Dandelions

Sunny yellow flowers, toothed leaves, and a seed head that simply begs to be blown are all characteristic of the weed commonly known as dandelion.

Common dandelion flower (Greg Hume) CC BY-SA 3.0

The word dandelion, which means lion’s tooth, actually refers to several different plants in the sunflower family. Native to Europe and Asia, dandelions have been following humanity across the globe, taking advantage of soil disturbed by agriculture, fires, and construction. This makes them a ruderal species. Ruderal species are the first plants to colonize disturbed land.

Bane of lawns everywhere, the common dandelion (Taraxacum officinale) was brought to North America in the 1600s to be used as both food and medicine. The species name officinale refers to an early English word meaning medicinal.

Dandelion in a lawn

Dandelion plants
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Cousin to lettuce and chicory, dandelions are easy to recognize, with their low-growing (basal) rosette of toothed leaves and bright yellow or orange composite flowers. Composite flowers are actually made up of several florets, clustered together. Dandelion florets reflect ultraviolet light, which attracts many beneficial insects, looking for nectar and pollen. Surprisingly, dandelions do not need to be pollinated to set seed. Instead, seeds are produced asexually, in a process called apomixis. As a result, all offspring are identical to the parent plant. Besides the floral stem, dandelions are acaulescent, which means they appear to not have any structural stems.

​Dandelion flowers

Dandelion flowers open each morning and then close each night, in a behavior called nyctinasty. Each plant can produce up to ten floral stems. The cuplike structure seen at the base of each dandelion floret is called a calyculus. Once the flower has matured, it will begin to dry out. After the dried petals and stamens fall off, specialized leaves, called bracts, curve backwards, exposing the seed ball. Each stem produces a single seed ball. These seed balls are commonly called blowballs or clocks. The seeds we see are actually a special type of fruit, called a cypsela. The feathery bristles that act like a sail are called pappi (pappus, singular). The hollow flower stem contains a bitter latex used to defend against herbivores.

Dandelion cypsela (Richard Bartz) CC BY-SA 2.5

​Dandelion latex

Latex is used to make rubber. While most of the latex used to make rubber today comes from the rubber tree (Hevea brasiliensis), you can make your own rubber from dandelion latex! You can make an elastic band simply by coating your finger with dandelion latex, allowing it to dry, and then rolling the latex off your finger. Voilà! You can also make a bouncing ball or waterproof fabric out of dandelion latex. [Did you know that a man named Charles Macintosh figured out how to smear latex between two pieces of fabric to make waterproof fabric? That’s why raincoats are often called macintoshes!] When dandelion latex dries, it stays sticky until it cures. Curing latex involves applying heat and sulfur. The curing process removes the stickiness. Dandelion rubber is stiff in cold temperatures and supple when it is warm. Only Russian dandelions make a latex that is strong enough to be used commercially. [I just learned that one company is researching the use of Russian dandelion latex to make automobile tires!]

Dandelions as food

All parts of the dandelion plant are edible, but you may want to harvest the newest leaves to avoid some of the plant’s bitterness. Eaten the same way as spinach, dandelion greens are packed with good nutrition, including high levels of vitamins A, B, C, and D, according to the University of Maryland Medical Center. Dandelions also contain a lot of iron, calcium, potassium, and zinc. Young dandelion roots can be peeled and eaten. They are said to taste like turnips, but I haven’t tried them yet. The roots can also be roasted and used as a coffee substitute. The flowers are also edible. They can be sautéed in oil with a little garlic and they can be used to make dandelion wine.

Dandelions as medicine

Traditionally, dandelion has been used to treat infections, digestive problems, as a mild laxative, and to stimulate the appetite. Dandelion leaf tea was said to “purify the blood” and the milky latex was used as both mosquito repellent and wart remover, though I couldn’t find any scientific proof to back up any of these claims. According to WebMD, no research has demonstrated any verifiable medicinal use of dandelion, though it does contain chemicals that decrease swelling and increase urine production.

Dandelion roots

These herbaceous perennials have taproots that are strong enough to counteract compacted soil. Hell, they can break through concrete! While dandelion roots are typically only 6 to 18 inches deep, some specimens go 10 to 15 feet deep! Dandelion plants can live for up to 10 years and reach 20 inches in diameter.

I used to try to eliminate dandelions from my lawn, despite my love for their bright yellow flowers and the irresistible seed heads. I finally decided to try putting the plants to work for me in my heavy clay soil. While mulching and growing green manures and cover crops has significantly reduced soil compaction on my property, I have a theory about dandelion taproots. It goes something like this: Since dandelion taproots are strong enough to break asphalt, I allow them to grow, regularly removing the greens (for salads and as a treat for my chickens), before flowers emerge. My theory is that the dandelion taproots will dig down into my compacted soil, bringing microorganisms with them, to create healthier soil. Even if it doesn’t work, I still get pretty flowers and edible greens. Maybe I’ll even try making dandelion wine, one of these days. If my theory is wrong and I end up with a severe problem with dandelions and other, similarly growing weeds, I make have to resort to other control measures.

Dandelion control

If you really must get rid of the dandelions in your lawn, it will take consistent effort on your part. As you already know, those seeds can blow in on the wind from miles away. This battle never ends. While herbicides will certainly kill individual dandelions, those same chemicals can be toxic to other living things, such as us, and our pets. Maintaining a healthy lawn and removing plants as soon as they are seen is the best control method. Cutting off young plants at ground level, a practice called grubbing, is effective only if you are diligent. Crabgrass preemergent herbicides advertised as effective against dandelions do not prevent seeds from germinating.

Love ‘em or hate ‘em, dandelions have been around for 30 million years, and they are here to stay.

You may as well make the most out of these common weeds.