Does it need to be in water?

It prefers very moist or waterlogged soil but does not require full submersion.

Can it grow in a regular garden bed?

Only if the soil stays consistently wet, otherwise it will struggle.

Plant guide

Lesser spearwort.

Ranunculus flammula

Pronounced ra-NUN-kyoo-lus FLAM-yoo-la

Also known as Lesser Spearwort, creeping spearwort, greater creeping spearwort

Lesser Spearwort — Photo by Henrik S (CC BY) via iNaturalist

This charming little plant is a true lover of wet feet and thrives in boggy spots. You will often find it naturally occurring along the edges of ponds or in damp meadows. It is a lovely choice if you have a water garden that needs a bit of bright color.

At a glance

Care level: Easy
Plant type: Perennial herb
Light: Full sun to partial shade
Indoor light: Direct sun
Water: Every 1 to 2 days
Mature size: 12 to 24 inches
Growth rate: Medium
Hardiness: USDA 4 to 9
Bloom time: Late spring to early autumn

Care

Keep the soil consistently saturated or even submerged in shallow water to mimic its natural wetland home. Watch for wilting, which is a clear sign the soil has dried out too much. It is a hardy grower that does not need much fuss as long as it stays damp.

Watering: The soil must remain constantly moist or waterlogged at all times.
Feeding: A light application of a balanced aquatic plant fertilizer during the growing season is plenty.
Pruning: Trim back dead or yellowing foliage throughout the season to keep the plant looking tidy.
Repotting: Repot when the plant becomes root bound or outgrows its container in the spring.
Soil: Wet, boggy, or heavy clay soils
Soil pH: Neutral to acidic
Temperature: -34 to 30°C
Humidity: 60 to 100%
Drought tolerance: Low
Lifespan: Perennial, typically 3 to 5 years.
Deer and rabbits: Moderate

Signs it needs repotting

Roots growing out of the drainage holes
Stunted growth during the active season

Safety

People: All parts of this plant contain ranunculin, which can cause skin irritation and internal distress if eaten.
Pets: This plant contains ranunculin, which can cause irritation or digestive upset if ingested by cats or dogs.
Children: Keep this plant away from children as the sap is irritating and the plant is toxic if ingested.
Contact allergens: The sap can cause blistering or irritation upon contact with sensitive skin.
Airborne allergens: There are no notable respiratory allergens associated with this plant.
Edibility: This plant is toxic if ingested and should never be consumed.

How to identify it

Small bright yellow five petaled flowers
Narrow lance shaped leaves
Creeping stems that root at nodes
Grows in moist or wet habitats

Height: 0.1 to 0.4m
Spread: 0.15 to 0.5m
Leaves: green, semi-evergreen
Flowers: yellow, 1 to 2cm
Fruit: brown, Late summer

Problems to watch for

Powdery mildew · A fungal infection that appears as white dust on foliage during dry spells.

By symptom

Plant problems by symptom

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Growing it

Propagation: division, seed
When to plant: spring, autumn
Overwintering: The plant is hardy and will go dormant in colder regions. Simply leave it in place, as it will naturally regrow from the roots when spring arrives.
In containers: It grows well in containers placed in water features or kept very moist, using at least a 20 centimeter pot.

Division

1. Carefully lift the plant from the soil in spring.
2. Gently tease the root clump apart into smaller sections.
3. Replant the sections immediately into moist soil.

Group this plant with others that enjoy constant moisture to create a thriving bog garden.

Grows well with

Marsh Marigold · They share a love for the same wet, boggy soil conditions.
Water Mint · It provides a nice textural contrast in damp garden areas.

Similar species

Creeping Buttercup · It has a similar growth habit but is often considered more invasive.

Science

Family: Ranunculaceae
Genus: Ranunculus
Order: Ranunculales
Class: Magnoliopsida
Native range: Europe, Western Asia, and North Africa.
Conservation: It is widespread and not currently of conservation concern.

It survives in wetlands by tolerating saturated soil conditions that would drown many other plants.

Value to wildlife: nectar source
Pollinators: bees, beetles
Uses: pond margins, bog gardens, wet meadow restoration

Through the year

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Flowering

Fruiting

Foliage

Ecological indicators

Salinity: 1/9
Soil reaction: 5/9
Light: 7/9
Temperature: 4/9
Moisture: 8/9
Nutrients: 5/9

Taxonomy resolved against GBIF.

Questions people ask

Does it need to be in water?: It prefers very moist or waterlogged soil but does not require full submersion.
Can it grow in a regular garden bed?: Only if the soil stays consistently wet, otherwise it will struggle.

Where the name comes from

The genus name Ranunculus comes from the Latin for little frog, referring to the wet habitats many species prefer, while flammula means little flame.

Good to know

It is a member of the buttercup family.
The name spearwort refers to the shape of its leaves.
It often roots at the nodes where the stems touch wet soil.

Also in

Plants toxic to cats and dogs

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This guide was generated with AI on October 19, 2026 and checked against GBIF taxonomy. It is general information, not horticultural or veterinary advice. Read about how we build these guides.