If you get SAD (seasonal affective disorder) in the winter, some advise a course of light therapy - in-house high-spectrum light full in the face for 30 minutes a day. The idea is that the luminosity will sink into your cells and generate new chemical reactions to cheer you up.
But what do you do if you're SAD at the height of summer, when the sky is already so full of light you have to run from shadow to shadow, hiding your flesh as though from the eyes of an angry god? I find sunflowers help.
Every day I'm accosted by hundreds of them in my neighbourhood, like high-beam happy faces on stalks. Suddenly, I find myself in staring contests with smiling vegetal suns.
Fortunately, one can go head-to-head with a sunflower for a very long time without risking a retina burn. And if a single flower isn't enough, at this time of year you can usually find a crowd of them to arch over you like a little armada of heat lamps the likes of which you'd probably pay a fortune for in a clinic.
Maybe, like Van Gogh, you need to top up on sunflower power.
And if you're an anxious environmentalist, please don't worry about them being an import from Europe. They're indigenous, a gift from the genius of native Americans who have cultivated them for 5,000 years, picking the biggest seeds from the tallest blossoms to get those lofty towers we see today. This has worked well for the birds, especially goldfinches, who use them as space stations. You'll often see them perched near the top, scanning the grasses and gardens for tasty insects. They don't look depressed.
The sunflower is their original bird-feeder. Not only do its 30-centimetre-wide blossoms gather water, but they also produce up to 900 seeds, palatable to birds and humans alike.
Yes, if you really "go sunflower," you'll want to feast on the seeds, too. Sprinkle them on your salads, plant them, make bread. You'll then be truly grounded, at one with First Nations people who used a paste made from these same seeds as travelling food.
You'll also be absorbing healthy fats, protein, fibre, minerals, vitamin E, phytochemicals and, oh yes, tryptophan, a natural antidepressant and sleep regulator. So why not plant a few sunflowers?
But be aware. Once you plant one, they begin to spread like a slow season-to-season conflagration.
You wake up one morning and their little eyes are everywhere, confronting your paranoia, questioning your pallor, your shadiness.
And what beauty. They toil not, neither do they spin; even Solomon in all his glory was not arrayed with so many solar panels so delicately wrought and so nutritious.