Answering your top 9 questions about flower clocks

Linnaeus and the Flower Clock

Linnaeus and the Flower Clock

Yes, flower clocks are a thing you should know about. We’ll tell you the basics about these beautiful, mysterious, and rare devices.

The basics

Q: What is a flower clock?

Simply put, a flower clock is a clock that uses the blooming and closing of flowers to tell time. Different flowers are arranged in a circular clock-like pattern according to the time of day at which the flowers open or close. So, for example, a dandelion might be planted at 7AM because it opens then (of course, your times may vary).

A classic floral clock is not just a set of hands over a flower bed (though those are also beautiful). A traditional floral clock only uses the flowers’ blooming and closing to tell time.

Q: Do they actually work?

A flower clock works (kind of). The times are imprecise, only hourly, and your mileage may vary depending on external factors like weather, garden care, latitude, and more.

In addition, many of the flowers are similar looking, which can make it hard to read the time.

The history

Q: Who invented the flower clock?

Carl Linnaeus invented floral clocks. You may be familiar with him from biology and Linnean taxonomy. In 1751, he hypothesized about the He based his proposal on flowering times in Uppsala.

Q: When did people start planting floral clocks?

After Linnaeus proposed the flower clock, gardeners began experimenting with it.

However, there’s some speculation that Linnaeus only perfected, rather than invented, the flower clock. Andrew Marvell’s poem The Garden may describe earlier flower clocks in these lines:

How well the skilful Gardner drew
Of flow’rs and herbs this dial new;
Where from above the milder Sun
Does through a fragrant Zodiack run;
And, as it works, th’ industrious Bee
Computes its time as well as we.
How could such sweet and wholsome Hours
Be reckon’d but with herbs and flow’rs!

Q: When were they popular?

Since the 1700s there have been many attempts to build a flower clock. In the 19th century, gardeners frequently attempted to plant the clocks, but differences in flowering times made many efforts fall short. The plans Linnaeus made have to be adapted for different latitudes, flowering times, and seasons.

The science

Q: How does a flower clock work?

Linnaeus laid out the essential factors in his first proposal.

He divided flowers into a few types: Meteorici, which varied their opening and closing times in response to the weather; Tropici, which vary opening and closing times depending on the length of the days; and Aequinoctales, flowers that have fixed opening and closing times. Obviously, only Aequinoctales were appropriate for a flower clock.

Q: Why do flowers open and close at the same time?

No one is certain, at least not yet. Flowers seem to be able to sense the time after the sun has risen, but we don’t know what receptors make it happen.

Floral clocks today

Q: OK, how do I make a floral clock?

If you haven’t been turned off by the difficulties of floral timekeeping, you can find plans online. Remember, you’ll need to adjust for local blooming times, only use aequinoctales, and place flowers at both opening and closing times. The plan provided by the Linnean Society is comprehensive.

After that, you may need some luck.

Q: If I don’t want to make a flower clock, where can I see one?

In the past, the University of Uppsala in Sweden has maintained a flower clock. Before you go, check to see if it’s in bloom and ticking.

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Could a flower clock ever really work? Where would it work best?