Hibiscus Africanus.—­A handsome hardy annual Mallow.  Sow in March in slight heat, and plant out in May 10 in. apart.  Grows best in a mixture of loam and peat.  Blooms in June.  Height, 2 ft.

Hibiscus Syriacus (Rose of Sharon).—­A hardy, deciduous, autumn-flowering shrub, which will grow in common soil, and may be propagated by seeds, layers, or cuttings planted under glass.  Height, 6 ft.

Hieracium (Hawkweed).—­A free-growing hardy perennial, suitable for a sunny bank or border.  It is not particular as to soil.  From June to September it produces orange-brown flowers.  It grows freely from seed, and the roots bear division.  Height, 1-1/2 ft.

Hippeastrums.—­See “Amaryllis.”

Hippocrepis.—­Very pretty hardy trailing perennials, covered from May to July with golden Pea-shaped flowers.  They will grow in any light, sandy soil, and may be increased by cuttings, which root readily under glass.  Height, 3 in. to 6 in.

Hippophae.—­Ornamental shrubs, thriving in ordinary soil, and increased by layers or cuttings of the roots.  H. Rhamnoides (Sea Buckthorn) flowers in May.  Height, 12 ft.

Holboellia Latifolia.—­See “Stauntonia Latifolia.”

Holly (Ilex).—­This pleasing hardy evergreen shrub thrives best on a deep, sandy loam, but will grow in any good soil, provided the position is dry.  It succeeds well in the shade.  Cuttings of young shoots having 1 in. of the old wood attached will strike root, but the plant is of very slow growth, and takes at least four years to grow into a good bush.  Choice varieties may be grafted or budded on to the common sorts in June or July.  To grow Holly from seed, gather the berries when ripe, crush them, and mix them up with a little sandy loam, bury them in a hole 3 ft. deep, and cover with litter.  Dig them up and sow them in March.  Big bushes are best moved at the end of August, mixing the earth to a puddle before planting.  The less pruning they receive the better.  They may be trimmed in spring.

Hollyhock.—­May be raised from seed or cuttings.  Sow the seed about the second week of March in very rich soil, and cover it with 1 in. of dry earth.  In June (having soaked the bed thoroughly overnight) remove the young plants to a nursery-bed, setting them 6 in. apart.  Press the earth firmly round the roots, and water plentifully until settled.  In the autumn plant them where they are to bloom.  Cuttings may be taken as soon as the flowers appear, or from the old plants in autumn.  Each joint having an eye will furnish a plant.  Select side branches having two or three joints and leaves.  Cut the shoots through just under the lower joint, leaving the leaf entire; cut it also about 2 in. above the joint.  Plant in equal parts of loam, gritty sand, and leaf-mould; shelter from the sun, and sprinkle them every day in fine weather with water.  If the cuttings are taken in autumn pot them off in 60-sized pots, and keep them in a cold frame till the spring, when they may be planted out.  Flowers in August.  Height, 6 ft.