Centaurea scabiosa / Greater Knapweed / Perennial Cornflower / Seeds

(Code: ES_117)
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Centaurea scabiosa / Greater Knapweed / Perennial Cornflower / Seeds

Greater Knapweed is a European and British Wildflower and a form of perennial Cornflower.  It has bright purple flowers on strong stems from July to September.  Growing to a height of about 90cm, these look great in a border, grown together in groups or drifts in a cottage or wildflower garden.  These are good cut flowers and attractive to pollinators.   

Greater Knapweed grows best in full sun and well drained neutral to alkaline soils.  The plants are tolerant of tough conditions and poor soils and will self-seed in the right conditions. 


Pack of approx 100 seeds.  Sow the seeds indoors anytime, typically spring to autumn.  Or sow the seeds outside directly into the ground in spring and autumn. Sowing instructions and a colour photo are printed on the packet. 

See how your seeds are packed.

Hardiness Hardy perennial (RHS Hardiness H6)
Flowers July to September
Height 60 - 90cm
Spread 40 - 50cm
Conditions  Grow in full sun to part shade and well-drained neutral to alkaline soils

Sow the seeds indoors anytime, typically from spring to autumn.  Sow the seeds into a tray of compost, cover with compost and keep at 15-20C.  Germination is erratic and takes 1-3 weeks.  Protect summer-sown seedlings in a cold frame or greenhouse over winter and plant out in the spring.  Or sow the seeds outdoors in spring or autumn directly into cultivated soil, thinning the seedlings to about 30cm apart once they are established. 

Grow  Plants grow steadily into clumps from which flower spikes grow in summer.  Mature plants can be divided in autumn and basal cuttings taken in spring.  Plants self-seed in the right conditions and this can be controlled, if necessary, by removing spent flowers before they set seed.