Coleus in Regent’s Park

Dear Readers, when I rented my very first flat, I had no garden. Instead, I became obsessed with house plants. I bought a packet of mixed coleus seeds, and soon there was no corner of the living room or kitchen that didn’t have a gaudily-leaved plant sitting on it. Friends, neighbours, even the postwoman were not safe from having a plastic pot thrust into their hands. What with all the pinching out of the top shoots and the constant watering, it was a busy summer. Sadly, my coleus soon grew leggy in spite of all my ministrations, and they showed a determination to produce their pale-lavender flower spikes (which marked the end of their lives) that was too much for my hard-working, hard-partying ways. Suffice to say that the following year I grew spider plants instead.

But today, as I walked through Regent’s Park, I grew nostalgic. For a sudden splash of colour in a bedding scheme, it’s hard to beat the sheer variety of the coleus, and I suspect that they are good value for money too. Although they are not beloved by pollinators, like other plants, they are also remarkably pest free. Plus, the variety is astonishing. Here are just some of the coleuses (coleii??) that I spotted yesterday:

Lime green with red veins

Burgundy with a yellow edge

Autumnal red

But then I realised that I had no idea whatsoever what a coleus actually was, and there is still some scientific confusion about the plant. It is agreed that the most commonly cultivated variety, previously known as Coleus blumeii, is now known as Plectanthrus scutellarioides. It is a member of the Lamiaceae or deadnettle family, and one common name is ‘painted nettle’. In the ‘wild’, this species is native to a swathe of countries from India in the west to Australia in the south and east. It is a woodland plant which even when not cultivated displays a wide variety of leaf colours and shapes. Here is the ‘original’ plant (here naturalised in Puerto Rico). The small purple-blue flowers look very familiar.

‘Wild’ coleus (Photo One)

Coleus arrived in Europe in 1851, and the US by 1877, but it wasn’t until the 1940s that breeders realised the plant’s colourful potential. By the 1980s the plant was the tenth most important bedding crop in the US. It is a great, cheap, low-maintenance choice for municipal beds, and as anyone who has ever grown them will know they are very easy to propagate by cuttings. Although the plants like high temperatures, their colours are brightest in shade, which is the opposite of my experience with most variegated plants, who need sunshine to keep their colour. Apparently it can be grown as a perennial in colder climates where it shows less tendency to bolt, but in the UK most coleus are used as annual bedding and, as this chromolithograph from the turn of the last century illustrates, it has been this way for a long time.

A chromolithograph of a botanical carpet bedding with a colorful butterfly by Federick William Burbridge (1847-1905). Digitally enhanced from our own original plate. (Photo Two)

Apparently the plant has psychotropic effects, and is used as a hallucinogen by the Mazatec Indians of southern Mexico (their shamans also use psilocybin and Salvia divinorum to conjure visions and enable psychic journeying). I am somewhat surprised as the plant is not native, but it has been very widely naturalised in the Caribbean and Central/South America.

I was fascinated to find that people who grow the ‘wasabi coleus‘ (which has plain acid-green leaves) and the ‘chocolate mint’ coleus (as you might have guessed, brown leaves with green edges) wondered if the plant might taste like their names. The answer, of course, is ‘no’, though it’s a nice idea. There are, however, some species of coleus that are edible, and I’m indebted to the Dave’s Garden website for pointing this out.

One is the ‘country potato’, a group of three coleus species (with Plectranthus rotundifolius being the most important) that are native to Africa but have more recently been grown in southern Asia as well. Their food value comes from their tubers – these are said to be blander than a ‘real’ potato and they are normally used as a subsistence crop, though in Burkina Faso they are milled to produce flour.

Country potato tubers (Plectranthus rotundifolius) (Photo Three )

The other coleus species, Indian coleus( Plectranthus barbatus) is grown, as the name suggests, in India, partially because the root is edible and can be used in pickles, but mainly because the plant contains a chemical compound called forskolin. This has long been used in Ayurvedic medicine, and is sometimes marketed as as a diet aid, because it is believed to burn fat. There is currently no scientific evidence to support this idea, although there are several studies that are looking into the possible medical uses of this plant and several other Asian coleus (you can find extensive information here).

The flowers of Indian coleus (Plectranthus barbatus) (Photo Four)

Now, as you know I am fascinated by the superstitions that grow up around plants. For the coleus, I have had to turn east to the plant’s home range, and here it appears that to have a plant in the house may a) attract bankruptcy, b) attract fire (probably because of the plant’s flame-coloured leaves or c) attract poverty if it starts to bloom in the winter. Coleus is also believed to take revenge on its owner if it isn’t looked after properly. All in all I seem to have had a flat full of trouble, which I then visited on all my friends and relatives. Goodness! Maybe it’s best kept as a bedding plant after all, though to be fair the article that also points out that the coleus has ‘a powerful positive energy and can bring success in business’. I find it difficult to believe that such a bright and cheerful-looking plant can bring many disasters.

And here is a rather fine poem by Richard Swanson, who lives in Wisconsin. Who among us hasn’t tried to protect our garden from the inevitable onset of winter? Some of us (ahem) have been known to sneak out in the soon-to-be-frozen garden with buckets to protect the frogspawn from the promised frost, regardless of what the neighbours think….

Photo Credits

Photo One by By Bjoertvedt – Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=48784530

PhotoTwo by Raw PIxel from https://www.flickr.com/photos/vintage_illustration/43332091102

Photo Three by By Manojk – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=17497669

Photo Four by By mauroguanandi – https://www.flickr.com/photos/mauroguanandi/3197358136/, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=11878867