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A picture of a Cornflower

Cornflower

Centaurea cyanus

Also known as

Blue Cornflower, Blue-Bottle, Bachelor's Buttons, Barbeau, Blaver, Blawort, Blue Blaw, Blue Bonnets, Blue Bow, Blue Poppy, Blue Sailors, Blue Tops, Bluets, Break-Your-Spectacles, Brushes, Bunk, Corn Binks, Cornbottle, Corn Centaury, French Pink, Happy Skies, Haw Dods, Hurtsickle, Ragged Robin, Ragged Sailor, Witches' Bells, Corn-Pinks, Thimbles, Witch's-Bells

Centaurea cyanus 20060624120252wp by Albert H. (CC-BY-SA-3.0)

Full Sun
Easy care
Light watering
Frost Hardy

H6

RHS hardiness

-20°C

Minimum temperature

Expected size

Height
Spread

1m

Max

50cm

30cm

Min

30cm

Flowering

  • spring
  • summer
  • autumn
  • winter

This plant has a mild fragrance

More images of Cornflower

Cornflowers (Centaurea cyanus), New Holland, North Lincolnshire
A photo of Cornflower
A photo of Cornflower
A photo of Cornflower
A photo of Cornflower

Cornflower Overview

Centaurea cyanus is a good choice for new gardeners as they are easy to grow and they make great cut flowers. They originally appeared as weeds in grain fields but now more likely to appear in ornamental gardens. Similar to sweet peas, the flowers of this upright annual plant need to be picked constantly to promote continued flowering. It typically grows to a height of around 75cm, producing single, blue flowers measuring around 3-4cm in diameter. These are borne from late spring through to summer. Foliage is simple and oval to linear in shape, sometimes lobed. This species is part of the Royal Horticultural Society “Plants for Pollinators” initiative to showcase plants which support pollinator populations by providing ample amounts of nectar and/ or pollen. A great choice for encouraging pollinating insect wildlife into your garden!

Common problems with Cornflower

White mold, rust, powdery mildew, thread blight. Destroy any plants that become badly infected to prevent it from spreading to surrounding plants.

    How to harvest Cornflower

    Cut flowers just before they are open fully; the centre of the flower should still be dipped inwards slightly.

    How to propagate Cornflower

    Seed

    Sow seeds end of summer about 6 - 8 mm deep. Germination time about 7 - 14 days. Transplant seedlings in Autumn as soon as big enough to handle.

    Special features of Cornflower

    Crop rotation

    Light Feeder

    Attracts useful insects

    Diversity of insects will visit the flowers and help with pollinating neighbouring plantsin the process.

    Other uses of Cornflower

    Culinary, medicinal

    Medicinal

    The petals can be used as a bitter tonic to aid digestion and the leaves as a rinse for scalp eczema.

    Edible

    Fresh flowers can be used in salads or as a garnish. An edible blue dye is obtained from the flowers, used for colouring sugar and confectionary.

    Garden Annuals

    Annuals are mostly, self seeders and flower every year giving you lots of bang for your buck.

    A photo of Floss Flower 'Blue Mink'

    Floss Flower 'Blue Mink'

    Ageratum houstonianum 'Blue Mink'

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