Centradenia is a genus of trailing shrubs native to the tropics of Central America. Several species are cultivated as ornamental plants and can be obtained through nurseries and trades with other gardeners. These plants have colorful pink flowers with distinctive red-tinged foliage and can be a very showy addition to a tropical garden. In addition to being grown as perennials in the tropics, these plants can also be cultivated like annuals in temperate and cooler regions.
There are fewer than 10 species in this genus, making it relatively small. The individual species have highly variable physical appearances. Most have branching, creeping growth habits and produce leaves in a variety of shapes and sizes. The leaves are overlaid with red and may take on a bronze tinge in the fall months, although Centradenia is an evergreen genus and the plants should not lose their leaves. When the flowers appear, they grow in large clusters of bright pink to mauve blooms with simple petals, and they can look very dramatic against the dark, reddish foliage.
These tropical plants need rich, well-drained soil worked with loam or leaf mold. They prefer to grow in partially shaded areas with ample indirect light. Full sun is usually too intense. Fertilizing regularly will increase growth and promote the development of profuse flowers, and Centradenia species are particularly fond of applications of liquid manure. They can be grown as specimen plantings, massed plantings, groundcovers, and borders.
Propagation of Centradenia species can be accomplished with seeds and cuttings. Seeds are easy to collect as the flowers start to die off and can be stored in a cool dry place for up to one year before they are sprouted. The plants often put out runners that will produce roots and establish themselves, allowing the plants to spread if they are surrounded by good soil, and people can also take cuttings and encourage them to root in mixtures of rich soil. Once a cutting is well established, it can be transplanted.
Centradenia is well suited to container gardening. A cascade of foliage and blooms can look especially striking in a hanging container and may be used to add color under an overhang. In temperate regions, people can experiment with growing the plants in containers outdoors during the warm part of the year and moving them into a greenhouse or conservatory with high humidity, warmth, and lots of indirect light for the winter months.