Roundleaf Sundew (Common sundew) care

Light

Aim for at least 4-6 hours of direct sun on the leaves. Full sun outdoors or the brightest possible spot; strong light keeps the tentacles red and dewy. Shade produces weak, green, non-trapping leaves. If your only bright window faces south, that's perfect for roundleaf sundew — same window any aroid would fry on.

Watering

Watering roundleaf sundew: keep saturated; stand in 1-3 cm of pure water through the growing season. The number that matters isn't the day of the week — it's how dry the top 2-3 cm of the pot feels. A finger in the soil tells you more than a watering app. After every watering, tip the saucer. Rainwater, distilled, or RO only. In winter dormancy keep the peat damp but reduce standing water to avoid rotting the hibernaculum.

Soil and pot

Roundleaf Sundew grows best in acidic mineral-free bog mix. Pure sphagnum peat or 1:1 peat and sand; live sphagnum is ideal. No lime, compost, or fertiliser. 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

Roundleaf Sundew sits happiest at around 50-80% humidity and -15-28°C (5-82°F). A bog plant that enjoys high humidity but grows fine outdoors in open air. Good ventilation prevents fungal rot, especially as it enters dormancy. If you keep the room above 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 roundleaf sundew sparingly. Never fertilise the roots. It obtains nutrients from trapped midges and gnats; outdoors it feeds itself. Mineral feed will kill it. 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 roundleaf sundew in the Growli community. Each is annotated with the most common cause so you know where to start.

• Rot during winter — Standing water on the dormant hibernaculum causes rot. Keep merely damp, not flooded, and ensure airflow over winter.
• Plant declines after a year indoors — It needs a real cold dormancy (around 0-10°C for 3-4 months). Without winter chill it weakens and dies; grow it outdoors or in an unheated space.
• Green, dewless leaves — Too little light or mineral-laden water. Give full sun and use only rainwater or RO.
• Leaves blacken in autumn — Normal dormancy onset, not disease — the rosette is retreating to its hibernaculum. Reduce water and leave it cold.

Propagation

From seed, which requires cold-moist stratification (several weeks chilled and damp) before surface-sowing. Also propagates from leaf cuttings on wet sphagnum and from gemmae/division of established rosettes. 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

Roundleaf Sundew is mildly toxic to pets. Drosera is not individually listed by the ASPCA, so pet-safe status cannot be confirmed; treat with caution and verify with a vet. The plant has a long folk-medicine history and no serious toxic principle is documented, so ingestion likely causes at most mild gastrointestinal upset, but it is best kept away from pets that might chew it. 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.

Roundleaf Sundew deep-dive guides

Every aspect of roundleaf sundew care, each with its own calibrated guide:

• Roundleaf Sundew watering schedule
• Roundleaf Sundew light requirements
• Best soil mix for roundleaf sundew
• Roundleaf Sundew fertilizing guide
• When to repot roundleaf sundew
• How to propagate roundleaf sundew
• Roundleaf Sundew growth rate & size
• Roundleaf Sundew cold hardiness
• Roundleaf Sundew temperature & humidity
• Is roundleaf sundew toxic to cats & dogs?
• Is roundleaf sundew toxic to cats?
• Is roundleaf sundew toxic to dogs?
• Getting roundleaf sundew to bloom

Featured in these plant shortlists

Roundleaf Sundew qualifies for 5 curated Growli shortlists — each one filtered objectively from our structured plant-care library, so the selection is consistent and checkable:

• Best humidity-loving houseplants — Houseplants that thrive in a bathroom, kitchen, or by a humidifier — selected by documented humidity preference.
• Best flowering houseplants — Indoor plants grown for their blooms — selected from the flowering species in Growli’s plant-care library.
• Best small & tabletop houseplants — Compact houseplants that stay under about 40 cm — desk, shelf and windowsill plants that never outgrow a small space.
• Best houseplants for full sun — Houseplants that want direct sun — the species for a hot south or west-facing windowsill where shade-lovers scorch.
• Best houseplants for a cool room — Houseplants that tolerate cool conditions down to about 10°C — for an unheated spare room, hallway, porch or a home kept cool.
• Browse all 29 plant shortlists — pet-safe, low-light, drought-tolerant and more

Related guides

Roundleaf Sundew is also commonly called Common sundew.

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