Wednesday Weed – Zonal Pelargonium

Pelargonium x hortorum

Dear Readers, was there ever a plant as ubiquitous in municipal displays as the red pelargonium? As I strolled through leafy Muswell Hill today every ancient horse-trough and corner flower bed was stuffed to the gunnels with them. Most of us think of these plants as the ‘true’ geraniums, although this is not technically true: geraniums are those attractive hardy perennials that pop up in semi-shade and flower for ages. This year, pelargoniums have proved their worth during our extended period of hot, sunny weather: they are remarkably drought-proof, probably one reason why the pelargonium is such a stalwart of  shallow-soiled hanging baskets. I think that they look very attractive when  I see them in Austria, dangling from the window boxes, and I can forgive them there because the meadows are so full of plants for pollinators. What annoys me  is seeing them everywhere in city plantings in the UK, because these plants are totally and utterly hopeless for pollinators, like so many bedding plants. If I had my way we would have meadows of thyme and oregano, lavender and rosemary, followed by asters and Japanese anemones and cosmos and single dahlias, but in these days of austerity they are probably too expensive.

The pelargoniums that we see in the UK had their origins in South Africa. In their native land, the flowers of the plant are used as food by several butterfly species, including the Geranium Bronze, whose caterpillars also feed on the leaves and can be something of a pest in commercial nurseries.

Photo One by M.violante 12:38, 28 June 2006 (UTC) - Own work

Geranium Bronze butterfly (Cacyreus marshalli) (Photo One)

There are various groupings of pelargoniums, but the most common bedding ones are known as zonal pelargoniums, because of the patterns in the centre of their leaves, whichs  are derived from one of their ‘parents’, Pelargonium zonale. This wild plant is known as the horse-shoe pelargonium in South Africa because of the shape of its leaves. Its flowers are remarkably like those of ‘our’ pelargonium, except that they are pink, rather than red. The red colour comes from one of the other parents, Pelargonium inquinans. There are various other species in the mix as well, but the result has been a plant that is remarkably long-suffering in exposed, sunbaked sites, although it cannot bear damp conditions and is not tolerant of frost.

Zonal pelargonium – note the pattern on the leaves

Photo Two by By Koppchen - Own work, CC BY-SA 3.0,

Wild Pelargonium zonale (Photo Two)

Photo Three by By Magnus Manske - Own work, CC BY-SA 3.0,

Pelargonium inquinans (Photo Three)

Red pelargoniums have played a role in the story of colour blindness, and how it was first identified. The chemist John Dalton (after whom Daltonism, the technical name for colour blindness, is named) first realised that he didn’t see the world in the same way as other people when, in 1794, he heard people referring to the colour of a red pelargonium that looked either pink or blue to him. He went on to meticulously research the phenomenon, and described how the world looked to him:

‘That part of the image which others call red, appears to me little more than a shade, or defect of light; after that the orange, yellow and green seem one colour, which descends pretty uniformly from an intense to a rare yellow, making what I should call different shades of yellow.’

I have always been fascinated by colour blindness: for one thing, why would it persist in populations if it was a disadvantage? One theory is that colour blindness enables people to see through camouflage more easily, which might have helped both in catching prey and in avoiding being eaten by large striped furry creatures. It’s all very interesting, though I suspect these theories are usually not the whole story. After all, not being able to identify ripe berries would also have been a disadvantage. Colour blindness is also much more common in males, and is seen more frequently in Northern populations – I guess that knocking a walrus on the head with a stick doesn’t require colour vision, and so maybe not being able to distinguish red from green wasn’t a problem. Enough already! My head is gently spinning.

White zonal pelargonium

Pelargonium flowers are said to be edible, but most culinary uses refer to the scented-leaf pelargoniums.  I used to have a big pot of these plants in my front porch (when I had a front porch) and they were a pleasure to brush past with their scents of lemon, chocolate and rose. However, I didn’t know the half of it. You can get scented-leaf pelargoniums that smell of celery, hazelnut, camphor, pineapple and peach and two dozen other things besides. I am half-tempted to start a collection. I know that you can use the leaves for everything from jellies to ice-cream, cakes to tea, and asking visitors to fondle my plants and guess the scent would be an unusual way to get a party started.

