Geranium sanguineum

Plant Profile & Key Characteristics

Overview: Bloody cranesbill (Geranium sanguineum) is a low, mounding hardy perennial 20-40 cm grown as an ornamental and groundcover for its magenta-pink flowers and deeply cut foliage.

Quick Specifications

Specification	Attribute
Plant Type / Life Cycle	Perennial
Foliage Type	Semi-evergreen
Mature Size	20-40 cm (8-16 in)
Growth Rate	Fast to moderate
Root System	Rhizomatous
Toxicity	Non-toxic
Hardiness	USDA zones 3-8

Growth Form & Structure

• Height & Spread: 20-40 cm, forming a spreading mound; also grown in containers.
• Growth Habit & Form: Clumping to spreading rhizomatous groundcover.
• Lifespan & Maturity: Long-lived hardy perennial.

Anatomy & Physical Features

• Leaves & Foliage: Green, deeply palmate leaves that often colour in autumn.
• Flower Characteristics: Flat, five-petalled flowers in pink, purple or white.

Primary Uses & Landscape Value

• Functional & Ornamental Roles: Groundcover, edging and border plant; pollinator plant; suited to containers.

Care Guide: Planting, Soil & Watering

Overview: Bloody cranesbill is a hardy perennial geranium for cool-temperate gardens (zones 3-8) that flowers in full sun to half shade. It likes cool winters and moist but well-drained soil, and is easy and long-lived.

Quick Care Requirements

Requirement	Ideal Condition
Planting Season	Spring, summer or autumn
Growth Rate	Moderate to fast
Soil Type	Moist but well-draining
Water Need	Moderate to high; keep the soil evenly moist

Planting & Establishment

• Best Planting Season: Plant in spring, summer or autumn; it is fully hardy and benefits from a cold winter rest.
• How to Plant:
  • Hole Preparation: Dig a hole slightly wider than the root ball in well-worked, free-draining soil.
  • Soil Amendments: Mix in compost to hold moisture while keeping the soil open and well-drained.
  • Planting Depth: Set the crown at soil level and firm gently.
• Growth Speed & Expectations: A quick, spreading grower forming a mound about 20-40 cm high that knits into weed-suppressing ground cover.

Soil, Watering & Drainage Care

• Soil Mix & Drainage Needs: Wants moisture-retentive yet well-drained soil; adaptable and easy in the ground or a container.
• Watering Schedule & Technique:
  • Young / Newly Planted: Keep newly planted clumps evenly moist while they establish.
  • Established: Water regularly to keep the soil moist, though established clumps tolerate short dry spells.
  • Seasonal Adjustments: More water in summer heat; little needed over winter dormancy.

Climate, Light & Hardiness

Geranium sanguineum, the bloody cranesbill, is a tough, very cold-hardy perennial for temperate and mild-subtropical gardens, thriving in full sun to half shade on well-drained soil. Site data rates it in zones 3–8; it takes hard winters in stride and is more sun- and heat-tolerant than many cranesbills.

Quick Climate Specifications

Climate Zones	Temperate to mild subtropical
USDA Hardiness Zones	3–8 (site data)
Approx. Survival Minimum	Established plants survive zone 3 winters (roughly −40 °C / −40 °F)
Frost Tolerance	High
Light Conditions	Full sun to half shade
Wind Tolerance	High (low, mounding habit)

Sunlight & Light Exposure

Optimal Light Setup

Full sun gives the densest mound and best flowering; half shade is tolerated and helps in hotter regions.

Direct Sun Requirement

It flowers best in full sun and, unlike the woodland cranesbills, positively enjoys open, sunny positions.

Best Exposure / Orientation

An open, sunny, well-drained site suits it; light afternoon shade eases the warm end of its range.

Temperature Extremes & Hardiness

USDA Hardiness & Regional Limits

Site data gives zones 3–8. The low end reflects excellent winter-cold survival; toward zone 8 summer heat becomes the limiting factor.

Cold Damage & Winter Protection

Extremely winter-hardy; it dies back and reshoots reliably and needs no protection.

Frost Sensitivity

Very low - a cold-loving perennial that requires a cold winter to perform well.

Extreme Heat Tolerance

Moderate; it copes with more heat and sun than most cranesbills but still prefers not to bake, so some afternoon shade helps in hot-summer climates.

