Dandelion: a useful weed?

Common dandelion (Taraxacum officinale). Image by Franz Eugen Köhler, Köhler's Medizinal-Pflanzen (public domain).

Common dandelion (Taraxacum officinale). Image by Franz Eugen Köhler, Köhler’s Medizinal-Pflanzen (public domain).

I have recently moved house and I now have a small garden to take care of. I’m pretty excited by this prospect and have been trying to decide what to try and grow in it. However, my little garden is currently somewhat overgrown with weeds—most of which are dandelions.

The common dandelion (Taraxacum officinale) belongs to the Daisy family (Compositae/Asteraceae) of flowering plants alongside more popular garden plants such as sunflowers. It is native to Eurasia but has spread to many other parts of the world including North America. The name dandelion derives from the French ‘dent de lion’, which means ‘lion’s tooth’ and refers to the deeply toothed leaves (1).

A common cause of frustration to gardeners, the common dandelion has several features that enable it to be a vigorous weed in most types of soil. Each flower head produces around 2000 seeds in white tufted fruits that form a puffy ball on the plant (so-called “dandelion clocks”). The seeds are dispersed by the wind and can survive dormant in the soil for many years until the conditions are right for them to germinate. Also, the plants produce a taproot that can grow up to 10-15 ft deep into the soil (2). Whole plants can regrow from a small fragment of taproot, which means that it can be very difficult to remove them from your garden.

When I was a child growing up in London, there was a house near me where, rumour had it, a hermit lived by eating the dandelions growing in his back garden. This story is, admittedly, probably just the imaginings of local children, but it isn’t quite as far-fetched as you might think. Dandelions are indeed edible: the leaves can be served raw or cooked and the flowers are used to make drinks including wine or cordial. Even the root is edible, and in the UK it was commonly ground up and to make a coffee substitute during the Second World War (1).

The common dandelion has other useful qualities. It is a diuretic and a laxative and has been traditionally used in medicine as a tonic, for rheumatic problems, and to purify the blood (1). Also, dandelions produce a milky-coloured sap that contains latex (rubber). The demand for latex is fueling research efforts to harvest it from dandelions. These efforts are focussing on the Russian dandelion (Taraxacum kok-saghyz), which produces sap with higher latex content than the common dandelion (3, 4).

So, a plant that is considered to be an annoying weed by many can be considered useful to others. The plant scientist in me does admire dandelions, but that isn’t going to stop me from trying to remove most of them from my flowerbeds. Let battle commence.

Common dandelions in bloom in my garden (Norwich, UK)

Common dandelions in bloom in my garden (Norfolk, UK)

Quite by accident Plant Scientist appears to be having a weed-themed month. Stay-tuned for more posts about plants that often find themselves in the “wrong” places.

In other news, this is the 100th post on the blog. Hooray!

References:

  1. Kew – Taraxacum officinale (dandelion) (retrieved 11/05/15)
  2. UC IPM – How to manage pests: Dandelions (retrieved 11/05/15)
  3. Science Daily – Rubber from Dandelions: Key components in formation of rubber identified. (retrieved 11/05/15)
  4. Science Daily – Making rubber from dandelion juice (retrieved 11/05/15)
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18 thoughts on “Dandelion: a useful weed?

  1. I love dandelions and let them grow wild in my garden along with many other wild flowers, including ragwort (vilified by some but loved by cinnabar moths, which we now see regularly in our sub-urban plot). Dandelions are also loved by pollinators and their seed heads are a valuable source of food for sparrows, gold finches and blue tits. While I understand you might want to make space for other plants in your flower beds – please let the dandelions grow in your lawn (I mow paths rather than the whole lawn, so as to encourage a wide range of native wild flowers).

    🙂

  2. I don’t mind dandelions in moderation but all my flowerbeds are full of them including some of the biggest dandelions I have ever seen – if I don’t dig up most of them they will completely take over. I was planning to leave the ones in the grass anyway 🙂

      • Interesting idea but my garden really is pretty small so not sure I would have enough to keep a pig amused for long. Once I have removed the dandelions from the flower beds I’m intending to replace them with some insect friendly flowering plants that are a bit less vigorous!

  3. Being a native Turkish speaker, I can tell you that the Latin name of the Russian dandelion and perhaps the plant itself, “kok saghyz”, must come originally from a Turkic language area. Kok means root, and saghyz means gum. Chewing gum is called sakiz in Turkish.

  4. I second Huw, dandelions flower quite early in the year and they provide valuable nectar sources for many pollinators like bumblebees and butterflies, also, goldfinches, greenfinches and linnets love their seeds, I very valuable plant we should love and stop calling a weed.

    • Thank you for your comment. I would never agree to a full extermination of dandelions as I agree that in many situations they can be beneficial to insects and birds. However, in my small city garden they have overgrown everything else and I feel that it would be better to get rid of many of them so that I can plant a wider variety of plants that would appeal to wildlife.

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  6. I hav come to realize that , if research would be conducted on weeds , many benefits and solutions for diseases and pests in Agriculture and also health section can be met. am doing a research on how to protect common bean seed from soil borne pathogens and also seed born transfer of infections using different types of weeds. And i am sure i will find solution to this.
    Thank you

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  8. I understand many weeds are the genetic inheritance of ancient agricultural crops and wonder if dandelions with so many attributes might be one of them.Not sure about the ancient uses of latex though!
    I have also been told that rubber was manufactured from dandelions during world war 2.
    They are also interesting in that seed is often, or even usually apomictic

    • Hi Roger,
      Thank you for your comments. I haven’t heard of Dandelions being grown widely as a crop as such, although they were used in traditional medicines so its possible that they were deliberately cultivated at some point I suppose.

      Yes, I’ve heard that too. The Russians started making rubber from dandelions in the 1930s and the UK and other european countries are reported to have used them as an emergancy source of rubber during WW2.

      I hadn’t heard of the seeds being apomictic before. Its a good strategy for a weed though to not need to rely on sexual reproduction though 🙂

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