Clerodendrum - Glory Bower
DESCRIPTION: This is a large group of deciduous (leaf losing) and evergreen trees and shrubs, including many woody climbers. Most of them grow wild in tropical and subtropical countries, therefore, to grow them successfully in cool climates they must be cultivated in greenhouses having a minimum winter temperature of 60º F. More than a hundred species have been discovered, but only a few are in cultivation. The name is from the Greek kleros, chance, and dendron, a tree, and alludes to a native legend that the trees possessed medicinal properties, which were a possible cure for certain ailments. Clerodendrums, commonly known as Glory Bowers, are grown for their pretty flowers and attractive, opposite leaves. Glory Bowers are found wild in four of the five continents, the exception being Europe. C. Thomsoniae, from tropical Africa, and its variety delectum are the most popular of the climbing Clerodendrums. They bloom profusely throughout the summer and autumn and can grow 10-15 feet high. C. Thomsoniae's leaves are ovate and glossy and its flowers are white and red; its variety, delectum, has very large clusters of flowers colored a lighter shade of red. C. splendens, from Sierra Leone, is a climbing plant that bears scarlet flowers from June to September. C. umbellatum (C. scandens) from South Africa, will thrive in a greenhouse that has a minimum winter temperature of 45º F. The white flowers, marked with red, open in July and August. The most popular of the shrubby, greenhouse varieties is C. speciosissimum. This is an erect bush that flourishes in warm, humid conditions. The large panicles of flowers are produced throughout the summer. It's a native of Java. It is easily propagated by seeds and cuttings. C. fragrans is a bush that grows 2-6 feet high. In late summer and fall it produces terminal corymbs of fragrant, white flowers. C. infortunatum is a great shrub to decorate the warm greenhouse. It grows 5-6 feet high and bears sweet-scented white flowers with red centers. It's a native of India, Ceylon and Malaya. C. myrmecophilum, native of Singapore, is one of the most beautiful kinds for growing in pots in a warm greenhouse. It grows 2-3 feet high, has huge leaves and lovely red and yellow flowers. C. trichotomum is a hardy, erect shrub or small tree that can grow, in favorable conditions, 20-25 feet high. This native of eastern China and Japan has large, ovate, fuzzy leaves that give off a slightly unpleasant odor when crushed. The fragrant white flowers each have a maroon calyx and are produced in late summer. The red calyces and blue fruits are noticeable in the fall. C. Bungei isn't as hardy as C. trichotomum, but it can survive further north than the tropical kinds. This suckering shrub makes a thicket of dark-colored stems, which may reach a height of 4-6 feet, and are covered with large, heart-shaped leaves. From late summer to early fall, clusters of fragrant, rosy-red flowers are borne. This plant is suitable for growing in the shade of large trees or shrubs. Although the flowers have a sweet scent, the leaves emit an unpleasant odor when bruised. It may be necessary to cut this shrub to the ground after a harsh winter.
POTTING: These plants can be grown in sun or shade in any well-drained, friable soil. Site your plant carefully in a sheltered location. In climates where winters are harsh, Clerodendrums may be grown in a greenhouse in containers filled with two-thirds fibrous loam, and one-third leaf mold and peat. Sand, wood ash and a bit of bone meal should be added. The climbing kinds do better when planted in a bed of soil rather than in pots or tubs. They should be trained to pillars and rafters to show off their full beauty. They need an annual top-dressing of fresh compost. If they are grown in large pots or tubs, they may be trained around stakes or wires fashioned into the shape of a balloon. During the spring or summer, you should sprits the plants on sunny days. This encourages fresh growth and keeps them free from pests. It's usually necessary to spray with an insecticide every ten days or so during the growing season. When they are grown in a greenhouse, they will benefit from large amounts of liquid fertilizer from April to August. Those grown in a greenhouse also need a resting season during the winter by reducing the water considerably and by lowering the temperature and humidity. Pruning consists of removing the dead twigs on old bushes in the summer. When grown outdoors, there are usually dead ends of branches to cut off following a severe winter.
PROPAGATION: Following the hard pruning of the previous year's growths in early spring, the plants soon make new growth in a warm, moist atmosphere. Fresh shoots, 2-4 inches long, can be inserted as cuttings in a propagating case. Cuttings that are made from the shoots of the current year, 3-6 inches long, may also be inserted in a propagating case or under a bell jar in August. Seeds may be sown in a greenhouse or closed frame in early spring. Root cuttings can be placed in a closed frame in early spring and suckers can also be detached and potted.
Hothouse vines: C. Thomsoniae & var. delectum; C. splendens; C. umbellatum (C. scandens).
Greenhouse shrubs: C. speciosissimum; C. fragrans & var. pleniflorum; C. infortunatum; C. myrmecophilum; C. Bakeri.
Outdoor: C. trichotomum & var. Fargesii; C. Bungei. C. verbenaceae. C quadriloculare.
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