The four o’clock plant – a plant that tells the time. Or should that be “A plant that tells the thyme”?
Now, as you may know, the Victorians loved their bedding plants. Parks and even private gardens would have intricate designs made from flowers and foliage, including clocks.
But this blog isn’t about flowers displayed as a giant timepiece in your garden, although that could be a fun and easy maintenance design for a front garden. (brief design tip – themed planting works well in a front garden, for example, I have previously designed a ‘fan front garden’ for a client who loved fans).
This is about Mirabilis jalapa, the four o’clock plant, a Victorian bedding favourite, but not so often seen nowadays. Plus a few related gardening snippets, which is why I first want to explain why certain plants in our gardens watch their watches.
Can flowers tell the time?
In fact, all plants can tell the time; possibly better than many of us with our dependence on clocks, watches and mobiles for alarms to wake us up.
Perhaps we should be using a dandelion clock? Well, not quite, blowing the seeds off a dandelion head is a more accurate for increasing the spread of the dandelion than telling the correct time by the number of puffs it takes! But when your dahlias start waking up an hour before the sun rises – everyday they’re in bloom, regular as clockwork – and you struggle with the snooze button…how do they do it?
It’s quite clever really. There’s a pigment in the plant that reacts to the increase or decrease in the amount of daylight. Well, to be more precise, it’s the lack of light, ie the darkness of the night that they’re responding to. This enables plants to open their petals at sunrise and close them at sunset. It is also part of the system whereby plants live their lives; for example, knowing when seeds need to germinate and when leaves should fall.
Some flowers are really accurate in their sun watching. For example, young sunflowers track the course of the sun as it moves across the sky, turning those beautiful heavy heads of yellow to mirror the golden globe in the sky. The term for this process is called heliotropism, literally meaning drawn towards the sun.
And whilst other flowers also love the sun, some have particular times of the day when they open their blooms or close their leaves. A favourite of mine is the ‘Four o’clock plant’ or Mirabilis jalapa.
The ‘four o’ clock plant’
Botanically known as Mirabilis jalapa, and also known as ‘Pride of Peru’ and the ‘Marvel of Peru’. Now, the word Mirabilis means “wonderful” in Latin, and it is a wonderful flowering plant. But the second part is confusing in a way, as ‘jalapa’ refers to Xalapa, which is a city in Mexico, not Peru. But then this plant is native to both countries, and it’s likely that both the Incas (Peru) and Aztecs (Mexico) grew Mirabilis jalapa for medicinal and dyeing purposes.
You may look at this South American native at lunchtime and not be impressed. But wait until the late afternoon when it opens its flowers. (Well, it is called the ‘four o’clock plant’!) The flowers have a light citrus scent, which is most noticeable in the evening as the flower wants to attract long tongued hawk moths as pollinators. The flowers will sometimes stay open all night, and may open in the morning on a dull cloudy day.
This beauty can be grown as an annual or a tuberous perennial (like dahlias). It is a stunner in late summer and autumn borders and pots. There are various flower colours and varieties available, including Mirabilis jalapa ‘Alba’ white flowered variety. Also pale pink, bright pink and yellow flowered types. But my favourite combines all of these colours in one plant, with blooms of a single colour, striped and mottled all jostling for your appreciation.
A bit of History
This is one of the oldest ornamental plants to have originated in the Americas that were grown in European gardens. Mirabilis jalapa was introduced into Britain around 1633 by John Tradescant the Younger. However, it was brought earlier to mainland Europe, in the mid–late sixteenth century.
The Tradescants, father and son, were instrumental in discovering many plants from the Americas – the brave new world – and bringing them back to their homeland. As early plant hunters in the Americas, Russia and North Africa we owe many plants in our gardens to their discoveries.
We also owe thanks to the gardeners and botanists who took the seeds and plants and grew or tried to grow these strange herbs and trees in their own gardens and estates. For example, it was growing in the Oxford Physic Garden in the early 1600s and also in the botanist John Gerard’s London garden.
How to grow the four o’ clock plant
The Pride of Peru is generally grown as a tender annual in temperate gardens and is pretty easy to cultivate.
- The seeds can be sown in April in a frost free greenhouse or indoors. They’ll appreciate a little heat if you have it. Sow seeds in individual modules or 4 to a 9cm pot.
- Transplant into bigger, individual pots as needed. These seedlings will need to be grown on under protection and then slowly hardened off before planting outside in the border or containers in June.
- Alternatively, sow outside once possibility of frost has passed, where you want the flowers to grow.
Warning about those Mirabilis jalapa seeds: black and hard coated they look like onion seeds but they’re poisonous, so don’t eat them!
You should be able to buy seeds from various on line outlets and garden centres. Alternatively ask a friend if you see they have the plant with the flower colour you fancy. This is a floriferous perennial and will provide more seeds then one person needs to keep a ‘safety stock’!
Mirabilis jalapa is a tender / semi-tender tuberous perennial plant in the UK. But you may find that if you leave the tubers in the ground that they will over winter if the weather is mild and dry, and your garden is sheltered from the hardest frosts.
Alternatively, grow one or more in pots that you can take into frost free shelter overwinter.
However, it is a good idea to collect seeds as well, so that you can be sure to have your scented, colourful four o clock plant in the garden in the following year.
Where to grow Mirabilis jalapa
The Marvel of Peru is a good border plant for late summer and early autumn, and those multi coloured blooms will certainly give your flower border a ‘zing’! Depending on where you live and how sheltered your garden is, you’ll have flowers from late July through to the first frost.
And you can, of course, treat them as bedding plants in containers or in the ground. Sustainable bedding, perhaps, as you can keep the tubers for many years, and / or grow annually from home collected seed. I’ve found them to be drought tolerant when grown in borders, less so in a pot, but thats to be expected.
And finally
Whilst the four o’clock plant is a fun one to grow, there are more ideas in the blog links below, both of other plants that tell the time plus ideas for autumn borders.
And as for the thyme I mentioned right at the beginning, why not plant it surrounding your ‘four o’clock plant’ in a large container in your front garden? The thyme would add a decorative and subtle contrast and I know it would amuse me to have a “clock” by the front door.
If you’d like help creating autumn planting design for your garden, or have queries regarding your existing garden, do get in touch to ask about our design and consultancy services.
But if you’d prefer hands-on personal help from yours truly, with a mix of practical sessions and theory in our bespoke Gardening Lessons and Courses check out the blog link below plus link for the pdf download with more info
For further gardening advice and inspiration, ideas for pest resistant gardens and more, check out Plews Potting Shed blogs, including the selection below and our monthly Tipsheet You could also come and find us on Instagram Pinterest and Facebook
And on that note, you can have a peek at the progress of my garden renovation, Spitfires and Slow Worms, on Instagram and Facebook You may even get to see it in person later this year / early 2025 as I’m planning a couple of workshops. I had hoped to do that already but house renovations have been as big a thing as garden reno so there hasn’t been the room. Keep an eye on the website and social media for an update
Related Gardening articles you may enjoy from our Award Winning Blog
Sunflowers and the Summer Solstice
Ten Hardy Annual Flowers to Grow From Seed
Flowering Shrubs for Late Summer Colour
Autumn Planting Ideas for Your Garden
