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common knapweed | Plant Finder | Fill My Garden

Home/Plants/Perennials

Plants > Perennials

common knapweed

Centaurea nigra

Pollinator FriendlyLow Maintenance

Genus: Centaurea
Family: Asteraceae
Common Names: bell weed, black centaury, black knapweed, bowl weed, bull weed, button weed, churl's head, club weed, crop weed, hard weed, hardhead, hardheads, horse knops, horse knots, iron hard, iron heads, iron weed, knob weed, knot weed, lesser knapweed, loggerheads, nob weed, Spanish buttons, sweeps, tassel

About this plant

C. nigra is an upright, branching perennial to 75cm, with simple or pinnately lobed leaves and thistle-like purple flowerheads to 4cm across, with conspicuous blackish involucres

Growing Information

Height

0.5-1 Metres

Spread

0.1-0.5 Metres

Hardiness

Foliage

Deciduous

Growing Conditions

Sunlight

Full SunPartial Shade

Soil

ClayChalkLoamSandy

Acid

Not Currently Available

This plant is not currently stocked at any garden centres on our platform.

Alkaline

Neutral

Moisture

Poorly Drained

Aspect

West FacingNorth FacingEast FacingSouth Facing

Exposure

ShelteredExposed

Care Guide

Cultivation

Prefers a well-drained fertile soil in a sunny position. Tolerant of dry, alkaline soils and established plants are tolerant of considerable neglect. Self-seeds readily and can become invasive

Pruning

No pruning required

Propagation

Propagate by seed

Pests

Generally pest free. Resistant to browsing by deer

Diseases

May be affected by powdery mildews

Garden Uses

Uses

Banks SlopesWildflower Meadow

Season of Interest

SpringSummerAutumn

Size & Characteristics

Height

0.5-1 Metres

Spread

0.1-0.5 Metres

Habit

Clump Forming

Time to Full Height

Five To Ten Years