Wind, Humidity & Microclimate

Wind Tolerance

High - the low, spreading mound is very wind-resistant.

Rainfall & Seasonal Moisture

Adaptable, tolerating both drier and moister conditions on well-drained ground; it dislikes waterlogging.

Microclimate Recommendations

Easy and unfussy; in hot regions a slightly cooler, part-shaded aspect keeps it in good condition through summer.

Growing in Pots, Balconies & Indoors

Geranium sanguineum (bloody cranesbill) is a hardy, sun-loving perennial, and the grower does not list it as a houseplant – it wants full sun and a winter chill. It is, however, a superb container plant for a sunny patio or balcony, forming a neat mound of finely cut leaves and bright flowers.

Quick Details

• Container Size: A medium pot (about 5-12 L / 1.3-3 gal) for a clump
• Indoor Suitability: Not a houseplant – it needs full sun and a cold winter rest; only the sunniest cool sill could hold it
• Best Spot: Full sun to half shade
• Soil & Drainage: Ordinary, free-draining potting mix; it resents soggy soil
• Watering in Pots: Average to generous – water when the top dries; it tolerates some drought but not waterlogging

Indoors & On the Windowsill

• Not a houseplant: The grower marks it unsuitable indoors. It needs full sun and a cold winter rest, which a room cannot provide.
• Sunny sill at most: Only the brightest, sunniest windowsill in a cool room could hold it, and it is far happier outside.
• Overwinter outdoors: Leave the pot outside; it is fully hardy and the winter cold does it good.

On a Balcony or Patio

• A sunny mound: Give it the sunniest spot; it forms a tidy, free-flowering clump ideal for pots and troughs.
• Even moisture, good drainage: Water when the top dries; it tolerates some drought but resents soggy soil.

Choosing the Pot, Soil & Long-Term Care

• Pot & drainage: Good drainage holes and no standing saucer; terracotta breathes, plastic holds moisture.
• Potting mix: Ordinary free-draining potting mix enriched with organic matter.
• Feeding: A light feed through the growing season is enough – too rich and it flops.
• Repotting & dividing: Every couple of years refresh the mix and divide congested clumps to keep them vigorous.

Fertilizing & Feeding

A light feeder: balanced feeding through the growing season is plenty, and these tough perennials flop and lose bloom if overfed; feeding eases off while they are dormant.

Quick Fertilizing Specs

Feeding Level	Light feeder
Main Nutrient Priority	Balanced feeding with adequate nitrogen; balanced feeding drives bloom, not high phosphorus
Best Feeding Period	Spring through the flowering season
Organic Options	Compost and other organic matter
Reduce/Stop Feeding	Ease off as bloom finishes and the plant rests
Micronutrients	Usually supplied by a complete fertilizer; correct only diagnosed problems
Soil pH	Slightly acidic to near neutral

Feeding by Growth Stage

Spring growth before bloom

Build healthy leaves and stems to support the coming bloom.

Nutrient direction	A balanced complete fertilizer with adequate nitrogen; balanced feeding, not a high-phosphorus bloom product, drives flowering.
Timing	As growth resumes in spring.
Frequency	A light feeding as active growth begins.
Fertilizer types	A balanced complete fertilizer, Compost or other organic matter
Precautions	Adequate nitrogen and balanced feeding support bloom; excess nitrogen pushes leaves at the expense of flowers.

Flowering season

Sustain steady flowering through the bloom season.

Nutrient direction	Continue balanced feeding to keep plants vigorous and blooming.
Timing	Through the flowering season.
Frequency	Light, steady feeding across the bloom period.
Fertilizer types	A balanced complete fertilizer
Precautions	Balanced, moderate feeding is best; excess fertilizer wastes nutrients rather than boosting bloom.

Dormancy or cool-season rest

Let the plant rest as growth and bloom slow for the season.

Nutrient direction	None – withhold fertilizer while the plant rests.
Timing	After the plant dies back in autumn and through winter dormancy.
Frequency	No feeding during this rest; resume only when active growth returns.
Fertilizer types	No feeding at this stage; hold off fertilizing until active growth resumes.
Precautions	Do not fertilize a resting plant; wait for new spring growth.

Nutrient Deficiency Signs & Corrections

Older, lower leaves fade to pale green or uniform yellow and overall growth slows.

