Colorful Summer and Winter-flowering Shrubs That Are Easy to Grow
The Buddleias (Buddlei’a) are beautiful flowering shrubs of vigorous growth, which are found wild in northern Asia, South America and South Africa and belong to the family Loganiaceae. Some are hardy; others are suitable only for planting out of doors in mild districts. Most are deciduous or leaf-losing. The name Buddleia commemorates the Reverend Adam Buddle, a vicar of Farnbridge, England; his collection of dried plants is preserved in the British Museum.
When to Plant
Buddleias. grow well in ordinary garden soil, which has been dug deeply and well manured. In rich, deep, loamy ground the plants make exceptionally free growth and produce a profusion of flowers. Planting may be done in spring or fall.
Prune These in Spring
Correct pruning is of great importance. Those kinds which flower in late summer and autumn, notably the varieties of Buddleia Davidii (variabilis), should be pruned hard each year in spring; the shoots of the previous summer’s growth are cut back to within 2 or 3 in. of the older wood; if it is desired to increase the size of the bushes rapidly, the new shoots are left 6-9 in. long, but all thin, weak twigs are cut out. In severe climates the growths may be killed to the ground in winter but as long as the roots survive, new shoots are produced that bloom the same summer. Most of the Buddleias produce their flowers, like the foregoing, on the new shoots of the year but there are notable exceptions.
Prune These After Flowering
Buddleia alternifolia is a leaf-losing kind which produces its flowers on the older wood, and the evergreen, or semievergreen, Buddleia globosa, and B. Colvillei also bear blooms on the year-old branches. Therefore, so that all the flower buds shall be preserved, these kinds must not be pruned until flowering has finished. As this is not until June only a small amount of thinning and cutting out of the old branches is possible at this late date, though a few exceptionally long shoots may be shortened. If in five, six or more years the bushes become tall and ungainly, all of these Buddleias should be cut hard back into the old wood in early April; one season’s flowers will be sacrificed, but fresh vigorous shoots will develop.
Seedlings Bloom in Eight Months
Seeds and cuttings provide ready means of propagating Buddleias; these are among the quickest shrubs to flower from seeds. Seeds are sown thinly during February or March in pots or pans filled with sandy soil and placed in a greenhouse—temperature 50 degrees. Seedlings of Buddleia Davidii, raised in a heated greenhouse in February, will flower within seven or eight months.
When to Take Cuttings
Named varieties must be increased by means of cuttings. Two types of
cuttings can be made. Those of half-ripe or semiwoody side shoots, 5 or 6 in. long, are inserted in a cold frame kept close, or out of doors under a hand light, during July and early August. Cuttings made of the mature shoots of the year, 12-18 in. long, are taken off with a thin “heel” of old wood at the base and inserted in a sheltered border out of doors or in a frame in late September or October.
The Favorite Buddleias
The most useful Buddleias are the numerous varieties of B. Davidii, previously called B. variabilis, a shrub from central and western China. The bushes can be kept to a height of 6-10 ft. by hard pruning each year in early spring, in the way explained, or in mild climates they will grow 20 ft. or more high if pruned less severely. The deciduous leaves are lanceolate, 10-12 in. long, white or grayish on the undersides. The honey-scented, lilac-mauve, purple, pink, red, and white flowers with orange-yellow centers are borne freely from July to October.
Of the numerous varieties of B. Davidii, the best include Veitchiana, mauve flowers with orange eye; magnifica, deep rose-purple flowers, with reflexed corolla lobes, and orange eye; Wilsonii, drooping or arching spikes of rose-lilac flowers; nanhoensis, a dwarf variety from Kansu of spreading habit, 3-4 ft. high, with smaller leaves and smaller inflorescences of mauve flowers. In addition, there is a group of new garden varieties in a wider and finer color range than older types. These include the varieties Fascinating, Fortune, Peace, Purple Prince, White Profusion and Flaming Violet.
When B. Davidii is raised from seeds the panicles vary in size, and the flowers in color. On sunny days they prove a great attraction to bees and butterflies, which are evidently drawn by the honey scent of the flowers. Buddleia Davidii is a valuable shrub for town and suburban gardens, and is also a good seaside shrub.
