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Plant care

Free-flowering Streptocarpus (Kranskop Streptocarpus) care

Streptocarpus floribundus

Also called Free-flowering Streptocarpus, Kranskop Streptocarpus.

RHS H1bUSDA 10-12Pet-safeIndoor Leaves 25–50 cm long

Watering rhythm

5-7days

Water when the top 1 cm of compost feels dry; roughly every 5–7 days in summer, less frequently in winter.

Light

Bright indirect light (just back from a sunny window)

Soil

Peat-free, open, moisture-retentive mix with added perlite

Humidity

50–70%

Temp

12–22°C

Pet safety

Pet-safe

Mature size

Leaves 25–50 cm long

Care at a glance

Light

Free-flowering Streptocarpus is what florists mean by "bright spot, no direct sun" — close enough to a south or east window to feel the brightness, with a sheer curtain or a few feet of distance keeping the sun off the leaves. Provide bright but indirect light, such as an east or north-facing windowsill; direct summer sun bleaches and scorches the soft, hairy leaves. Artificial grow-lights work well for winter and low-light settings. A phone lux-meter at the leaf surface should read 1,500-3,000 lux at noon.

Watering

Water free-flowering streptocarpus water when the top 1 cm of compost feels dry; roughly every 5–7 days in summer, less frequently in winter.. The actual day count varies with pot size, light, and season — the finger test (or lifting the pot to feel its weight) is more reliable than a fixed calendar. Empty any drainage saucer afterwards so the pot isn't sitting in water. Streptocarpus prefer to be slightly on the dry side; always allow the surface of the compost to dry before watering again and never leave the pot sitting in a saucer of water. Bottom-watering for 20–30 minutes helps avoid wetting the leaves and crown.

Soil and pot

Free-flowering Streptocarpus grows best in peat-free, open, moisture-retentive mix with added perlite. A 50:50 blend of peat-free multi-purpose compost and perlite drains freely while holding just enough moisture; avoid dense, heavy composts that stay wet around the crown and cause rot. A pot with a working drainage hole is non-negotiable for this species — even free-draining mix will turn soggy in a closed planter. If you love the look of a decorative pot without a hole, use it as a cachepot around an inner nursery pot you can lift out to water.

Humidity and temperature

Free-flowering Streptocarpus sits happiest at around 50–70% humidity and 12–22°C (54–72°F). Appreciates moderate to high humidity reflecting its cool, shaded cliff-face habitat; avoid misting the leaves (encourages fungal spots) and instead use a pebble tray with water or a nearby humidifier. If you keep the room above 12–22°C year-round and avoid placing the plant near a cold draught, a hot radiator, or an air-conditioning vent, you have already handled the two biggest indoor stressors.

Fertilising

Feed free-flowering streptocarpus sparingly. Feed with a high-potash liquid fertiliser (tomato feed type) at quarter-strength every two weeks during the flowering season; reduce to monthly at quarter-strength in winter. Skip fertiliser entirely on a stressed, recently-repotted, or actively wilting plant — fertiliser salts make damage worse, not better. Wait for a round of healthy new growth before resuming a feeding rhythm.

Common problems

Below are the issues we see most often on free-flowering streptocarpus in the Growli community. Each is annotated with the most common cause so you know where to start.

  • Crown and root rotThe most frequent killer; caused by wet, compacted compost or water sitting in the crown. Repot into fresh open mix, remove all soft or blackened tissue, and dust cut surfaces with cinnamon or powdered sulphur before repotting.
  • Powdery mildewWhite powdery coating on leaf surfaces occurs in stagnant, humid air with low light; improve ventilation, remove affected leaves, and apply a potassium bicarbonate or sulphur-based fungicide.
  • Vine weevil larvaeC-shaped grubs eat roots, causing sudden wilt; unpot to inspect and treat with biological controls (Steinernema kraussei nematodes applied in autumn) or a licensed vine weevil compost drench.

Propagation

Leaf cuttings are the standard method: cut a healthy leaf into 4–5 cm sections and insert upright in a 50:50 perlite-and-compost mix; plantlets emerge from the cut veins within 6–8 weeks at 20°C. Can also be grown from very fine seed sown on the surface of damp compost without covering. Propagation is the cheapest, most satisfying way to expand a collection — and it doubles as insurance against losing a mature plant to an accident. Take a backup cutting once the parent is established and healthy.

Toxicity to pets

Free-flowering Streptocarpus is pet-safe. The ASPCA lists Cape Primrose (Streptocarpus spp.) as non-toxic to cats, dogs, and horses. No toxic principles have been identified in the genus. As with any plant material, large quantities may cause mild, transient digestive upset. If you keep cats, dogs, or curious children in the house, weigh placement carefully — a high shelf or a hanging planter is enough for casual safety. For severe ingestion incidents, call your local vet and the ASPCA Animal Poison Control Center (in the US, 888-426-4435).

Pet-safety status is sourced from the ASPCA Toxic and Non-Toxic Plant List, which catalogues the most-asked-about plants for cats, dogs, and horses.

Free-flowering Streptocarpus care — frequently asked questions

What is the common name for Streptocarpus floribundus?

Streptocarpus floribundus is most commonly called Free-flowering Streptocarpus, but it is also known as Free-flowering Streptocarpus, Kranskop Streptocarpus. The names refer to the same species, so care instructions for Free-flowering Streptocarpus apply identically to anything sold as Kranskop Streptocarpus.

How much light does free-flowering streptocarpus need?

Free-flowering Streptocarpus grows best in bright indirect light (just back from a sunny window). Provide bright but indirect light, such as an east or north-facing windowsill; direct summer sun bleaches and scorches the soft, hairy leaves. Artificial grow-lights work well for winter and low-light settings.

How often should I water free-flowering streptocarpus?

Water free-flowering streptocarpus water when the top 1 cm of compost feels dry; roughly every 5–7 days in summer, less frequently in winter.. Streptocarpus prefer to be slightly on the dry side; always allow the surface of the compost to dry before watering again and never leave the pot sitting in a saucer of water. Bottom-watering for 20–30 minutes helps avoid wetting the leaves and crown. The finger-test (or lifting the pot to feel its weight) beats a fixed weekly calendar because pot size, light, and season all change how fast the soil dries.

Is free-flowering streptocarpus toxic to cats and dogs?

Free-flowering Streptocarpus is pet-safe. The ASPCA lists Cape Primrose (Streptocarpus spp.) as non-toxic to cats, dogs, and horses. No toxic principles have been identified in the genus. As with any plant material, large quantities may cause mild, transient digestive upset.

What USDA hardiness zone does free-flowering streptocarpus grow in?

Free-flowering Streptocarpus is rated for USDA zone 10-12 (indoor in most climates) and RHS hardiness H1b. Outside that range, grow it as a container plant that overwinters indoors before the first hard frost.

Free-flowering Streptocarpus deep-dive guides

Every aspect of free-flowering streptocarpus care, each with its own calibrated guide:

Featured in these plant shortlists

Free-flowering Streptocarpus qualifies for 6 curated Growli shortlists — each one filtered objectively from our structured plant-care library, so the selection is consistent and checkable:

Related guides

Free-flowering Streptocarpus is also commonly called Free-flowering Streptocarpus or Kranskop Streptocarpus.