I grow a few cornflowers most years. They are easy to grow and good for pollinators. Most years I grow ‘fancy’ kinds but this year it was just the very plain blue, as close to the wild cornflower as you can get. Because of the failure of many of the earlier sowings i sowed a late sprinkle of a ‘spare’ packet in cell trays and the seedlings were popped into the annual bed so fill gaps among the mostly orange flowers. The contrast has worked well and makes both colour ‘pop’.

The common cornflower (Centaurea cyanus) is, as might be expected, an agricultural weed that traditonally grew in wheat fields and was considered a pest, though a pretty one. Like most arable weeds it cannot compete with perennial vegetation and benefits from ploughing and other soil cultivation. The seeds do not need light to germinate and can germinate even if buried 8cm deep. They germinate soon after they touch the ground and can geminate in autumn. In fact these are hardy annuals that can be sown either in spring or in September in the garden. Although it was getting scarce in fields, the practice of sowing winter wheat in autumn and rape, suits it. Even so, this annual, which is native to more southern areas of Europe and was introduced to the British Isles about 500 BC is now scarce in the wild in the UK and very scarce in Ireland.

The genus centaurea is in the composite family (Asteraceae) and has a ring of showy, sterile florets around a centre of fertile, less showy florets,

As a garden flower it blooms for several months and it is a good cut flower but I think it has limitations because the branched stems need a lot of picking over to remove the faded old blooms and you inevitably pick lots of buds that will not open in water. The flowers only last three or four days in water. Once flowering is in full swing and especially if the weather is dry, as it has been lately, the plants are usually affected by powdery mildew, in common with most centaureas, although it is not particularly obvious because the leaves and stems are covered in a light down anyway. The blooms are edible and the dried petals are often added to ‘teas’ and other food to add colour.

Cornflowers have lots of other uses and are great for bees and other insects. The flowers have extremely rich nectar with a high sugar content and they seem especially popular with honeybees in this garden, the bees even trying to get into flowers that are not yet fully open. If you leave the plants to die naturally the seeds will drop to the soil to germinate in autumn if finches do not eat them.

A surprising benefit of the plant is that the flowers produce chemicals that attract parasitic braconid wasps that control the larvae of cabbage moths, a pest that affects a wide range of plants. So this may be one of those plants that is actually a useful companion plant. The flowers have been used medicinally in the past.

Because my seed packet was French it was labelled as ‘bleuet’. In the language of flowers cornflowers represents timidity but it has a very different meaning these days in France. Anyone in the UK will be familiar with the use of poppies to remember those who died in France and Belgium in the First World War. After the shelling of the land poppies grew and coloured the landscape, from seeds that had been buried for years and that grew in the disturbed land. The French chose the cornflower which grew in similar profusion for the same purpose although it is also linked to the blue uniforms worn by soldiers. I am not sure if this poem refers to the soldiers or cornflowers but both are bleuets.

These here, these little ‘Bleuets’
These Bleuets the color of the sky,
Are beautiful, cheerful, stylish,
Because they are not afraid.
Merrily, go forward Go on,
my friends, so long!
Good luck for you, little “blues”
Little “bleuets,” you are our hope!

(Bleuets de France, 1916)

To raise money for soldiers, tissue paper cornflowers were made, from 1926, and sold to the public and from 1928 ‘bleuets’ were officially sold to mark Remembrance Day on November 11.

bleuets de france, centaurea cyanus, cornflower, how to grow cornflower