Streptocarpus (Cape Primrose): Care, Blooms and Propagation

Streptocarpus, or Cape primrose, is a relative of the African violet and gloxinia that can flower almost non-stop from spring to autumn. Dozens of bells — white, pink, blue, purple, veined, edged or double — rise above a rosette of long crinkled leaves. Collectors love it for the endless varieties and easy propagation. Here is how to care for streptocarpus so it blooms long and generously.

What is streptocarpus

Streptocarpus is a genus of the gesneriad family from southern Africa and Madagascar. The name means “twisted fruit”: after flowering it forms narrow, spirally twisted seed pods. Indoor varieties are hybrids with a rosette of long leaves and flower stems carrying 2–10 blooms each. There are unusual species too, such as S. saxorum, with small fuzzy leaves on branching stems, grown as a trailer.

Its care is similar to that of African violets — see types of African violets.

Light and temperature

For abundant flowers streptocarpus needs 12–14 hours of bright indirect light daily: an east or west window, plus a grow light in winter. Direct sun scorches the leaves, while in shade it grows leaves but no flowers. Keep it at 18–25 °C; above 28 °C flowers shrink and fade quickly. In winter it can rest at a cooler 15–18 °C.

View full-size photoStreptocarpus blooms from spring to autumn, forming a rosette of long leaves and many flower stems.

Watering, soil and pots

Streptocarpus tolerates slight underwatering better than overwatering. Water when the top layer is dry, around the pot edge or into the saucer, and tip out the excess after 15–20 minutes. Its roots are fine and shallow, so use a wide, shallow pot and a light mix: African violet compost with perlite and vermiculite. Feed every 2 weeks while flowering.

Leaf propagation: “toasters” and cross-sections

• Lengthwise sections (“toasters”) — cut a healthy leaf lengthwise, removing the midrib. Insert both halves cut edge down 0.5–1 cm into moist mix, like bread in a toaster. Plantlets appear from the side veins in 1–2 months.
• Cross-sections — cut the leaf across into 4–5 cm strips and plant them base down.
• Division — split a mature plant with several crowns when repotting.

Keep cuttings in a propagator at 22–25 °C in bright indirect light; pot up plantlets at 2–3 cm.

View full-size photoLengthwise leaf sections of streptocarpus for propagation ('toasters') in moist substrate.

Why leaves dry and flowers fail

• Drying leaf tips — partly natural, as old leaves die back from the tip; dry air and heat make it worse. Trim the dry part.
• No flowers — too little light, too big a pot or too much nitrogen.
• Wilting in moist soil — overwatering and root rot.
• Small, short-lived flowers — heat above 28 °C.
• Thrips — pollen scattered on petals, silvery patches on leaves.

Rejuvenating and repotting

Every 1–2 years refresh streptocarpus: repot in fresh mix, remove old leaves and divide overgrown clumps. Older plants flower less, so collectors restart favourite varieties from leaf cuttings. See how to repot houseplants.

Is streptocarpus safe

Streptocarpus is considered non-toxic to people, cats and dogs, so it suits any room, including children’s rooms. It shares a windowsill happily with African violets and gloxinia, which need similar conditions. More flowering plants: houseplant names and care; browse potted plants.

FAQ

How often does streptocarpus flower?

With enough light, almost continuously from spring to autumn, and in winter under a grow light.

View full-size photoA mature streptocarpus is divided during repotting to rejuvenate the plant.

Why is my streptocarpus not flowering?

Usually too little light, too large a pot or too much nitrogen.

Should I mist streptocarpus?

Better not: water on leaves and flowers can cause spots. Raise humidity with a pebble tray.

Author: Maria Svitlovir

Graduated from Taras Shevchenko National University of Kyiv, Institute of Biology and Medicine (2001). BSc in Biology, MSc in Horticulture. Writes about plants, works at a garden centre selecting and repotting plants, and contributes to plant reference guides.

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