This section is from the book "The Gardener's Monthly And Horticulturist V24", by Thomas Meehan. See also: Four-Season Harvest: Organic Vegetables from Your Home Garden All Year Long.
The Nerium, commonly called the Oleander, is a much neglected though a very beautiful plant. It is an erect-growing, evergreen shrub, of the easiest culture, abundant in flower, exquisite in fragrance. They flower freely when scarcely a foot high, but will attain a height of ten or twelve feet. Hardy along the gulf coast.
To bloom them in perfection they need a stove, and yet do well in the parlor and out of doors, budding out finely. In potting give plenty of pot room, and use a soil composed of equal parts of loam, well rotted manure, and peat or leaf-mould.
One way to manage these plants is to let them have a short rest after the summer flowering, which can be effected by drying. Then trim to within a few eyes of the previous year's wood, having due regard to the symmetry of the plant, and place in a warm greenhouse, encouraging them to make a short growth before winter sets in. In the spring shift into above compost, and stop the young growth so far as necessary to make good heads. If not convenient to shift as the plant grows, give liquid manure.
Another system is to pot in spring as above; and if any of the plants have bad heads cut them down to the shape desired. The old wood will push new shoots. Keep the plants thus headed down until May, when they may be planted in the garden ; or if that cannot be done, turn them out, reduce the ball of earth by probing with a pointed stick all around the sides and bottom of the ball, cutting off any very matted roots. If any of the roots are decayed cut them into the sound wood. Re-pot into same tub, filling in with fresh compost, and give very little water unless there are signs of vegetation.
These plants may also be re-potted in August,; and as they are of a strong habit will not be injured thereby, and that is a convenient season to do the work, as it is out of doors. They may be wintered in the house or in a light cellar, and should then be but slightly watered; during the growing and blooming seasons, however, they should have plenty of water. Cuttings strike root with great ease if kept moist.
Neriums are generally seen, when blooming, with as much growth above the flowers as below them; this is the result of neglect. Soon after the trusses of bloom show themselves, young growths of wood start from the base, and if these are allowed to remain, the flowers are weakened and hidden. Pick them out as soon as seen, and the flowers will form beautiful heads above the foliage.
Flower buds frequently form late in the fall, lie dormant all winter, whilst the foliage and branches continue to grow, and in the spring expand into full-blown flowers, which then appear stuck in the midst of leaves, with branches all around them.
These plants are frequently infested with white scale. For that, scrub stems and wipe leaves with a strong decoction of tobacco, heated to about 100°, and clean afterwards with soap and water; or, with a whisk broom sprinkle thoroughly with Paris green prepared in water, as for potato bug, repeating several times through the summer.
It must be noted that the wood, bark and leaves of this plant are all poisonous. Death has resulted from eating meat in which skewers of Oleander wood have been used; the powdered bark is used as a rat poison, and an infusion of the leaves is a powerful insecticide.
The principal varieties described are Nerium oleander, the common rose-colored single-flowering species, from which many varieties have originated ; N. 0. splendens, the most popular, a double rose colored flower; N. O. striata fl. pl., with double flowers, striped rose and white; N. album maximum, semi-double, white ; N. grand-iriorum plenum, double rose ; Shaw's seedling, deep crimson, single; N. macrophyllum, very double and large, deep pink; N. album plenum, double white; N. atropurpureum plenum, dark purple, rich ; N. cardinale, double rich purple vermilion, lighter in centre of petals, very fine. N. flavum duplex, double yellow, fine and distinct ; Geant des Battailles, single, light blue centre, petals edged with crimson, very fine; N. madoni grandiflorum, double white, free flower ing. fine ; Professor Durand, fine double yellow ; N. 0. Eleganti ssimum, a most beautiful plant with deep, silver-edged foliage, and young wood, striped white and green; and many other fine varieties. The writer, however, doubts whether there is such a thing as a truly double white, or a true yellow.