The term “weed” has probably been around since the first human beings attempted to cultivate cereals, i.e. since the Neolithic period. In those days, any plant that didn’t produce edible seeds was undesirable, and therefore “bad”, especially if it monopolized the resources of desirable plants. Incidentally, there are names for these inconvenient plants in every language: “weed” in English, “unkraut” in German, “mala hierba” in Spanish, and so on. But what constitutes a weed changes, sometimes radically, over the course of history.
New France: A Major Culprit in the Introduction of Weeds
Curiously, many of the plants now considered weeds were purposely imported from France in the early days of colonization, in the 1600s. This is because they had been found to have medicinal uses, and so were part of the traditional “jardin de simples” (medicinal plant garden), a garden concept imported by the first hospitals of New France, such as the Hôtel-Dieu de Québec. Dandelion (Taraxacum officinale), for example, was used for its diuretic effects, plantain (Plantago major) for dressings, burdock (Arctium lappa) for its antiseptic effects, and so on.

From New France onwards, dandelion and burdock conquered the whole of America. Plantain established itself so quickly wherever European settlers passed that some Native Americans called it “white man’s foot”. The list of “weeds” in America is full of these strays.
But not all the medicinal plants introduced to the region have been so effective in weeding out. Foxglove (Digitalis purpurea), a highly toxic plant used in many treatments around the old gardens, is still sometimes found, but it never really became a weed. Lungwort (Pulmonaria officinalis), used to treat bronchi and lungs, is well established in the Quebec region, but rarely elsewhere on the continent. Why some plants quickly escape cultivation to become scourges, while others establish themselves without causing much damage, remains a great mystery.
Why So Few Native Weeds?
The vast majority of weeds commonly found in our lawns and gardens are imports from Europe or Asia, brought to America on purpose (as medicinal, forage, vegetable or ornamental plants, etc.) or by accident (seeds traveling in a shipment of wheat, for example).
Why have so few native plants achieved “weed” status? This is largely due to the natural ecosystem of our region: coniferous, mixed or deciduous forest, depending on location.

When the first European settlers arrived here, they discovered forest almost as far as the eye could see, and the native plants were, for the most part, acclimatized to a shady, very stable environment with little disturbance. But Europeans were quick to cut down the forest to establish crop fields, a new environment dominated by sunshine and annual ploughing. Our native, slow-growing, ombrophilous plants were no match for this new ecosystem… but plants from Europe and Asia, where forests had for the most part long since been cut down, had had millennia to adapt to an open, frequently disturbed environment. When they arrived in America, these “field plants” found an environment almost identical to their original one, and proliferated.
In fact, even most of the rare North American plants that have earned the reputation of being weeds originate, not from the dark forests of the East, but from the sun-drenched Prairies. For example, ragweed (Ambrosia artemisiifolia), now well established here, originally came from the Prairies. It gradually immigrated eastwards when the forests were cut down.
Local Weeds

Don’t think that all our weeds come from somewhere else. The beautiful and agressive goldenrod (Solidago canadensis) and common milkweed (Asclepias syriaca) are native to our region, but were rarer in the past, growing only in exposed areas (even the primeval forest had its clearings and other openings, and forest fires caused by lightning, which exposed the soil to the sun, are not new).
With the forest gone, they proliferated, much to the annoyance of farmers and gardeners. Field horsetail (Equisetum arvense) is another native plant that has benefited from the presence of cultivated fields. This cosmopolitan plant (native to almost every corner of the northern hemisphere, from Asia and Europe to America) has become much more common since humans started multiplying it with their ploughs and hoes, as each cut rhizome produces a profusion of new stems.
A Thought Before the Deed
Before pulling out a weed, it’s a good idea to think about the path it took to get to your yard, its distant origins and the many obstacles it had to overcome to get there. After you’ve thought about it for a while, though, pull it out: an unwanted plant is an unwanted plant, and you don’t have to tolerate its presence!

Larry Hodgson published thousands of articles and 65 books over the course of his career, in both French and English. His son, Mathieu, has made it his mission to make his father’s writings accessible to the public. This text was originally published in Le Soleil on August 5, 2006.
Wow, I never knew weeds had such a cool history! It’s amazing how some plants were brought over for medicine but now are just seen as annoying. Makes me think twice before pulling them out! ??
Blue gum, Eucalyptus globulus, is the biggest weed in America, and is unfortunately common in California. I happen to like individual trees, and grow one in my own garden for its aromatic foliage, but must pollard it so that it does not produce seed. I will eventually cut it down and kill the stump, which is no easy task. The species was brought here for railroad ties while railroads were being constructed all over the West.
Learned a great-sounding, new-to-me word from reading this most informative article: “ombrophilous”!