Torenia is a pretty annual that hails from tropical African and Asian woodlands. This branching annual is not frost hardy but grows rapidly to a height of about 12 inches with a spread of 8 inches. It flowers in summer and fall, producing racemes of trumpet-shaped, two-lipped flowers that look a bit like snapdragon blooms. There are two lobes on the upper lips and three lobes on the lower lips.
Torenias make attractive plants for containers in sheltered positions. Pinch out the growing shoots of young plants to encourage them to get bushy.
Now that we have had our first frosts in the Midwest, I am thinking about what to plant next year.
‘Summer Wave’ is a trailing, long-flowering strain of torenia that has large blue flowers, but purplish-blue, red, pink and white varieties are also available. The leaves of these plants are light to dark green and ovate to elliptical in shape, and they have toothed edges. Grow them in fertile, well-drained soil in part shade.
Another pretty blue annual to consider next spring is Scaevola, or fan-flower as it is also called. I am partial to it as, like me, it hails from Australia. It has profuse blue, mauve, purple, or white flowers in sun or part shade, and it drapes well over the sides of pots. ‘Blue Wonder’ is very pretty as well as being drought tolerant.