Part 25

Hovea Celsi.--A greenhouse shrub, which is evergreen and elegant when in flower in June. A sandy loam and peat soil is most suitable, and it may be increased by cuttings planted in sand under a hand-glass. Height, 3 ft.

Humea.--A remarkably handsome and graceful plant, the leaves of which when slightly bruised yield a strong odour. It is equally suitable for the centre of beds or large borders, and placed in pots on terraces or the lawn it is very effective. The seed should be raised on a gentle hotbed, then potted off and kept in the greenhouse till the second year, when it may be turned out into a warm situation. It generally succeeds better in such a position than in the greenhouse. Flowers in July. Height, 6 ft. to 8 ft.

Humulus Japonicus.--(Japanese Hop).--A hardy annual Hop of rapid growth, the leaves of which are splashed with white. Useful for covering arbours, verandahs, etc. A deep, loamy soil suits it best. Increased by seed sown in gentle heat in February, and gradually hardened off. Flowers in July. Height, 20 ft.

Hutchinsia Alpina.--This small alpine creeper is a profuse bloomer, its glistening white flowers being produced at all seasons. It grows in moist vegetable mould, and bears transplanting at any season. Care, however, is required to prevent its roots over-running and choking other things. Height, 2 in.

Hyacinths.--May be grown in pots, in glasses, or in beds and borders. The soil should be rich and light. Good loam mixed with old manure and a little leaf-mould and sand suits them very well. If intended to be grown in pots the best time to begin potting is early in September, putting more in at intervals of two or three weeks until the end of December. One bulb is sufficient for a 5-in. or 6-in. pot, or three may be placed in an 8-in. pot. The soil under the bulb should not be pressed down. The top of the bulb should be just above the surface. Place the pots on a bed of ashes in a cold frame, put a small inverted pot over the top of the bulb, and cover the whole with cocoa-nut fibre or cinder-ashes to the depth of about 4 in. In about a month roots will have formed with about 1 in. of top growth. The plants may then be taken out, gradually exposed to the light, and finally removed to the conservatory or sunny window. The doubles do best in pots.

For growing in glasses select the firmest and best-shaped bulbs. Those with single blossoms are preferable, as they are of stronger constitution than the doubles. Fill the glasses with pure pond or rain water, so that the bulbs just escape touching it, and put a piece of charcoal in each glass, and change the water when it becomes offensive, taking care that the temperature is not below that which is poured away. Stand the glasses in a cool, dark place for three or four weeks until the roots have made considerable progress, then gradually inure to the full light. September is a good time to start the growth.

When planted in beds or borders, place the bulbs about 4 in. deep and 6 in. apart, putting a little silver sand below each one. This may be done at any time from October till frost sets in. They succeed fairly well in any good garden soil, but give greatest satisfaction when the ground is rich and light.

Hyacinthus (Muscari).--A very hardy race of spring-flowering bulbs. Though the varieties are very dissimilar in appearance, they all produce a good effect, especially when planted in good large clumps. Plant from September to December. A sandy soil suits them best. The following are well-known varieties:--BOTRYOIDES (Grape Hyacinth).--Very pretty and hardy, bearing fine spikes of deep, rich blue flowers in compact clusters on a stem 6 to 9 in. high. Sweet-scented, and blooms about May. The Alba, or white, variety is also sweet-scented.

Hyacinthus--continued.

CANDICANS (Galtonia).--The white Cape Hyacinth, or Spire Lily. A hardy, summer-flowering, bulbous plant 3 ft. to 4 ft. in height, gracefully surmounted with from twenty to fifty pendent, bell-shaped snow-white flowers. Thrives in any position and equally suitable for indoor or outdoor decoration.

MOSCHATUS (Musk Hyacinth).--Bears very fragrant purplish flowers.

PLVMOSUM (Feather Hyacinth).--A fine, hardy, dwarf plant suitable for any soil. Its massive sprays of fine blue flowers, arranged in curious clusters, 5 to 6 in. in length, resemble much-branched slender coral.

RACEMOSUM (Starch Hyacinth).--Rich dark-blue or reddish-purple flowers. Very free-flowering and fine for massing. It is similar to the Cape Hyacinth, but flowers in denser spikes.

Hydrangea.--This shrub delights in a moist, sheltered position and rich soil. It may be increased at any time from cuttings of the young side-shoots, 2 or 3 in. long, under glass, in sandy soil. The old stems will also strike if planted in a sheltered situation. The plants should be cut back when they have done flowering, and protected from frost; or they may be cut down to the root and covered with manure. They are well suited for the front of shrubberies, and also make fine plants for pot cultivation. The flowers are produced in June and July. Height, 3 ft.

Hymenanthera Crassifolia.--Ornamental evergreen shrubs, thriving best in a compost of loam and peat. They are increased by cuttings planted in sand and subjected to a little heat. Height, 6 ft.

Hymenoxys.--Pretty little hardy annuals that may be easily raised from seed sown early in March in any garden soil. They bloom in June. Height, 1 ft.

Hypericum (St. John's Wort).--Favourite dwarf shrubs. Any soil suits the hardy kinds, but they prefer shade and moisture. These may be increased by seed or division. The greenhouse varieties thrive best in a mixture of loam and peat. Young cuttings placed in sand under glass will strike. July is their flowering season. Height, 1-1/2 ft. to 2 ft.

Iberis.--See "Candytuft."

Ice Plants.--See "Mesembryanthemum."

Ilex.--See "Holly."

Impatiens Sultani.--Half-hardy perennials. May be raised from seed sown early in spring on a hotbed, or later on in a shady spot in the open border; greenhouse culture, however, is more suitable. They bloom in August. Height, 11/2 ft.

Incarvilleas.--Ornamental hardy herbaceous plants, of easy culture. They are suitable for the border or the rockery, and will grow in any soil if not too dry and exposed. The tuberous roots may be planted at any time in autumn, 4 in. deep. I. Delavayi makes a fine solitary or lawn plant, its leaves being from 1 to 3 ft. long; the soft rose-pink, Mimulus-shaped flowers, which are carried on stout stems well above the foliage, appearing in May. Care should be taken not to disturb it in spring, and it is advisable to cover the roots in winter with a pyramid of ashes, which may be carefully removed at the end of April. Incarvilleas may be propagated by seed sown, as soon as it is ripe, in light, well-drained soil, giving the young plants protection in a frame during the first winter, with enough water merely to keep them moist. Height, 2 ft.

Indian Corn.--See "Zea."

Indian Shot.--See "Canna."

India-rubber Plants.--See "Ficus."

Indigofera.--Beautiful evergreen shrubs. I. Australis has elegant, fern-like foliage and racemes of pink or purple Pea-shaped flowers in April. I. Decora Alba bears its white flowers in July. They require a sandy loam or peat soil, and greenhouse culture. Cuttings of the young wood planted in sand under glass will strike. Height, 21/2 ft.

Insects on Plants.--To destroy insects on plants wash the plant with Tobacco-Water (which see). Or put 1 oz. of quassia chips in a muslin bag, pour on some boiling water, and make it up to I gallon; dissolve 1 oz. of soft soap, add it to the chips, and stir well. Use it two or three times during spring and early summer.

Inula Royleana (Fleabane).--A hardy perennial which flowers in November. It will grow in any garden soil, and can be increased by seeds, or by division of the roots. Height, 3 ft.