Geranium sanguineum (Bloody cranesbill) care

Light

Most houseplants will scorch where geranium sanguineum thrives. Give it the windowsill you'd otherwise leave empty because everything else burned there. Best in full sun for dense growth and maximum flowering, though it tolerates light partial shade. In deeper shade it grows looser and flowers less; an open sunny site also gives the best autumn leaf colour. A plant moved abruptly from low light to direct sun bleaches in 48 hours — always acclimatise over a week.

Watering

Aim for when the top 4-5 cm of soil is dry; weekly while establishing, infrequently once mature for geranium sanguineum, but treat that as a starting point rather than a rule. A south-facing summer windowsill will dry the pot twice as fast as a north-facing winter room. Lift the pot; if it feels noticeably lighter than it did wet, water it. Notably drought-tolerant after the first season thanks to a stout rootstock. Water to establish, then only in extended dry spells. It strongly dislikes soggy soil, which causes crown rot.

Soil and pot

Geranium sanguineum grows best in well-drained, low-to-average fertility loam, sand or chalk. Thrives in light, free-draining soils and tolerates poor, stony and chalky ground at neutral to alkaline pH. Avoid heavy, wet clay; if needed, add grit to improve drainage. Lean soil keeps the mound tight and floriferous. 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

Geranium sanguineum sits happiest at around Low to moderate, ambient outdoor humidity and -34 to 30°C (-29 to 86°F). An undemanding outdoor perennial with no humidity requirements. It tolerates exposed, dry sites well; good airflow keeps the dense mound healthy. 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 geranium sanguineum sparingly. Very low feed needs and best kept lean. A thin spring mulch of compost is ample; rich feeding produces loose, floppy growth and fewer flowers. Skip high-nitrogen fertilisers entirely. 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 geranium sanguineum in the Growli community. Each is annotated with the most common cause so you know where to start.

• Loose, floppy growth — Caused by shade or over-rich soil. Grow in full sun on lean, well-drained ground and avoid feeding to keep the mound dense and self-supporting.
• Crown rot in wet ground — Waterlogged or heavy clay soil rots the rootstock over winter. Improve drainage with grit, plant slightly proud, and never let it sit wet.
• Mid-summer tiredness — Flowering can pause and foliage tire after the main flush. Shear lightly after the first bloom to encourage fresh leaves and a second, lighter flowering.
• Self-seeding — Species plants set seed and can pop up around the garden. Trim spent flowers if you want to limit volunteers, or leave them for relaxed ground cover.

Propagation

Divide established clumps in spring or autumn, replanting vigorous rhizome sections. The species also comes readily from seed sown in autumn or spring, though seedlings vary; named forms are best divided to stay true. 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

Geranium sanguineum is mildly toxic to pets. Geranium sanguineum belongs to the true Geranium genus (cranesbills), which the ASPCA does not individually list as toxic or non-toxic. It is frequently confused with the ASPCA-listed toxic 'geranium', Pelargonium species (toxic principles geraniol and linalool). Without an affirmative ASPCA non-toxic listing, treat with caution and verify with a vet rather than assuming pet-safe. 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.

Geranium sanguineum deep-dive guides

Every aspect of geranium sanguineum care, each with its own calibrated guide:

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

Featured in these plant shortlists

Geranium sanguineum qualifies for 4 curated Growli shortlists — each one filtered objectively from our structured plant-care library, so the selection is consistent and checkable:

• Best drought-tolerant houseplants — Houseplants that prefer to dry out — forgiving of forgotten watering and ideal for travel or busy weeks.
• Best flowering houseplants — Indoor plants grown for their blooms — selected from the flowering species in Growli’s plant-care library.
• 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

Geranium sanguineum is also commonly called Bloody cranesbill.

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• All 2464 plant care guides in the Growli library