DESCRIPTION: These are gorgeous, herbaceous plants that climb. They bloom in the evening and are related to the Morning Glory. They grow wild in the tropics of both hemispheres. C. aculeatum is the most common kind. It can reach a height of 15 feet or more. It's covered with lovely leaves and white, fragrant flowers that resemble trumpets, up to 6 inches across. Calonyctions (Moonflowers) are able to thrive as perennials outside in the far South only. Otherwise, they may be grown in greenhouses, or started early inside and transferred outdoors later to live as summer annuals.
POTTING: Those grown in a greenhouse need a minimum winter temperature of 45 degrees. They can be planted in large pots or tubs or a prepared bed of soil. The soil mixture to use should consist of two parts loam, one part peat moss or leaf mold, and one part of well-decayed manure with a liberal amount of sand added. The shoots should be trained to a trellis or wires that are attached to the roof or wall of the greenhouse. In the early spring, the soil should be top-dressed with rich compost and wiry shoots are cut out to prevent the plant from becoming crowded. Water should be given abundantly from April to September and liquid fertilizer should be applied once in a while if necessary; the remainder of the year, water sparingly, only when the soil is dry.
PROPAGATION: The greenhouse kinds may be propagated by sowing seeds in pots of sandy soil in the spring, or by cuttings inserted in a propagating case at the same time, or by layering the shoots in the summer. When planting outside, seeds can be sown where they are to bloom, in regular garden soil. There should be wires, strings, trellis, etc. for the shoots to climb upon. Faster results may be had, by planting 2 or 3 seeds in small pots filled with sandy soil. Place them in a greenhouse that has a 55-degree temperature in March. The seeds are more guaranteed to sprout if a notch is cut through the skin of each before sowing. The baby plants may be placed outside in May.
VARIETIES: C. grandiflorum (large flowers) and its variety variegatum has variegated leaves; C. aculeatum.