The most useful species of bougain-villea is the well known glabra, which makes a fine greenhouse climber in any house where the temperature does not go below 50 degrees at night. The flower is inconspicuous; it is the showy, rosy-purple bracts of the flowers that give the plants such an ornamental appearance. Long sprays of the bougain-villea covered with these showy bracts are of great value for decorations.
The plant should be in a large pot or tub, or may be planted out in the border, but where it has unlimited root room it grows too freely and does not flower so well. During winter the supply of water can be diminished till the plants start growing again, in March, at which time the plants can be cut back to within a few eyes of the previous year's growth.
The variety of B. glabra known as Sanderiana begins to flower when very small and is much the best for plants of medium size in pots. We were very successful in flowering plants of this the past spring but are disappointed in it as a house plant. The great majority of our flowering plants are sold to people who want them for their windows or rooms and unless a plant has fair keeping qualities under such conditions it will never be popular. The bracts of B. Sanderiana, while hanging on the plants for months in the greenhouse, soon drop with the leaves when removed to the dry heat of the living-room.
The cuttings of half ripened wood root readily in March, April or May. In the former two months, bottom heat is needed. The cuttings should be of strong growth, five or six inches long. Keep the sand moderately moist and little shade is required. They take about three weeks to root. Pot carefully and spray frequently, but do not keep the soil very wet. They will soon start to grow and should be given the full light under glass, with copious waterings and daily syringing. By September they should be in 6-inch pots. In October they will begin to ripen their growth and as the temperature gets cooler less water must be given. This is their resting time.
The bougainvilleas are now a great Easter plant, but by starting them at intervals they can be had in flower from January on. If kept cool the bracts will hang on for months. In June they can be cut back, some worn-out soil reduced from the old ball, and started growing again. After they are once in 4-inch pots they should be well drained, for although they want copious watering when growing fast, stagnant water at the roots would be most injurious to them. The bougainvillea is a tropical plant, but in November, December and January, while slightly resting and with less water, it will do very well in a temperature of 50 degrees. When started into active growth it should have 60 to 65 degrees. A good, friable loam with the addition of some sand and leaf-mold will suit it well. In large pots the loam should be merely chopped. Soft wood cuttings of this plant root easily and in June can be planted out in some good, rich loam and will lift before cold weather and, with a few months' rest, will flower in spring. But these plants will not be as large as those from the strong cuttings and grown entirely under glass.