Imagine a clock with no batteries and no mechanical parts. Instead, picture a mini Mexican wave of flowers opening sequentially around a circular bed to map the time – as if the invisible hand of nature was brushing through a cavalcade of unfolding blooms.
Certain plants open and close at a regular time of day, and the idea of arranging them in an order is what gardeners call a flower clock. It was picked up by the New York Times earlier this year; as the article notes, it’s a tricky thing to pull off – perhaps even impossible.
But it’s an irresistible idea, one that’s captivated writers and poets since the days of Andrew Marvell. “How could such sweet and wholesome hours / Be reckon’d but with herbs and flow’rs”, Marvell writes in ‘The Garden’. So I set about ordering the seeds and potting up those species available as plugs to make my own “fragrant zodiac”.
Celandines, pictured, open with the sun. Wordsworth writes in ‘The Lesser Celandine’: “…the first moment that the sun may shine / Bright as the sun himself, ’tis out again!”
18th century Swedish botanist Carl Linnaeus called these time-keeping flowers the aequinoctales. They rarely show up in carpet bedding schemes, because most of them aren’t ‘cultivated’ plants. They’re wildflowers. It’s possible that time-keeping characteristics have been selected out of garden plants in the never-ending search for longer-flowering cultivars and more bankable blooms.
The daisy, which takes its name from the Old English word daegeseage, meaning ‘day’s eye’, opens in the morning (if it’s raining, it’ll stay shut to keep its pollen dry). Dandelions open at approximately 7am, evening primroses at 6pm. European bindweed opens at 5am; with its far-reaching roots, it isn’t exactly a popular choice.
Bringing weeds into the garden is one thing, but getting them to flower is trickier still. An overfed plant simply puts on more and more leafy growth, like a contented caterpillar trapped forever in its larval stage.
‘Evocation’ is the botanical term for the changes that occur in the shoot tip that result in flowering, and it’s a complex operation. Research suggests that the floral stimulus originates in the leaf; the role of day length has been studied intensely. Temperature is another influence. But as the New York Times writes, “the flower obeys its own governor.”
The Iceland poppy, pictured, closes at 7pm. Image credit: Cliff Hand.
Linnaeus came from up near the Arctic Circle. Here, the frozen earth bursts into bloom for a brief period of 24/7 sunlight. So if my Iceland poppies were shy about flowering in a London garden, it isn’t hard to figure out why.
My flower clock never achieved anything like the Mexican wave effect I imagined. Thrilling as it was to see the miniature blooms of the scarlet pimpernel and the pink rock spurrey opening up, they were too sparse and small to have a mass effect. My corn marigolds shot up tall and leggy, my towering chicory put on lots of leaf and dwarfed everything else and my tap-rooted dandelion and salsify never really liked being confined in pots.
But now I’m on familiar terms with the aequinoctales, I find myself looking at them through different eyes. I can see the attraction of a summer trip to the land of the midnight sun to witness the brief riot of wildflowers. Nearer to home, a guerrilla gardening tour of motorway verges and neglected hedgerows will flush out a host of Linnaeus’s aequinoctales.
These plants grow best where they choose to grow. Maybe the way forward is to embrace our little time-keeping weeds in situ and get to know them better.