Possible causes	low available soil nitrogen, nitrogen leaching from heavy watering or rain, thin soil low in organic matter
Appears first on	older, lower leaves
What to check	recent feeding history, soil organic matter, watering and drainage
Possible correction	Apply a nitrogen-containing complete fertilizer and build soil organic matter, then water evenly.

Youngest leaves yellow between the veins while the veins themselves stay green.

Possible causes	high soil pH reducing iron and manganese availability, waterlogged or poorly drained roots, genuinely low micronutrient supply
Appears first on	new, young leaves
What to check	soil pH and drainage, watering habits, whether symptoms are on the newest growth
Possible correction	Correct soil pH if high, improve drainage, and apply a chelated iron or manganese product per its label.

Plenty of leafy growth but few flowers.

Possible causes	excess nitrogen feeding favoring leaves over flowers, too little light for good bud set, a young or recently divided plant not yet settled
Appears first on	the whole plant, seen as leafy growth with sparse flowers
What to check	how nitrogen-heavy recent feeding has been, light exposure through the day, plant age and establishment
Possible correction	Ease back on nitrogen, shift to balanced feeding, and ensure adequate light; avoid high-phosphorus bloom-booster products.

Pruning, Training & Seasonal Maintenance

Geranium sanguineum (bloody cranesbill) is a clump-forming hardy herbaceous perennial with no woody structure, so pruning is really shearing and tidying: deadhead or shear the whole clump after the main flush to strip spent flowers and tired leaves and to drive a fresh mound of foliage (and often a lighter rebloom). Cut the clump down in late autumn or winter as it dies back. This long-blooming, sun-tolerant species responds especially well to a shear after the first flush, coming back as a fresh, tidy mound with repeat flowers.

Quick Pruning & Maintenance Specs

Pruning Tolerance	High – shear the whole clump; it regrows from the crown
Primary Pruning Window	After the main early-summer flush (shear back)
Secondary Maintenance Window	Autumn/winter cut-down of spent foliage
Typical Frequency	One mid-season shear plus one end-of-season cut-down
Main Objective	Deadhead, refresh foliage, encourage rebloom, tidy the clump
Young Plant Priority	Let the crown establish; remove only damaged leaves
Mature Plant Priority	Shear after the flush; divide every few years to reinvigorate
Best Tool Type	Hand or grass shears for the clump; snips for spot deadheading
Avoid Heavy Pruning During	Summer heat and drought

Pruning by Plant Age & Size

Newly Established

Minimal — let the crown root and bulk up; remove only damaged foliage, with no shearing in the first season.

Young / Formative

No structural training — a herbaceous clump needs none; simply let it fill out.

Mature / Established

Shear the whole clump back after the main bloom to force a fresh flush of leaves, and lift and divide every three to four years to keep it vigorous.

Seasonal Pruning Schedule

Post-Flowering

After the early-summer flush, shear the clump to near ground level; it regrows a clean mound and often reblooms — the signature cranesbill cut.

Autumn / Winter

Cut back the collapsing, frost-touched foliage to tidy the crown; leave a little cover in the coldest zones.

Ongoing Sanitary

Remove mildewed or slug-chewed leaves and pick off aphid-infested tips.

Structural Pruning & Training

Renewal is by division, not by cutting a framework — splitting a congested crown every few years is the real structural maintenance, keeping the centre from going bare and hollow.

Special Growth to Remove

Spent flower stalks and tired or mildewed foliage. There are no suckers or woody stems to manage; this species clumps rather than running, so there is little spread to contain.

Container & Small-Space Pruning

Keep the clump watered and, where it dislikes heat, shaded in a pot; shear after bloom just as in the ground, and divide when it fills the container.

Tools

Hand or grass shears to cut the whole clump; precision snips for selective deadheading; a spade or fork for lifting and dividing. No woody-plant tools are needed.

Tool Hygiene & Disease Risk

Routine — the main issues are powdery mildew, slugs and aphids, which are cultural or pest problems, so clean blades suffice. If you cut off mildewed foliage, remove it rather than composting in place, but no cut-to-cut sterilising is required.

Cut Placement & Technique

Shear the whole clump low, just above the crown; for selective work, cut spent flower stems back to a basal leaf.

