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cornflowerPropagation & harvesting guides

Please refer to the general growing guide for more in-depth information on growing processes.         

Centaurea cyanus ‘Blue Boy’

Colour: Rich blue blossoms with deep blue centres.

Type: Hardy annual.

Height: up to 90cms

To purchase seeds from this variety please visit our online shop - thank you.

Oh! little boy blue, I won’t be without you!  The most familiar of all the cornflowers is the blue variety and from these ‘Blue Boy’ is one of the best. Long, strong stems produce masses of electric blue flowers. I’ve grown cornflowers every year since the ribbon was cut on our flower farm and I will grow it every year that I am a flower farmer.  I often include other colours - which though are lovely it is always the blue ones that sparkle and twinkle in a bouquet, are requested by customers the most and are literally bought by the bucketful for special occasions.

Their ‘we stand-out because we’re so beautiful and gorgeous’ flowers are a must-have in the cutting garden and are the epitome of ‘cottage style’ flower arrangements. 


Sow seeds indoors from February – March onwards.  Sow into seed compost and cover the seeds.  Germination usually takes place within 2 – 4 weeks.  

Plants are cool hardy, so seeds can be sown in late summer / autumn and planted outdoors about 4 weeks before first frost is due (usually around mid-October).  Seedlings transplanted outdoors in autumn will benefit from frost protection. 


Seedlings can be pricked out of their seed tray as soon as they are big and strong enough to handle. They can then be further transplanted into their permanent position once they have developed a strong, healthy root system.

Cornflower is a cool – hardy plant and it can be planted out when there is still a risk of frost but in areas prone to heavy, prolonged frost would be advisable to use frost protection until danger of frost has passed – usually mid to late May. 


Plants produce tall stems on numerous branches and will definitely benefit from plant support to protect them from wind and rain damage.  The first flush of flowers produced will be on the strongest stems so it would be easy to assume that they don’t require any support – but as further branched stems are a little weaker they will likely tangle together in a big mass and topple over without some support, especially in areas prone to strong winds or during spells of heavy rain.


Cornflowers produces single flowers on individual branched stems.  The first harvest can be taken as single flowers but as stems become more numerous you will find it easier to harvest entire branches at a time, especially as the plant bushes out and becomes denser. By continuously dead-heading (yes, sometimes a tedious chore!) you will be rewarded with a long supply of beautiful flowers.