It is a small evergreen plant native to southern Africa. It consists of a dense rosette of large green, round, thin and wrinkled leaves; in spring and summer from the rosette of leaves rises a stem that carries some flowers, generally blue or white, but there are numerous hybrids of different colors; there is also a species consisting of a single large leaf, with stems of blue flowers, when the plant has produced the seeds the only leaf dies, but often it takes years before it flowers. The Streptocarpus they are widely used as houseplants as they are easy to grow and have a long flowering period. Flower stems can also be used in bouquets. This plant is also known as the Cape primula.
For a better development of the primula of the head, place the plant in a luminous place, but not directly exposed to sunlight, which causes serious burns of the leaves; they fear the cold, so in winter they should be kept indoors. Generally the Streptocarpus they grow better in places with cool climate, they fear the great heat of the summer months, in July and August it is therefore good to keep them away from the sun in a very ventilated place.
The ideal temperature for the cultivation of these plants is around 22 ° C and, in winter, it is good to place it in a place where it does not fall below 16 ° C.
These small plants need regular watering, but not too abundant: it is good to water them at least once or twice a week, waiting for the soil to dry a little between one watering and another since the primula of the head can present serious problems. in the presence of water stagnation. In winter the watering decreases, remembering however to moisten the soil quite often.
It is interesting to know that the leaves should not be wet because they risk getting stained easily and could present the presence of mold.
From March to October, provide fertilizer for flowering plants every 10-15 days, mixed with the water used for watering.
To plant these plants, use a universal soil, lightened with expanded clay or pumice stone to increase drainage, in fact streptocarpus do not like soils that are too heavy and poorly draining, a factor that can cause the onset of dangerous root rot.
It is good to proceed with an annual repotting in the spring period, using a vase a little larger than the previous one.
The multiplication to obtain new specimens takes place by seed in spring; in late spring it is also possible to practice leaf cuttings, which are taken near the ground level, the petiole is immediately inserted into a mixture of peat and sand in equal parts; it is advisable to choose new and healthy leaves.
Cape Primula - Streptocarpus: Pests and diseases
Pay attention to aphids and cochineal; excess water can cause root rot. Aphids, or lice, can be eliminated with one of the many insecticidal products available on the market, or with the use of natural products, based on nettle or garlic. Macerates are prepared and then sprayed on the affected leaves. For the cochineal, in addition to the usual specific products, if their presence is limited, it is possible to intervene with the help of a cloth with alcohol to eliminate them manually.