Heavy Pruning & Rejuvenation

Fully tolerated — the entire clump can be sheared to the ground after flowering and will regrow. True rejuvenation of an old, hollow-centred clump is by lifting and dividing it.

Post-Pruning Care

Water well after a mid-season shear, especially in warmth, to fuel regrowth; a little shade aids recovery. No special feeding is required.

Common Pruning Mistakes

• Leaving spent flowers and tired foliage, so the clump looks shabby by midsummer.
• Shearing hard in a hot, dry spell.
• Never dividing, letting the centre go bare.
• Cutting everything to the ground too early in cold zones.

When NOT to Prune

In summer heat and drought stress, and immediately after planting or dividing.

Recommended Tools (by task)

• hedge_shears — to shear the whole clump back after the main flush and at season’s end.
• precision_snips — for selective deadheading of individual flower stems.
• garden_spade — to lift and divide a congested clump for renewal.

Propagation Guide

Bloody cranesbill (Geranium sanguineum) is most easily increased by dividing the clump, with seed as the other option the site lists; it spreads by a shallow, creeping rootstock that pulls apart easily into rooted pieces. Division gives plants identical to the parent, while seedlings of the species come reasonably true but selected colour forms vary. It is easy.

Quick Propagation Specs

Best Propagation Method	Division of the clump
Alternative Methods	Seed; basal cuttings
Propagation Difficulty	Easy
Seed True-to-Type	Species come reasonably true; named forms and hybrids vary
Vegetative True-to-Type	Yes
Best Propagation Season	Spring or autumn

Division, Offsets, Pups & Suckers

Lift an established clump in spring or autumn and pull or cut it into several pieces, each with roots and a few growth buds. Replant at the same depth and keep moist until re-established. This is the standard way to keep a named form true and to rejuvenate an old clump.

Stem Cuttings

Basal Cuttings

In spring, young basal shoots taken with a sliver of the rootstock can be rooted in a gritty, moist mix as an alternative to lifting the whole plant.

Growing from Seed

Sowing Season

Sow in spring; fresh seed sown in autumn also does well for these hardy perennials.

Germination Conditions

Keep the mix moist and cool to moderate; germination of hardy geraniums can be uneven, so be patient and leave the pots undisturbed. Expect seedlings to vary, especially from named or hybrid parents.

Bloom & Edible Flower Guide

Quick Details

• Bloom Season: Late spring through summer into autumn
• Flower Appearance: Flat, open flowers with five petals in pink, purple or white
• Edibility: Edible – the flowers of true cranesbill geraniums are edible with a mild flavour and make a colourful garnish

Detailed Blooming Overview

Geranium sanguineum, the bloody cranesbill, is a tough, mounding hardy perennial that flowers freely over a long season. Its flat five-petalled flowers, most often a vivid magenta-pink, are scattered generously across the finely cut foliage from late spring well into autumn.

Flower Characteristics

• Flat, open flowers with five petals.
• Colours in pink, purple or white.

Bloom Care & Thinning

• Site for best bloom: Full sun to light shade in free-draining soil gives the most flowers; very tolerant and easy.
• After flowering: A shear after the main flush tidies the mound and often prompts more blooms.
• Pollination: Worked by bees and hoverflies.
• Using the flowers: If picking to eat, choose clean, unsprayed blooms and use them fresh as a garnish.

Pests, Diseases & Troubleshooting

Bloody cranesbill is one of the toughest, most trouble-free hardy perennials, with only occasional pests: aphids and slugs (both noted in the source) on soft growth, vine-weevil grubs on the roots of container plants, and sometimes capsid bugs or leafhoppers. Powdery mildew and rust are the main diseases in crowded or stressed clumps. Its chief ‘problem’ is simply flopping open after flowering – solved by shearing back.

