Torenia is a genus of flowering annual plants native to the southeast regions of Asia. A number of species are cultivated in captivity as ornamental plants, including a range of cultivars developed specially for gardening. Nurseries sometimes carry Torenia seedlings or seeds, under common names like wishbone flower, bluewings, and clown flower. Gardeners can also collect seeds from mature plants and use them to propagate their own in the following year.
Members of this genus grow in compact mounds and are ideally suited to use as bedding plants. They are in the snapdragon family, and produce small tubular flowers with showy petals. In nature, Torenia usually appears in colors like blue, purple, and lavender, while plants in captivity may be yellow or bred to display other colors. Some are variegated, like blue flowers with yellow throats. The foliage is usually simple and bright green.
These plants require rich soil, preferably worked with lots of compost. The soil also needs to be well drained and to have a neutral pH balance. The plants are native to warm regions and are highly frost tender, growing best in United States Department of Agriculture (USDA) zones six through nine. Full sun to partial shade is recommended for best results, although in a very hot, bright climate, the plants may do better in deeper shade.
In cool climates, Torenia seeds should be started indoors to get seedlings developing before the last chance of frost has passed. Once the weather is warmed up, the seedlings can be planted out. They can be grown in containers and are excellent in borders and edging in addition to massed plantings. Gardeners working with multicolored cultivars can arrange them in a variety of patterns to showcase the bright colors and the array of varieties. Evergreen shrubs and groundcovers make good companion plants for Torenia, as they will offset the colorful flowers.
If a nursery does not stock seedlings, seeds can be ordered through a catalog. Torenia plants that start wilting or browning may be too hot, not receiving enough water, or receiving insufficient nutrients from the soil. If the plants are in a cool area with shade and ample water, the opposite problem may be occurring, and the issue may be resolved by moving the plants to a brighter, sunnier spot and tapering off on their water. Plants growing in poor soil tend to struggle and it is advisable to fertilize at planting and again on a weekly basis to keep plants healthy and strong.