Hankering for the sky

Caeruleus, the colour of the sky, is as evasive as the sky itself. If the outerspace is full of darkness, then why is the imaginary roof over our heads such a tender and kind shade of pale? Of course, to most decent law-abiding citizen this can be explained with science, but aren't Rayleigh scatterings and wavelenghts dispersal rather dull things? The sky is blue surely because we would find it oppressive if it was purple, enraging if it was red and a bit too monochrome if it was green like the vegetation down below! I adore the true blue colour and as a gardener I have often wondered why it should be so rare in the plant world. There are countless shades of colours in flowers but none the more desirable than caerulea. Most gardeners would give a lot to have a few blue flowers of the Himalayan poppy in their garden - even those who usually overlook poppies altogether. The petals of this perennial have ethereal qualities that mesmerizes who sees it. And I don't escape the enchantment. I have long abandoned the idea of growing the fragile, acid-loving Meconopsis in my windy, chalky garden but I still gasp at the sight of its flowers when I encounter them on one of my visits to Scotland or my native Canada (I'll write more about this later..).
Here I have to resort to other plants for a dose of sky in my borders and by far the best plant to supply me with it is the Delphinium. One of my fondest memories as a burgeoning horticulturist, aged 14, is the sight of a tremendously successful planting of 'Pacific Giants' Delphiniums in my friend Corinne's garden. It was my first summer's work at the local garden centre and Corinne, who also worked there, used to give me a lift in her (interestingly enough) sky blue car. I would cycle to her house and always made sure I did so a little early, in order to have the time to wonder about her garden before we left. The sight of her towering Delphiniums on a dewy summer's morning will always remain imprinted in a gilted sort of way in my mind. I tried to grow them without the success I had hoped for, and then mostly forgot about them until I moved here and inherited a clump of the wonderful 'Lord Butler'. This plant of unequalled stature and beauty rekinkdled my love for all Delphiniums. Never has the higher being offered us a more generous and impressive blue flower to dress our gardens! See it here, pictured with a tall member of my entourage.

One could perhaps compile a short list of true blue flowers - Lithodora diffusa, Corydalis elata, Ceratostigmas, Mertensia sibirica, Omphalodes cappadocica and O. verna, Scilla sibirica, Tecophilea cyanocrocus, Lindelofia, Salvia patens, Muscari 'Valerie Finnis', Lobelia valida, some gentians - but it could by no means be extensive. Still we, gardeners of the temperate world, should think ourselves lucky for the meagre choice that we have - the colour is even rarer in the tropics. I can only think of one truly tropical plant that has pure blue flowers, Convolvulus 'Heavenly Blue'. A couple of other tender plants might be incorporated too - Tweedia caerulea, Plumbago caerulea and Myosotidium hortensia - but they are really subtropicals, so somewhat of a cheat. True blue colour is scarce indeed under the equatorial sun but then who needs blue in flowers where the sky is so intense?