Daniel Atha, no rights reserved (CC0) · iNaturalist

1 / 14

Cirsium palustre

marsh thistle

Asteraceae Europe and western Asia

Attracts Pollinators Attracts Butterflies Deer Resistant

SunFull Sun – Part Shade

WaterHigh

HardinessZones 4–8

Overview

Cirsium palustre is a tall biennial or short-lived perennial thistle in the daisy family, forming a spiny basal rosette in its first year and a stiff, erect flowering stem 3-7 feet (0.9-2 m) tall in its second. The stem is narrowly winged and edged with spines along its length, and the lance-shaped leaves are deeply lobed, prickly, and clasp the stem. From summer into early autumn, small flower heads 0.6-1 inch (1.5-2.5 cm) across cluster tightly near the stem tips, each ringed by spiny bracts and packed with dark reddish-purple, occasionally white, disc florets. The heads give way to seeds carried on a feathery pappus that spreads on the wind. The plant grows in marshes, wet meadows, damp woodland, ditches, and streamsides on neutral to acidic soils. It self-sows heavily and has naturalised in parts of North America, where it is treated as an invasive weed in some states. After flowering and setting seed, the plant dies. The spines make it unwelcome near paths and grazing animals.

Native Range

Native to Europe and western Asia, where it grows in marshes, wet meadows, fens, damp woodland, and along ditches and streams. It has naturalised in North America, New Zealand, and other temperate regions, and is listed as a noxious weed in parts of the northern United States and Canada.

Suggested Uses

Grown in wildlife and bog gardens and wet meadow plantings where its nectar-rich heads draw bees, butterflies, and hoverflies through summer. The seeds feed finches and other birds in autumn. In regions where it has naturalised, it is kept out of natural wetlands to limit its spread.

How to Identify

Identify by the tall, narrowly winged, spiny stems and the clusters of small, dark reddish-purple flower heads packed near the stem tips. The deeply lobed, prickly leaves run down the stem as spiny wings. Its wetland habitat and densely clustered, spine-bracted heads separate it from larger-headed thistles of dry ground.

Appearance

Size & Dimensions

Height3' - 7'

Width/Spread1' - 2'

Colors

Flower Colors

Foliage Colors

Fall Foliage Colors

Bloom Information

Bloom Period

~10 weeks

Summer Fall

Dark reddish-purple flower heads open from midsummer into early autumn in tight clusters at the stem tips. Bees and other insects work the heads for nectar. Wind-borne seeds with feathery tufts ripen and disperse from late summer.

Detailed Descriptions

Foliage Description

green

Growing Conditions

Sun Requirements

SunFull Sun SunPartial Shade

Requires 4-10 hours of direct sunlight daily

• Full Sun: 6+ hours of direct sunlight

• Partial Shade: 3-6 hours of direct sunlight

• Full Shade: Less than 3 hours of direct sunlight

Soil Requirements

pH Range5.0 - 7.0(Neutral)

357912

Soil Types

loam silt peat

Drainagemoist

Water & Climate

Water Needs

High

Frost Tolerance

hardy

Time to Maturity

Flowers in second year from seed

Care & Maintenance

Care Guide

Performs in full sun to part shade in consistently moist to wet, neutral to acidic soil at a pH from 5.0 to 7.0. It grows in marshy ground, wet meadows, and damp woodland edges and declines in dry soil. As a biennial it forms a rosette the first year, flowers and seeds the second, then dies. The plant self-sows heavily by wind-borne seed, so it spreads quickly where the ground stays damp and open. It is hardy in zones 4 to 8 and needs no winter protection. Removing seed heads before they ripen is the main way to limit its spread.

Pruning

No pruning is needed for the plant itself. Cutting flowering stems before the seed ripens is the main control on its self-sowing. First-year rosettes can be dug out to stop the following season flowering.