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.
Gerardia.--These hardy perennials form pyramidal bushes bearing
Pentstemon-like flowers, thickly set and varying in colour from
light pink to dark purple. A peat soil suits them best. They may be
propagated by cuttings placed under glass, but are best grown from
seed. July is their flowering season. Height, 1 ft. to 2 ft.
German Seeds.--These require to be sown in a cold frame in seed-pans,
in the greenhouse, or under a handglass, in good, rich compost,
composed of old turf, leaf-mould, some well-rotted manure, and silver
sand. The seeds should be sown thinly and watered sparingly. Sow early
in April, and transplant in the middle or end of May in rich soil.
Water occasionally with weak liquid manure.
Gesneria.--Handsome greenhouse perennials. They thrive in any light,
rich soil. Cuttings will strike readily either in sand or soil if
placed under glass in heat. They may also be raised from seed sown in
a temperature of 75 degrees in March or April. They flower in October.