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A picture of a Common Knapweed

Common Knapweed

Centaurea nigra

Also known as

Lesser Knapweed, Hardheads, Bell Weed, Black Centaury, Black Knapweed, Bowl Weed, Bull Weed, Button Weed, Churl's Head, Club Weed, Crop Weed, Hard Weed, Horse Knops, Iron Hard, Iron Heads, Iron Weed, Knob Weed, Knot Weed, Loggerheads, Spanish Buttons, Sweeps, Tassel, Black Starthistle

Full Sun
Moderate watering
Frost Hardy

H6

RHS hardiness

-20°C

Minimum temperature

Expected size

Height
Spread

1m

Max

50cm

50cm

Min

10cm

2 years to reach maturity

Flowering

  • spring
  • summer
  • autumn
  • winter

More images of Common Knapweed

A photo of Common Knapweed
A photo of Common Knapweed
A photo of Common Knapweed
A photo of Common Knapweed
A photo of Common Knapweed

Common Knapweed Overview

This is a perennial with lance-shaped or lanceolate leaves and single clusters of red-purple tubular flowers which bloom in the early summer.

Common problems with Common Knapweed

How to propagate Common Knapweed

Division

You can propagate by seeds or division in the autumn or spring.

Seed

Special features of Common Knapweed

Attracts butterflies

Attracts useful insects

Moths, hoverflies, bees, butterflies

Other uses of Common Knapweed

Waste land