this genus includes about forty species of annual and perennial herbaceous plants originating in Asia and Africa; Torenia fournieri, the most cultivated, is an annual species. It has fleshy, prostrate, very branched stems, covered by small oval leaves, of a bright green color, with a serrated edge; in spring and summer, up to the first autumn colds, it produces many trumpet-shaped flowers of white, purple, pink, yellow or purple depending on the species, usually with a yellow, white or brown throat, however in a contrasting color; There are many cultivars, so we can find bicolor torenie or particular shades of yellow, pink or blue. It is the ideal plant for hanging vases or containers, since the stems tend to fall back, constituting a veritable cascade of flowers; it can also be used in the garden for very decorative flowerbeds, as a ground cover; we remember that the small roundish bushes tend to widen a lot during the vegetative season, it is therefore good to place them well spaced.
As far as the best exposure is concerned, it is good to know that the plants of Torenia fournieri need very bright positions, in full sun or in partial shade; in the hottest periods of the summer it is good to shade it, and the flowering is continuous also for the specimens that do not receive much direct sun. It is good to think of a position that, on hot summer days, allows the plant to be sheltered from the hottest direct sunlight.
Fears the cold, in fact it is cultivated as an annual species since it is not resistant to cold winter temperatures and small plants born at the beginning of spring must be protected until the arrival of hot days.
For the correct development and the best flowering of the Torenia fournieri it is advisable to water regularly, letting the soil dry slightly between one watering and another and checking that the formation of dangerous stagnation of water does not occur. From the beginning of flowering, provide fertilizer for flowering plants dissolved in the water of the watering every 7-10 days.
Torenia fournieri prefers loose, well-drained soils, rich in organic matter; for the best substrate, use balanced soil mixed with sand and manure, or add slow-release fertilizer. Before planting them in the garden, work the soil well, so that the roots of the specimens can sink into a soft sub-layer.
The soil must allow proper drainage, in order to avoid the formation of unhealthy water stagnations for this kind of specimens.
The multiplication of Torenia fournieri occurs by seed. The small seeds must be sown in seedbeds in March, and kept in a bright and warm place; it is advisable to water the seedlings by immersion, to avoid that the seeds, of very small dimensions, are dispersed by the water. Planting when the outside temperatures are milder and there is no longer the possibility of abrupt drops in temperature, a factor that would irreparably compromise these plants.
Torenia fournieri: Pests and diseases
pay attention to aphids, which ruin young shoots and buds; sometimes it can be affected by powdery mildew or gray mold. It is good to provide broad-spectrum treatments that provide adequate protection to prevent parasites from ruining the specimens. As for the gray mold, check that the soil is sufficiently drained and does not retain too much moisture, a factor that can easily cause the onset of this disease.