering early in summer. It needs no special treatment.
Artemisia Annua.—Pretty hardy annuals, the silvery leaves of the plant being very effective on rock-work. Sow the seed in spring where it is to flower. Height, 6 ft.
Artemisia Arborea. See "Southernwood."
Artemisia Villarsii.—A hardy perennial whose graceful sprays of finely-cut silvery foliage are very useful for mixing with cut flowers. It may be grown from seed on any soil, and the roots bear dividing; flowers from June to August. Height, 2 ft.
Artichokes.—The Jerusalem variety will flourish in light sandy soil where few other things will grow. Plant the tubers in March, 6 in. deep and 12 in. apart in rows 3 ft. asunder, and raise and store them in November. The Globe variety is increased by off-sets taken in March. Set them in deeply manured ground in threes, at least 2 ft. apart and 4 ft. from row to row. Keep them well watered, and the ground between them loose. They bear best when two or three years old.
Arum Lilies.—In warm districts these beautiful plants may be grown in damp places out of doors, with a south aspect and a background of shrubs, though, not being thoroughly hardy, it is safer to grow them in pots. They may be raised from seed in boxes of leaf-mould and sand, covering them with glass, and keeping them well watered. As soon as they can be handled, transplant them into small pots, and pot on as they increase in size. They may also be increased by the small shoots that form round the base of the corms, using a compost of loam, leaf-mould, and sand, with a little crushed charcoal. In June transplant them in the open to ripen their corms, and in August put them carefully into 6-in. pots filled with the above-mentioned compost. They need at all times a good amount of moisture, especially at such times as they are removed from one soil to another. At the same time, it is necessary to procure good drainage. It is well to feed them every other day with weak liquid manure. A temperature of 55 degrees throughout the winter is quite sufficient. When grown in the open, the bulbs should be placed 3 in. below the soil, with a little silver sand beneath each, and not be disturbed oftener than once in four years. Three or four may stand a foot apart. Stake neatly the flower stems. They flower from September to June.
Arums.—Remarkably handsome plants with fine foliage and curious inflorescence more or less enclosed in a hooded spathe, which is generally richly coloured and marked. They are hardy, easily grown in any soil (a good sandy one is preferable), and flower in July. Height, 1-1/2 ft. (See also "Calla.")
Asarum Europaeum.—This curious hardy perennial will grow in almost any soil, and may be increased by taking off portions of the root early in autumn, placing them in small pots till the beginning of spring, then planting them out. It produces its purple flowers in May. Height, 9 in.
Asclepias (Swallow-Wort).—Showy hardy perennials which require plenty of room to develop. They may be grown from seed sown in August or April, or can be increased by division of the root. A very light soil is needed, and plenty of sunshine. Flowers are produced in July. Height, 1 ft. to 2-1/2 ft.
Asparagus.—Sow in March or April, in rich light soil, allowing the plants to remain in the seed-beds until the following spring; then transplant into beds thoroughly prepared by trenching the ground 3 ft. deep, and mixing about a foot thick of well-rotted manure and a good proportion of broken bones and salt with the soil. The plants should stand 2 ft. apart. In dry weather water liberally with liquid manure, and fork in a good supply of manure every autumn. Give protection in winter. The plants should not be cut for use until they become strong and throw up fine grass, and cutting should not be continued late in the season. April is a good time for making new beds. The roots should be planted as soon as possible after they are lifted, as exposure to the air is very injurious to them.