Gynerium (_Pampas Grass_).--This unquestionably is the grandest of all grasses, and is sufficiently hardy to endure most of our winters. It is, however, desirable to give it some protection. It requires a deep, rich, alluvial soil, with plenty of room and a good supply of water. Plants may be raised from seed sown thinly in pots during February or March, barely covering it with very fine soil, and keeping the surface damp. Plant out at end of May. They will flower when three or four years old. The old leaves should be allowed to remain on till the new ones appear, as they afford protection to the plant. It may be increased by division of the root. Height, 7 ft. Gypsophila.--Of value for table bouquets, etc. They will grow in any soil, but prefer a chalky one. The herbaceous kinds are increased by cuttings; the annuals are sown in the open either in autumn or spring. They bloom during July and August. Height, 1 ft. to 3 ft. H Habrothamnus.--These beautiful evergreen shrubs require greenhouse culture, and to be grown in sandy loam and leaf-mould. The majority of them flower in spring. Height, 4 ft. to 6 ft. Halesia Tetraptera (_Snowdrop Tree_).--This elegant shrub will grow in any soil, and may be propagated by cuttings of the roots or by layers. The pendent white flowers are produced close to the branches in June. Height, 8 ft. Hamamelis (_Witch Hazel_).--An ornamental shrub which will grow in ordinary soil, but thrives best in a sandy one. It is increased by layers. May is its season for flowering. Height, 12 ft. to 15 ft. H. Arborea is a curious small tree, producing brownish-yellow flowers in mid-winter. Harpalium Rigidum.--A hardy perennial, producing very fine yellow flowers in the autumn. It will grow in any good garden soil, and may be propagated by seed sown in early autumn, or by division of the roots. Height, 3 ft. Hawkweed.--_See_ "Crepis" _and_ "Hieracium." Heartsease.--_See_ "Pansies." Heaths, Greenhouse.--For their successful growth Heaths require a well-drained soil, composed of three parts finely pulverised peat and one part silver sand, free ventilation, and a careful supply of water, so that the soil is always damp. If they suffer a check they are hard to bring round, especially the hard-wooded kinds. Some of the soft-wooded Heaths, such as the H. Hyemalis, are easier of management. After they have flowered they may be cut hard back, re-potted, and supplied with liquid manure. The stout shoots thus obtained will bloom the following season. (_See also_ "Ericas.") Hedera.--_See_ "Ivy."