Mostly evergreen shrubs, chiefly from tropical America, belonging to the Pea family, Leguminosae. They grow from 6-50 ft. in height, have pinnate, dark green, glossy leaves, and bear golden-yellow flowers in terminal clusters in summer. Cassia is from the original Greek name Kasia.
Most Cassias are hardy outdoors in the far South only. There they grow freely in light, well-drained soil in full sun. Some kinds, especially Cassia corymbose, a South American kind, are suitable for growing in cool, sunny greenhouses. Others useful for this purpose are Cassia glauca, a native of tropical Asia and Cassia splendida from Brazil.
Under greenhouse cultivation, a minimum winter temperature of 50 degrees is required. The best compost consists of equal parts of peat and loam with sand added. In February, the lateral or side shoots on the main branches are cut back to within three buds of the base of the past summer’s growth, and the leading shoots—those at the ends of the main branches—are shortened by half. They are syringed frequently until the shoots break into growth, and are then repotted in larger pots. When established, cooler conditions are maintained and they are exposed to full sunlight to ripen the growth for flower production in summer.
Propagation is by shoots inserted in pots of sandy peat in March. They are placed in a propagating case in a heated greenhouse and when rooted are potted in 3-in. pots, being transferred later on to 5-in. pots in which they produce flowers the following summer. To ensure bushy, well-branched plants the main shoots are pruned back to three or four buds and the side shoots are treated similarly. The plants need abundance of water during the summer when growth is vigorous, but little from
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