Gasteria Verrucosa.—This plant grows best in pots of turfy loam and leaf-mould, to which has been added a little old mortar. Good drainage is essential. Water freely in summer, and keep just moist in winter. Keep the foliage clean by sponging. Give plenty of light, and during warm weather turn the plants out of doors.
Gastrolobium.—Elegant evergreen shrubs which flower in April and May. They are most suitable for adorning the greenhouse, and grow best in a soil of loamy peat and sand. Cuttings of half-ripened wood planted under glass will take root. Height, 2 ft.
Gaultheria.—Dwarf, creeping evergreen shrubs, having dark foliage and producing white flowers in May, June, or July. They require to be grown in peat, and are increased by layers. G. Procumbens is suitable for rockeries, as it only grows to the height of 6 in. G. Shallon attains the height of 2 ft.
Gaura Lindheimeri.—This free-flowering, hardy, herbaceous plant will thrive in any light, rich soil. It bears elegant spikes of white flowers from May onwards, followed by red bracts in September, and is readily propagated by seeds. Height, 4 ft.
Gazania Splendens.—A showy greenhouse plant. It may be planted in the open in warm positions, but will require protecting in winter. Grow it in peat and loam. Cuttings will strike if placed in sand under glass. It flowers in July. Height, 1 ft.
Genethyllis.—Greenhouse evergreen shrubs which thrive best in sandy loam and peat. Cuttings of the young wood planted in the same soil and plunged in heat will take root. Their flowering season is in August. Height, 3 ft.
Genista (Broom).—G. Canariense is an exceedingly ornamental and free-flowering greenhouse shrub. It should be planted in a mixture of loam, peat, and sand. Young cuttings inserted in sand under a glass take root readily. It blooms in June. Height, 2 ft. Hardy species of Genista may be placed in the front of shrubberies. They are increased by seeds or by layers.
Gentians.—The herbaceous kinds do best in a light, rich soil, such as loam and peat mixed with vegetable mould. The annuals are raised from seed sown as soon as it is ripe; if left till spring before it is sown it will probably not come up till the second year. The perennials are increased by dividing the roots. Both of the latter kinds do best in a dry, sandy soil. Gentiana Acaulis, or Gentianella, is very suitable for edgings, or for rock-work; it is an evergreen creeper, and bears large trumpet-shaped flowers of rich ultramarine blue. All the Gentians need plenty of free air, and some of them moisture at the roots. Bloom in July. Height, 4 in. to 2 ft.
Geranium Argentium(Silvery Crane's-Bill).—This hardy perennial alpine is very effective on rock-work, especially in front of dark stones; but provision must be made for its long tap roots. A rich, deep loam suits it well. Its seeds germinate freely when sown in peat and sand. Flowers are borne from May to July. Height, 6 in.
Geraniums.—Take cuttings in July or August, and let them he to partially dry for twenty-four hours before planting. When rooted pot them off in 60's, and keep them under glass during the winter at a temperature of 55 degrees. If the cuttings are taken in September put three or four slips in a 48-size pot. In the spring they should be re-potted singly and hardened off as early as possible. A suitable soil for them is made by mixing two parts of good turfy loam, one of leaf-mould, one of well-decomposed cow-dung, and a good proportion of silver sand. Bone dust is an excellent addition to the soil. Old plants stripped of their leaves may be packed in sand during the winter, and re-potted in spring.