The Weeping Willow Buddleia
B. alternifolia is a very hardy and very graceful Chinese kind, 10 ft. or more high, with pale-purple or mauve flowers clustered along the slender shoots of the previous year’s growth in June. It is particularly attractive when trained as a standard.
Buddleia globosa, the Orange Ball Tree of Chile and Peru, is evergreen or semievergreen, 8-12 or 15 ft. high, with lance shaped leaves, dark green above and tawny yellow beneath. The sprays of fragrant, ball-shaped, orange-yellow flower heads are borne in May and June. This species is suited for planting outdoors only in mild climates such as that of California.
Suitable, too, for such climates only is Buddleia Colvillei, a vigorous Himalayan shrub that will reach a height of 30-40 ft. and bears attractive rose-colored flowers in May and June. Buddleia asiatica, a native of southeastern China and India, is a very useful winter-flowering greenhouse plant that can only be grown out of doors in the South. The slender arching panicles of white flowers are fragrant. B. Farquhari, a hybrid between B. officinalis and B. asiatica, has pale lavender-pink flowers. It blooms in winter and has the same uses as B. asiatica.
Buddleia officinalis, a native of central and western China, is another kind that is suitable only for planting out of doors in warm localities. It is a handsome shrub of vigorous growth with spikes of pale lilac flowers with orange eyes; its flowers open in April out of doors, earlier under glass.
Other Buddleias worthy of cultivation in southern gardens are B. crispa, B. madagascariensis and B. salvifolia.
Buddleias for Greenhouse Cultivation. Buddleia asiatica and B. Farquhari are sometimes grown in cool, airy greenhouses for flowering during January and February. These Buddleias form handsome specimens when cultivated in large pots or tubs, and are useful for decorating spacious conservatories and for the production of flowers for cutting. As generally grown, the plants are 5-8 ft. high when in bloom, but old specimens may be considerably higher.
The plants may be kept growing for several years but it is usually more convenient to propagate new ones each season and discard the old ones, except those needed for the production of shoots to make cuttings of. The cuttings are taken as soon as the plants are through flowering.
Cuttings of young shoots, 3-4 in. long, are severed just beneath a joint or node with a sharp knife, and their lower leaves are removed. They root readily in a propagating bench containing sand or vermiculite. The cuttings may be made and inserted from March to May. After insertion they should be shaded from strong sun and protected from drafts. As soon as they have roots 1-2 in. long, the young plants are potted individually in 21/2-in. or 3-in. pots in sandy soil. Following potting, they are shaded lightly for a few days, then exposed to full sun in a freely ventilated greenhouse where the night temperature is 45-50 degrees and the daytime temperature 5-10 degrees higher.
When their first pots are filled with roots, the plants are transferred to larger pots, containers 4-5 in. in diameter being suitable for the second potting. At this potting and later ones a rich, loamy soil should be used. A good mixture is: 2 parts of good loam (topsoil), 1 part of peat moss or leaf mold, 1 part of coarse sand, 1/2 part of dried cow manure, and bone meal at the rate of 1 pint to each bushel of the mixture.
The plants are potted successively in larger pots until August or September, when the last potting is done. Final pots for first-year plants may be 7-10 in. in diameter; plants more than 1 year old will need larger containers.
In order to promote branching and ensure bushy specimens it is necessary to pinch the ends of the shoots occasionally. The first pinch should be given as soon as the young plants are well established in their first pots, the last pinch not later than early September.
The plants should be staked and tied neatly, and watered freely from the time of their propagation until they are through flowering (cutback plants that are retained to supply cuttings should be kept somewhat drier). They should be fertilized frequently with dilute liquid fertilizers throughout their growing season. During the summer they may be stood, in their pots or tubs, in a sunny place outdoors or may be kept in the greenhouse; if put outdoors they must be brought inside before frost comes.
If specimens are to be grown for more than one year they should be cut back lightly after flowering and kept in a cool, airy greenhouse, and given only moderate supplies of water, until March. Then they should be pruned to shape, be repotted or top-dressed, and watered and syringed more freely to encourage them to start into strong new growth.