Greater Knapweed
Centaurea scabiosa
Family: Asteraceae or Compositae
What it is like
Centaurea scabiosa is a PERENNIAL growing to 0.9 m (3ft). See above for USDA hardiness. It is hardy to UK zone 4. It is in flower from July to September, and the seeds ripen from August to October. The species is hermaphrodite (has both male and female organs) and is pollinated by Bees, flies, Lepidoptera (Moths & Butterflies). The plant is self-fertile. It is noted for attracting wildlife. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils, prefers well-drained soil and can grow in nutritionally poor soil. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils and can grow in very alkaline soils. It cannot grow in the shade. It prefers dry or moist soil and can tolerate drought.
Height (m): 0.9
Where it is found
Pastures, field edges and roadsides, usually on chalk.
Much of Europe, including Britain, north to 68° N., east to the Caucasus and W. Asia.
Conservation Status:
Countries/locations it is found in
How it is used
Food
Rating: 0
Medicine
Rating: 2
The roots and seeds are diaphoretic, diuretic, tonic and vulnerary. The plant once had a very high reputation as an ingredient of the Medieval 'salve', an ointment applied to heal wounds and treat skin infections.
Diaphoretic: Induces perspiration.
Diuretic: Acts on the kidneys, promoting the flow of urine.
Tonic: Improves general health. Slower acting than a stimulant, it brings steady improvement.
Vulnerary: Promotes the healing of wounds.
Other
Rating:
Attracts Wildlife: Plants noted for attracting wildlife
How it is grown
Succeeds in ordinary garden soil. Prefers a well-drained fertile soil and a sunny position. Tolerates dry, low fertility and alkaline soils. Does well in the summer meadow. An important nectar plant for bees and butterflies. Members of this genus are rarely if ever troubled by browsing deer.
Propagating it: Seed - sow early spring in a cold frame. When they are large enough to handle, prick the seedlings out into individual pots and plant them out into their permanent positions in the summer. Division in autumn. Very easy, larger clumps can be replanted direct into their permanent positions, though it is best to pot up smaller clumps and grow them on in a cold frame until they are rooting well. Plant them out in the summer or following spring. This should be done at least once every three years in order to maintain the vigour of the plant. Basal cuttings in spring. Harvest the shoots when they are about 10 - 15cm long with plenty of underground stem. Pot them up into individual pots and keep them in light shade in a cold frame or greenhouse until they are rooting well. Plant them out in the summer.
Best place to grow: Meadow; Cultivated Beds;
Habit: Perennial
Hardiness: 4-8
Growth:
Soil: Light (sandy), medium, heavy (clay)
Shade: No shade
Moisture: Dry, moist