The Browallia speciosa is a small perennial shrub, native to South America; it has a roundish habit, very ramified and reaches 30-40 cm in height. The stems are thin, light brown or green; the leaves are oval, bright green, pointed, furrowed by deep veins. In late spring and winter this plant, commonly called Sapphire flower, produces numerous star-shaped flowers, blue-purple in color, with a white or yellow central eye; there is also a cultivar with white flowers.
Much cultivated as apartment plants, they can also be utilized as annual for the borders in the garden. Sometimes the flowers of Browallia speciosa are utilized for bouquets.
For a better development of the sapphire flower, keep in a luminous place, but preferably not too much exposed to the direct rays of the sun, especially if they are specimens cultivated in pot; the browallias in full earth bloom also in the gardens in half shade, where they can be cultivated as annual.
They fear the cold and therefore from October should be stored indoors or in places with temperatures above 10 ° C.
The ideal temperature is around 18 °C, but they can also withstand higher temperatures if the plants of Browallia speciosa are not exposed directly to sunlight in the hottest hours, while the cold can quickly compromise the specimens of sapphire flower.
As far as the water supply is concerned, in the warmest period water regularly, letting the soil dry slightly between one watering and the other; the plants of Browallia speciosa do not tolerate prolonged periods of drought but do not even like the soaked soil, so check that the substratum allows good drainage. Provide fertiliser for flowering plants every 15-20 days.
The specimens of this type prefer soft and rich of organic matter soils, very well drained; it is possible to utilize some universal balanced soil, mixed with little sand and with coarse-grained pumice stone, for improving the drainage.
For a correct development of the plant it is best to remember to repot it every 2-3 years.
The multiplication of these plants takes place by seed, at the end of the winter; in autumn, it is possible to make cuttings, which are to be rooted in a mixture of sand and peat in equal parts, to be kept humid and in a sheltered place until the new plants are completely rooted.
The most widely used technique is still the one by seed.
Sapphire flower – Browallia speciosa: Parasites and diseases
Be careful of mites and aphids, which often attack the plant massively.
It is essential to take prompt action to prevent parasites from causing even serious damage to the affected specimens. It is possible to use specific pesticide products, or it is possible to use natural products, such as a product based on water and Marseille soap to be vaporized on the plant or water in which garlic has been boiled, always to be used for vaporization on the plants affected by the parasites. A nettle-based macerate can also be a very effective remedy.