Centaurea dealbata is an attractive clump forming cornflower, with bushy, branched plants and the unusual characteristic of being perennial and flowering in the first year.
Throughout summer, large deep lavender-pink blooms with lighter centers adorn the divided foliage. Like other Centaurea varieties, it is even decorative when in bud, it blooms best if not allowed to dry out and will flower right through August if deadheaded.
The plant is most noteworthy for its divided leaves, the underside being covered in silver hairs. It is very adaptable to both dry and moist locations, and is considered to be drought-tolerant. It is not particular as to soil type or pH and is highly tolerant of urban pollution and will even thrive in inner city environments.
Centaurea dealbata grows to around 75cm (30in) tall at maturity, with a spread of 60cm (24in). In the garden this plant does not require facer plants in front, its foliage remains dense right to the ground.
Very easy to grow from seed, highly attractive to butterflies and bees, an excellent garden plant and the flowers are excellent for cutting.
Sowing: Sow February to May or September to November
Sow seeds in about one month before you want to plant the seedlings outdoors
Fill individual peat pots, seed-starting flats or cells, or 7cm (3in) pot with a commercial seed-starting mix. Moisten the mix and let it drain.
Sow the seeds in rows in the flats. Sow 3 to 4 seeds per pot and cover the seeds with a 1cm (1/2in) layer - centaureas need darkness to germinate. Use a fine spray to moisten the top.
Cover the containers with clear plastic to keep the mix moist while the seeds are germinating and place in a warm location around 16 to 22°C (60 to 70°F). Germination of perennial cornflowers takes 3 to 4 weeks.When the seedlings emerge, remove the plastic covers and put the pots in a sunny location or under grow-lights. Water as needed to keep the mix moist (not soggy).
When the seedlings are about 5cm (2in) tall and have at least one pair of true leaves, snip off all but the strongest plant in each pot at soil level. (The first set of leaves is known as cotyledon leaves—they usually do not resemble the true leaf shapes of the plants.) Fertilise the seedlings once while they are growing indoors with a weak water-soluble fertiliser.
Transplant on a calm, cloudy day, so the plants can begin to get acclimatised before having to contend with sun and wind. Although they are not too particular about fertility, you may want to dig some compost or dried manure into the soil before planting: a 2 to 5cm (1 to 2in) layer should do.
Plant in full or partial sun in any average soil. Give them room to spread, space about 60cm (24in) inches apart. Place them in the mix at the same level they were growing originally. Water the planting well.
Fertilise the plants monthly with a balanced fertiliser or use a slow-release plant food at transplanting time. Water infrequently; Centaurea are drought tolerant, and the stems actually get rather floppy if the soil is too moist. Remove spent flowers to keep the plants producing new blooms.
Division is usually most successful while plants aren’t in active growth in spring or autumn. Keep well-watered afterwards.
Flowers Borders and Beds, Patio/Container Plants, Wildflower Gardens or Wildlife Gardens Cut or Dried Flower. Bee plant, First Year Flowering
Cut and Dried Flowers:
Cut the blooms in early morning when they are half open and strip the lower leaves from the stems. Freshly cut blooms last 4 to 5 days in the vase.
To dry, pick them in late morning or in the afternoon. Select flowers that have just opened or they will drop their petals when dry. Air-dry the flowers: tie in bunches and hang upside down in an airy, dark place for 2 to 3 weeks.
Centaurea is a genus of between 350 and 600 species of herbaceous thistle-like flowering plants in the family Asteraceae. Members of the genus are found only north of the equator, mostly in the Eastern Hemisphere; the Middle East and surrounding regions are particularly species-rich.
Centaurea dealbata was introduced to Britain in 1804; it is widely cultivated as an ornamental, though it is not as well known as some other members of the genus.
Centaurea comes to us from the Centaur Chiron, who cured a festering wound that was made with an arrow dipped in the Hydra's blood. The wound was cured by covering it with the flowers of this plant, which now bears his name as its genus name.
The specific epithet is derived from the Latin verb dealbare 'to whitewash' which refers to the silvery underside of the leaves. It is also known as Psephellus dealbatus.
Common names include Persian Cornflower, Knapweed, Persian Bachelor Button, Persian Centaurea, Whitewash Cornflower and the more ambiguous "bluets". Once upon a time anything that grew and bloomed in a grain field was considered a 'cornflower.' As time passed, that moniker stuck to Centaurea cyanus in particular.
Native to the Caucasus Mountains, ‘Persian’ comes from the fact that this flower originated in Persia, which is now called Iran.
The Plectocephalus group, possibly a distinct genus are commonly known as ‘basketflowers’. And while one sometimes finds the name ‘centauries; this properly refers to the unrelated plant genus Centaurium.
A vernacular name used in parts of England is "loggerheads".
- Additional Information
Packet Size 1 gram Average Seed Count 100 seeds Seed Form Natural Seeds per gram 100 seeds per gram Family Asteraceae Genus Centaurea Species dealbata Synonym Psephellus dealbatus Common Name Persian Cornflower Other Language Names centaurée kornblomst fiordaliso Korenbloem Kornblume chaber Hardiness Hardy Perennial Flowers Large deep lavender-pink blooms Natural Flower Time June to July. Height 75-90cm (30 - 36in) Spread 50-60cm (20-24in) Position Full Sun preferred Aspect West or South Facing. Exposed or Sheltered. Soil Well-drained (Slightly Alkaline preferred) Time to Sow Sow February to May or September to November Germination 3 to 4 weeks