Despite the fog lifting it has been another very grey, dull day here in Suffolk so a sunflower blog post is a perfect antidote.
Most of the large yellow sunflowers have now faded in the garden and I have spent time today clearing them, leaving the best heads insitu for the birds to peck at the seeds over winter.
Although, the bright yellow sunflowers have now gone over, the beautiful coppery toned ones are still managing to flower really well this week.
The green receptacle at the back of the flower head is also beautiful in it's own right. But not only is it beautiful (and here comes the science bit!) it's responsible for the clever 'trick' of heliotropism i.e. the motion of flower parts. Sunflowers follow the aspect of sun throughout the day and the receptacle allows this to occur. The area where the receptacle and stem meet is called the pulvinus and it contains motor cells. The specialized cells respond to sunlight by pumping potassium ions to change the turgor pressure of cells located in the shade. The biochemical reaction is what causes the flexing and bending of the sunflower to follow the orientation of the sun as the earth rotates. Very clever stuff!
This year I have enjoyed the buds of the sunflower even more than I have the flower.
I love the curved pointed layers of the sunflower (Helianthus Annus) bud. The petals have a muted lime tone to their colouring before they fully develop and the buds have an uncanny resemblance to globe artichokes and yet ironically they are not directly related to the globe artichoke but they are to the Jerusalem artichoke (Helianthus Tuberosus) which bear the same, albeit much smaller flower.
Most of the sunflower is edible, the petals, seeds and even the young buds can be blanched and eaten and apparently taste like Jerusalem artichokes. I haven't yet tried them like this but I will certainly give it a go next year as Jerusalem artichokes and indeed globe artichokes are amongst some of my favourite vegetables despite their reported adverse effects!
Sunflowers petals are also a good source for making a natural yellow dye.
And if you want to keep a little bit of that sunshine over the winter, sunflowers also dry well into golden/mustardy crumpled flowerheads with delicate, brittle leaves.