Streptocarpus

This group consists of 132 species of annuals and frost-tender perennials, which are close relatives to African Violets (Saintpaulia) and belong to the same family, Gesneriaceae. Cape Primrose, as they are commonly called, are natives of the wooded mountains of South Africa. They make excellent houseplants in cooler regions. These plants have been widely hybridized and there are numerous interesting and attractive varieties available. These plants produce attractive leaves, which may have wavy edges, and bear beautiful, trumpet-shaped flowers intermittently throughout the year. S. caulescens is a pretty species that grows up to 18 inches high. It forms clumps of fleshy, oval, dark green leaves. The small flowers are borne in clusters atop long, thin stalks. They may be white or violet with violet stripes. S. saxorum (False African Violet) forms round clumps of fleshy, fuzzy, oval, dark bluish-green leaves. In late summer, small lilac flowers with white throats are produced. S. 'Constant Nymph' is an evergreen variety that forms rosettes of strap-shaped, fleshy and wrinkled, dark green leaves. Clusters of small, funnel-shaped flowers are borne intermittently throughout the year. They are purplish-blue with darker veins and yellowish throats.

Pot Cultivation

Cape Primrose require a minimum temperature of 50° to 60° F. They can be grown as houseplants in cool climates. Don't plant them in too large a container; it is better for the plants to be on the pot-bound side as this will aid in flower production. These plants should be grown in moist, humus-rich soil (such as loam, leaf mold & decayed manure with a bit of sand and bone meal added) in a humid atmosphere. After potting, shade them for a few days, eventually choosing a location in bright, but indirect light, as too much sun will scorch the leaves. Allow the soil to become dry to the touch in between waterings. Water from the bottom to prevent the leaves from getting wet and rotting at the base. If this happens, remove the damaged leaf and make sure you aren't overwatering. Once the flowers begin to grow, feed every few weeks with a high potash fertilizer. Pick off any dead flowers. In the winter, water less often and do not fertilize again until spring. The plants should also be repotted into slightly larger containers in the spring. Cape Primrose may be subject to attack by greenflies, which can easily be destroyed (Look up Greenflies in our Pest & Diseases section.).

Propagation

These plants may be increased by division after flowering, sowing seeds in the spring, and be leaf cuttings in the spring or early summer. Seeds may be sown in pots of finely sifted loam, leaf mold and sand. Set the containers in a glass-covered case in a warm room. The compost must remain moist, but not waterlogged. Once the seedlings sprout, remove from the case. They should be potted separately in 21/2-inch pots before they become too crowded. When they are well-rooted in the small pots, they can be transferred to larger containers (5- or 6-inch pots) in which they will bloom. Leaf cuttings may be taken in the spring or early summer. Take a young leaf from the center of the plant and place the cut end in a mixture of half compost and half vermiculite or perlite. Set in a bright location out of the sun. The leaf should be rooted after about a month and soon after a new plant will grow from the base of the leaf.