Is this plant invasive?

It can be aggressive in wet, disturbed areas but is generally considered a naturalized weed rather than a primary invasive threat.

Does it need much water?

Yes, it prefers consistently moist to wet soil conditions.

Plant guide

Clustered dock.

Rumex conglomeratus

Pronounced ROO-mex kon-glom-er-AY-tus

Also known as Clustered Dock, Dock

Clustered dock is a hardy perennial herb often found in damp meadows and along stream banks. It produces tall, slender stems with small, greenish flowers that turn reddish brown as they mature. It is quite common in disturbed soils and can be a bit of a nuisance in gardens.

At a glance

Care level: Easy
Plant type: Perennial herb
Light: Full sun to partial shade
Indoor light: Direct sun
Water: Every 2 to 5 days
Mature size: 3 feet
Growth rate: Fast
Hardiness: USDA 5 to 9
Bloom time: Late spring to mid summer

Care

Keep the soil consistently moist as this plant thrives in wet conditions. Watch for aphids on the flower spikes and trim back the stalks after flowering to prevent unwanted seed spread.

Watering: Keep the soil damp at all times to mimic its natural waterside habitat.
Feeding: A light application of balanced fertilizer in spring is usually enough.
Pruning: Cut back the flower stalks after they fade to keep the plant tidy.
Repotting: Repot only if the plant becomes root bound in its container.
Soil: Moist to wet clay or loam
Soil pH: Neutral to slightly acidic
Temperature: -29 to 35°C
Humidity: 40 to 80%
Drought tolerance: Low
Lifespan: Perennial, typically 3 to 5 years
Deer and rabbits: Moderate

Safety

People: Contains oxalates that may cause irritation if ingested in large amounts.
Pets: This plant contains soluble oxalates which can be harmful to cats and dogs if ingested in large quantities.
Children: The plant is not particularly dangerous, but the seeds and leaves should not be consumed by small children.
Contact allergens: Handling the foliage can cause mild skin irritation in sensitive individuals.
Airborne allergens: The wind dispersed pollen may cause allergic reactions in some people.
Edibility: The leaves contain oxalic acid, which can be harmful in large quantities or for individuals with kidney issues.

How to identify it

Whorled clusters of small flowers
Lance shaped leaves with wavy margins
Stems often reddish or purplish
Swollen tubercles on fruit valves

Height: 0.3 to 1m
Spread: 0.3 to 0.6m
Leaves: green, semi-evergreen
Flowers: green, reddish, 0.2 to 0.5cm
Fruit: brown, reddish, Late summer to autumn

Problems to watch for

Rust fungus · Appears as orange or brown pustules on the undersides of leaves.

By symptom

Plant problems by symptom

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Growing it

Propagation: seed
When to plant: spring, autumn
Overwintering: No special care is needed as it is hardy in most temperate climates. Simply clear away dead foliage in early spring to make room for new growth.
In containers: It is not typically grown in containers due to its deep taproot and need for constant moisture.

Seed

1. Collect mature brown seeds in late summer.
2. Sow seeds directly into moist soil outdoors in autumn.
3. Keep the area consistently damp until germination occurs in spring.

Group this plant with other moisture loving species to create a naturalistic bog garden effect.

Grows well with

Marsh Marigold · They both thrive in the same wet, boggy soil conditions.
Yellow Flag Iris · This iris provides a nice structural contrast in similar wet habitats.

Similar species

Curly Dock · It is a close relative with similar growth habits but wavy leaf margins.

Science

Family: Polygonaceae
Genus: Rumex
Order: Caryophyllales
Class: Magnoliopsida
Native range: Europe, Western Asia, and North Africa.
Conservation: It is a common and widespread species with no special conservation concerns.

It colonizes damp, nutrient rich soils and tolerates occasional flooding.

Value to wildlife: larval host plant, seed source for birds
Pollinators: bees, beetles
Uses: wildlife garden, erosion control, wetland restoration

Through the year

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Flowering

Fruiting

Foliage

Ecological indicators

Salinity: 2/9
Soil reaction: 6/9
Light: 7/9
Temperature: 5/9
Moisture: 8/9
Nutrients: 6/9

Taxonomy resolved against GBIF.

Questions people ask

Is this plant invasive?: It can be aggressive in wet, disturbed areas but is generally considered a naturalized weed rather than a primary invasive threat.
Does it need much water?: Yes, it prefers consistently moist to wet soil conditions.

Where the name comes from

Rumex is the ancient Latin name for sorrel, while conglomeratus describes the dense clusters of fruit.

Good to know

The specific epithet conglomeratus refers to the clustered arrangement of the flower whorls.
It is commonly known as clustered dock.
This plant thrives in compacted soil where other species struggle.

Also in

Plants toxic to cats and dogs

Keep your clustered dock growing

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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.