A charming species with delicate flowers and a creeping habit, Streptocarpus kirkii is very different from the large-flowered Cape Primroses commonly grown as houseplants. Native to eastern Africa, it forms low rosettes of softly hairy leaves and produces elegant violet-blue flowers over a long period when grown in the right conditions. It’s an excellent choice for terrariums, vivariums or bright, humid indoor spaces.
Scientific Name
Streptocarpus kirkii
Named in honour of Sir John Kirk, the Scottish physician, explorer and botanist who collected plants throughout East Africa during the 19th century.
Common Name(s)
Cape Primrose, Kirk’s Streptocarpus
Origin
Eastern Africa, including Tanzania and Malawi, where it grows on shaded rocky outcrops and in moist forest habitats.
Light
Prefers bright, indirect light. An east-facing window is ideal, although it also grows well under grow lights. Avoid direct afternoon sun, which can scorch the leaves.
Water
Keep the compost lightly moist, allowing the top 1–2cm to dry slightly between waterings. Water around the base of the plant and avoid wetting the leaves, as they can mark easily. Reduce watering slightly during the cooler months.
Humidity
Enjoys moderate to high humidity (around 50–70%). It appreciates increased humidity but should always have good air circulation to help prevent fungal problems.
Temperature
Thrives between 16–24°C. Avoid temperatures below 10°C and protect from cold draughts.
Soil
Use a light, free-draining mix. A blend of peat-free houseplant compost with added perlite and fine orchid bark works well, providing both moisture retention and excellent drainage.
Feed
Feed every 2–4 weeks during spring and summer with a balanced liquid houseplant fertiliser at half strength. Reduce feeding during autumn and winter.
Growth
A compact, spreading perennial with softly textured green leaves. It remains relatively small, typically reaching 10–15cm tall while spreading gradually by offsets.
Flowers
Produces delicate, tubular violet to lavender-blue flowers with pale throats, usually from spring through autumn. With good care, flowering can continue for many months.
Toxicity
Generally considered non-toxic to cats and dogs, although it is still best to prevent pets from chewing the foliage.