Attar of Roses, a scented-leaf pelargonium (Public Domain)

But back to the ‘ordinary’ zonal pelargonium. While many species of pelargonium have been used as a cold and bronchitis cure in their native South Africa, the garden variety seems to be strictly for decorative purposes. However, one interesting side effect of munching on those red petals has been noticed in the Japanese Beetle, a species imported accidentally to the US during the early part of the last century. This insect ( a type of scarab beetle, and rather handsome in my view) has had a lovely time gobbling up roses and crape myrtles, hops and lime trees and about a hundred other plant species with none of its Japanese predators to keep it in check. However, it comes to a sudden stop when it eats the flower of a pelargonium: apparently the chemicals in the plant are very similar to the beetle’s own neurotransmitters, and so it falls to the floor, paralysed. Poor thing. However, I can find no studies that suggest that this has actually been  used as a way of controlling the creature. Presumably, with such a wide range of preferences, it can easily avoid pelargoniums in favour of a potato or a blueberry. I do notice that it also eats Japanese knotweed and poison ivy, however, so perhaps it is not an absolute menace after all.

Photo Four by By Bruce Marlin - Own work, CC BY 3.0,

Japanese beetle (Popillia japonica) (Photo Four)

The potted pelargonium was a favourite of the artist Henri Matisse, who returned to it as a subject again and again. This is an excellent example of working with what you have in front of you, rather than lamenting that one is not in the South of France or New York or halfway up the Limpopo, and therefore can’t find anything to paint/write about. Our ordinary lives are more than rich enough to find inspiration everywhere.

Geraniums by Henri Matisse (1910) – Public Domain

And so, to finish, here is a poem which is sadly very close to my heart. Christian Milne was born in Scotland in 1773, and wrote one book of poetry, ‘Simple Poems on Simple Subjects’ in 1805. The poor lass was a ‘rhymer’ from when she was a child, but was sent into service in Aberdeen at age 14 and it must have felt as if that was that. However, her work was shown to a ‘man of influence’ who enabled her to have the book published, and with it she raised £100, which she promptly invested in a fishing boat for her husband. As she had eight children and was ‘afflicted with ill health’ I find it miraculous that she found the time to write anything at all. It just goes to show that the creative spirit will find a way with the slightest encouragement.

Sent With a Flower Pot Begging a Slip of Geranium

I’ve sent my empty pot again   

 To beg another slip;

 The last you gave, I’m grieved to tell

  December’s frost did nip.

   I love fair Flora and her train

    But nurse her children ill;

    I tend too little, or too much;

    They die from want of skill.

    I blush to trouble you again,

     Who’ve served me oft before;

     But, should this die, I’ll break the pot,

     And trouble you no more.

Christian Milne 1805

Photo Credits

Photo One by M.violante 12:38, 28 June 2006 (UTC) – Own work

Photo Two by By Koppchen – Own work, CC BY-SA 3.0,

Photo Three by By Magnus Manske – Own work, CC BY-SA 3.0,

Photo Four by By Bruce Marlin – Own work, CC BY 3.0,

5 thoughts on “Wednesday Weed – Zonal Pelargonium

  1. tonytomeo

    My primary zonal geranium was found in a neighbor’s trash pile. It is one of the lowly weedy types that we think of as ‘wild’, although they do not really grow wild here. It gets very tall, with bright pink flowers like those in your picture of the wild geranium. I got it while in junior high, and smuggled it back to another home, where the primary plants provided countless cuttings that conditioned the soil where the rose garden is now. I brought pieces with me to every home I have lived in since then. My second geranium was comparable, but with those bright orangish red flowers. It too has been everywhere with me since about 1991.

  2. Toffeeapple

    They seem to have been a constant in my life too; I have only four varieties at the moment including the thuggish, huge red one though my favourite is the tiny delicate, white one, striped with cerise. I now feel the need for a few others…

  3. Pingback: Wednesday Weed – Black Lilyturf | Bug Woman – Adventures in London

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