Fertilising guide
How to fertilise Geranium sanguineum (Geranium sanguineum)— schedule & NPK
Also called Bloody cranesbill.
More about geranium sanguineum
About Geranium sanguineum
Geranium sanguineum · also called Bloody cranesbill · flowering
Geranium sanguineum, bloody cranesbill, is a tough, compact hardy geranium forming a dense mound of deeply cut dark-green leaves studded with magenta-pink, saucer-shaped flowers through summer. Its foliage often reddens in autumn. Drought-tolerant once established and happy in poor, well-drained soil, it makes excellent low ground cover for sunny banks and edges.
Growth habit: Compact, mound- to mat-forming herbaceous perennial spreading slowly by rhizomes to make weed-suppressing ground cover, with wiry stems and finely dissected foliage that colours red in autumn.
Watch for — 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.
What fertiliser geranium sanguineum actually wants — and why
Geranium sanguineum is a heavy-blooming flower with a big appetite — a regular high-potash feed through the season is what drives a long, dense display.
A high-potassium ("high-potash") flowering feed — tomato-style or a dedicated bloom/rose feed. Potassium powers flowering; a high-nitrogen feed gives you a leafy plant with disappointing bloom.
For the language behind the three numbers on the bottle — what nitrogen, phosphorus and potassium each do — see the NPK ratio explained entry. The short version for geranium sanguineum: match the feed to the job the plant is doing right now, not to a generic “plant food” on the shelf.
How often to feed geranium sanguineum, and which months
Feeding only earns its keep while the plant is in active growth and can use the nutrients — pour feed into a dormant or low-light plant and it simply builds up as root-burning salt. For geranium sanguineum:
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. For a hungry bloomer that means feeding regularly — sparingly through the growing season — right through flowering across the main season (spring through early autumn), tapering as blooming ends.
The dormant-season rule matters more than the exact interval: skip feeding entirely when geranium sanguineum is resting. For the wider context on indoor feeding rhythms across the seasons, the houseplant fertiliser schedule walks through the year month by month.
What strength to mix for geranium sanguineum
Follow the flowering-feed label rate for geranium sanguineum, or half strength if feeding very frequently. These plants genuinely use the nutrients — under-feeding shows up fast as a thin display.
Feeding always goes onto already-damp soil, never dry roots — water geranium sanguineum first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the geranium sanguineum watering schedule.
Signs you are over-feeding geranium sanguineum
Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for geranium sanguineum:
- Lots of lush leaves but few flowers (too much nitrogen).
- Scorched leaf edges and salt crust from too-strong or too-frequent feeds.
- Soft, sappy growth prone to aphids and mildew.
Signs you are under-feeding geranium sanguineum
- Sparse, small, short-lived flowers and pale foliage.
- A tired plant that stops blooming early in the season.
- Weak growth and poor repeat-flowering after the first flush.
If the symptoms point at watering, light or roots rather than nutrition, the full geranium sanguineum care brief covers soil, humidity and the common problems for this species.
Flushing and leaching the salts
Container-grown geranium sanguineum accumulates feed salts fast with frequent feeding — water until it drains each time and flush pots with plain water every few weeks to prevent scorch.
Organic vs synthetic feeds for geranium sanguineum
Organic options
A liquid comfrey or seaweed feed (naturally potassium-rich) plus compost or well-rotted manure as a mulch. UK: comfrey feed, organic Tomorite, or rose feed; US: Espoma Rose-tone or Neptune's Harvest. Feeds and improves soil.
Synthetic / liquid feeds
A high-potash flowering feed on a regular cadence — UK: Tomorite (Levington), Phostrogen or a specialist rose feed; US: Miracle-Gro Bloom Booster or a rose food. Fast, reliable bloom response.
Brand names are examples, not endorsements, and UK and US ranges differ — check the label’s own NPK and dilution rate, since formulations change.
Fertilising geranium sanguineum — frequently asked questions
What fertiliser does geranium sanguineum need?
A high-potassium ("high-potash") flowering feed — tomato-style or a dedicated bloom/rose feed. Potassium powers flowering; a high-nitrogen feed gives you a leafy plant with disappointing bloom. Geranium sanguineum is a heavy-blooming flower with a big appetite — a regular high-potash feed through the season is what drives a long, dense display.
How often should I feed geranium sanguineum?
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. 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. For a hungry bloomer that means feeding regularly — sparingly through the growing season — right through flowering across the main season (spring through early autumn), tapering as blooming ends.
What strength of feed for geranium sanguineum?
Follow the flowering-feed label rate for geranium sanguineum, or half strength if feeding very frequently. These plants genuinely use the nutrients — under-feeding shows up fast as a thin display.
What does over-feeding geranium sanguineum look like?
Lots of lush leaves but few flowers (too much nitrogen). Scorched leaf edges and salt crust from too-strong or too-frequent feeds. Soft, sappy growth prone to aphids and mildew. Using a high-nitrogen general feed on geranium sanguineum is the headline mistake — you grow a big leafy plant with few flowers. The second is simply under-feeding a genuinely hungry bloomer and getting a sparse, short display.
Should I flush the soil of geranium sanguineum?
Container-grown geranium sanguineum accumulates feed salts fast with frequent feeding — water until it drains each time and flush pots with plain water every few weeks to prevent scorch.
Keep reading
- Geranium sanguineum care — the full brief (light, soil, humidity, problems, pet safety)
- How often to water geranium sanguineum — the watering schedule
- The houseplant fertiliser schedule — feeding through the year
- NPK ratio explained — what the three numbers on the bottle mean
- How to fertilise peace lily
- How to fertilise bird of paradise
- How to fertilise hoya
- All 2464 fertilising guides in the Growli library