The bouvardia can be classed as almost a tropical plant, most of the species coming from southern Mexico and South America. The hybrids of some of these species are what are of value to the florist. Twenty years ago the bouvardia was one of the most important of the plants we grew, but of late years, with the advent of the long-stemmed carnations, the wonderful roses, the chrysanthemum and other more durable flowers, the bouvardias have been much less grown, and in commercial places they generally occupy but a small place, if any, notwithstanding they are beautiful and easily grown, and that the flower has grace and refinement. In these days of keen competition, the question is, "Do they pay?" That you must judge by experience in your own locality.
The best time to begin propagation is early March, with the roots of plants that have been grown on a bench for winter flowering. The bouvardia roots very slowly and unsatisfactorily from the young top growths, and in ordinary practice that is not considered a practical method of propagating this plant. We will begin with the roots. Don't take the large roots near the base of the plants, nor the thin, thread-like roots of the widest growth. Choose the growths between these. Cut them into pieces about one-half or three-fourths of an inch in length and distribute them on a propagating bench, where you have a good heat, as you would coarse seed, pressing them into the sand. Then cover with at least an eighth of an inch of sand, pressing it down after covering. Water sufficiently to keep moist, about as you would other cuttings. In three or four weeks young plants will be springing up. When they have made two or three leaves and are an inch high, lift them from the sand and pot into 2-inch pots.
The bouvardia is a tropical plant and at no stage of its existence should it be exposed to a low temperature. This accounts for the very different treatment we give it from what is considered right in western Europe. Plant out in the open ground about the first of June, or earlier, if you are in a latitude where no late frosts appear. A very light, rich soil is much the best adapted to the wants of the bouvardia. Unless there is a very long spell of hot, dry weather, no watering is needed after the first good watering when planted. The growth that has started in the greenhouse will continue to grow out of doors, but that is of little consequence, and can before lifting be entirely cut away. It is the strong, vigorous growth that will spring from the roots after being planted out that you will depend on to give you flowers. They want stopping about twice during the summer.
The lifting time will vary according to where you are. In Buffalo we used to lift about the second week in September. If later, and the weather should be cold, they are much slower in taking hold of the soil in their new quarters. A very good plan is to do the last pinching a week or so before you lift them. The break from this last stopping will then come in. about right for the holidays. Plant in five inches of good loam, and as to distance apart, be guided by size of the plants. A foot apart is little enough for any of them. Anybody, with almost any temperature, can get the first crop of bouvardia, but to get them to make a growth and a profitable crop of flowers again in March requires heat. Unless they are kept in a night temperature of at least 60 degrees and syringed daily, they will just stand still after their first crop is over. The rampant way they grow and flower when the warm sun of April comes shows you what they want.
They can, of course, be grown in pots, but do far better and are more easy to manage planted on a bench in a light, warm house.
If at the end of March you need the bench for some other crop you can cut down the bouvardias to within a few inches of the bench, lift them, shaking off all the soil, and place them close together in flats with three or four inches of moist soil around them, and put under a bench where there is not much drip, and they will do there all right till planting out time. The old plants will of course be much larger than those propagated the first year.
Red spider attacks them and so does mealy bug, but their presence is inexcusable, for a proper use of the hose will prevent both. Greenfly will appear if fumigation is neglected, but be careful to smoke lightly, particularly when the plants are first housed, for they burn readily.
In lifting I cannot say as you can about carnations, "Let all the soil tumble off if it will, so long as I save every fiber," for they do not lift so well, or rather do not recuperate so quickly. Lift carefully with a good ball of earth and for the first week shade and syringe frequently. The bouvardia is worth the care it requires, for if well grown the price realized is usually satisfactory.