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 genus Allamanda embraces some of our most desirable as well as some of our most showy stove plants. Of this splendid genua A. nerifolia is deserving of a prominent place in all collections of stove and greenhouse plants on account of its free flowering qualities.
This handsome species attains a height of five or six feet, and is of compact bushy habit, producing its bright yellow flowers in the greatest profusion for at least nine months in the year if kept in a healthy and growing condition. On account of its floriferous habit it is unequalled as a plant for decorative purposes, while as an exhibition plant this Allamanda is excelled by none.
The flowers of this species are small in size when compared with others of the genus, but I do not consider this much of an objection when we take into consideration the immense number of flowers which it produces.
Whether grown in the greenhouse or plunged in the flower border, it is equally at home, flowering in profusion in both places. This Allamanda is a plant of very free erect growth ; it is perfectly free from all insect pests, and is moreover a plant of comparatively easy culture providing it can be given sufficient heat during the winter season, say a temperature of from 50° to 60°. It requires a compost of two-thirds fibrous loam, one-third thoroughly decomposed manure and a little sand to render the compost a porous and open one; give good drainage, and if large specimens are wanted do not permit the plants to become pot-bound. When growing, water freely and syringe occasionally, while an occasional watering of liquid manure water will prove to be very beneficial. This Allamanda can be plunged in the flower border about the middle of May and taken up about the middle of September. The plant should be repotted before being plunged. It is an essential point in the cultivation of this plant in the open air to keep it at all times abundantly supplied with water.
Propagation is effected by cuttings of the young shoots which root easily during the summer months, and if the young plants are liberally treated, and kept in a growing condition will produce fine specimens in the course of a few years. With me this Allamanda occasionally ripens seed, but I have never tried to raise plants from them.