Quick Troubleshooting Overview

Issue / Pest	Main Symptom	Primary Solution
Aphids	Colonies and honeydew on new growth	Water-jet, beneficials, insecticidal soap
Slugs & snails	Grazed young leaves, slime trails	Hand-pick, iron-phosphate pellets
Vine weevil	Wilting potted plants, roots eaten by grubs	Check roots, biological nematodes, repot
Powdery mildew	White coating on crowded leaves	Shear back, airflow, remove leaves
Flopping after flowering	Open, sprawling, tired clump	Shear back hard for fresh mound of growth

Common Pests & Management

• Aphids (Aphis / Myzus / Macrosiphum spp.):
  • Symptoms: Small soft-bodied insects (green, black or grey) clustering on soft new growth and flower stems; they suck sap, causing curled, distorted and yellowing growth plus a sticky honeydew that blackens with sooty mould and draws ants. Winged forms spread them plant to plant and can carry viruses.
  • Prevention & Control: Blast colonies off with a firm jet of water and pinch out badly infested tips; encourage and protect ladybirds, lacewings and hoverflies, and grow flowering companions to feed them. For persistent outbreaks use insecticidal soap or a light horticultural/neem oil, wetting leaf undersides in the cool of the evening to spare pollinators.
• Slugs & snails (Deroceras / Helix spp.):
  • Symptoms: Irregular holes in leaves and stems with tell-tale silvery slime trails, worst on soft young growth in damp, shady conditions and after rain or watering; seedlings can be grazed to the ground overnight.
  • Prevention & Control: Clear hiding places, water in the morning so surfaces dry by nightfall, and hand-pick after dark. Set beer traps or ring vulnerable plants with grit, copper tape or crushed shell. Where pressure is high, scatter iron-phosphate pellets, which are safe around pets and wildlife.
• Vine weevil (Otiorhynchus sulcatus):
  • Symptoms: Notched leaf margins from the night-feeding adults, and – far more damaging – fat white C-shaped grubs that eat the roots, causing sudden wilting and collapse, especially of container-grown plants.
  • Prevention & Control: Check the rootball of any wilting potted plant and pick out grubs; drench pots with parasitic nematodes (Steinernema/Heterorhabditis) in mild weather, and hand-pick adults at night. Sticky barriers and gritty top-dressings deter egg-laying.
• Capsid bugs (Lygocoris / Lygus spp.):
  • Symptoms: Small ragged holes and puckered, distorted young leaves where sap-sucking bugs have fed on the growing tips.
  • Prevention & Control: Tolerate light damage, keep beds tidy, and encourage predators; the plant readily grows past the distorted growth without treatment.
• Leafhoppers (Cicadellidae):
  • Symptoms: Pale mottling or flecking of leaves where these jumping insects feed; largely cosmetic.
  • Prevention & Control: Encourage beneficials and tolerate minor damage; insecticidal soap treats heavy infestations.

Diseases & Fungal Issues

• Powdery mildew (Podosphaera / Golovinomyces spp.):
  • Symptoms: White powdery patches on leaves in crowded, dry-rooted or shaded plants, causing yellowing and dieback of foliage.
  • Treatment & Management: Shear the clump back to promote fresh airy growth, space and divide congested plants, keep roots from drying out, and remove affected leaves; sulphur or potassium bicarbonate checks heavy cases.
• Rust (Puccinia spp.):
  • Symptoms: Rusty-brown pustules on leaf undersides with yellow flecking above, in humid weather.
  • Treatment & Management: Improve airflow, remove infected leaves, and avoid overhead watering; sulphur fungicide if persistent.
• Leaf spot / Botrytis (Cercospora / Botrytis cinerea):
  • Symptoms: Brown spots or grey mould on leaves and faded flowers in cool, wet conditions.
  • Treatment & Management: Remove affected foliage and spent flowers, improve airflow, and avoid wetting the leaves.

Growing Difficulties & Abiotic Problems

• Flopping / tired growth after flowering:
  • Cause & Symptoms: After the main flush the clump often opens out, flops and looks tired, with mildew-prone old foliage.
  • Correction Strategy: Shear the whole plant back hard after flowering; it quickly regrows a fresh, tidy mound of leaves and often reblooms.
• Root rot in wet soil:
  • Cause & Symptoms: Though very tough, it can rot in heavy, waterlogged ground, especially over winter.
  • Correction Strategy: Grow in free-draining soil in sun or light shade; it is drought-tolerant once established and dislikes constant wet.

What Helps – Products & Tools

Insecticidal soap or neem handles the odd aphid outbreak, iron-phosphate pellets deal with slugs, and parasitic nematodes are the key ‘tool’ against vine-weevil grubs in pots. For the rare mildew or rust, airflow and a hard shear-back do more than any spray, with sulphur fungicide only for stubborn cases.