Weeds – the great European invasion

As Bee Dawson relates in “A history of gardening in New Zealand”, when Europeans began to settle in earnest in New Zealand in the early to mid-19th century, they not only brought with them “productive” plants,  but many other plants, which soon became invasive “weeds”.

Some of these weeds were introduced accidentally, for instance, as stowaways on or in seed packets of “desirable” plants, while others were deliberately imported, often for their aesthetic and nostalgic value, only to become run-away invaders in an environment and climate entirely different from their country of origin.

A prime example of the latter is gorse. Gorse was introduced as a hedge plant – it was desirable for its vigorous and dense growth and its prolific yellow flowers in summer. As ironic as it may seem today, the first imported seedlings were carefully tended to ensure they were not choked out by ferns or rooted out by wild pigs. But these precautionary measures turned out to be unnecessary – gorse soon began to propagate itself, spreading over extensive tracts of newly cleared land. Other plants that were initially prized, but which later became pests were blackberry, the Scotch thistle, honeysuckle and the Cape gooseberry.

It was not long before provincial government responded to the threat posed by weeds with regulation. In 1854, the Wellington Provincial Council passed “An Act to prevent the propagation of certain plants known as thistles” and in 1861, the provincial council in Nelson passed “An Act to prevent the planting of gorse hedges in the City of Nelson”, under which offenders were liable for a fine of five pounds.

The discussion of weeds leads to the more fundamental philosophical question around what we mean by “weeds”. It is an example of how our perception and interpretation of our natural environment is extremely value-laden. This one word encapsulates the fact that we regard a plant as unproductive, out of place, an annoyance, and often, aesthetically unpleasing – though not intrinsically, but because of what it represents (i.e., an unwelcome nuisance). As such, it is a fairly harsh judgement call about a plant just going about its own business, propagating itself as the environment and climate permits.

This leads to a further question about the universality of the concept of “weeds”. Does the concept of a weed exist in other cultures? In Japanese (an area of my own research), for example, the closest equivalent to “weeds” is the word “zasso” 雑草 , which literally means “miscellaneous grasses” – quite innocent-sounding in comparison, and never (in my experience) used with the level of disdain and contempt as the English word for these hapless plants. Even within European culture, there is a great degree of variability. On visiting Germany a few years ago, I was struck by the refreshingly relaxed attitudes to  grass areas in parks and public areas – rather than being mowed within an inch of their lives, and  “undesirable” herbaceous plants being combatted with selective herbicides, grassed areas are left to grow relatively long and “biologically diverse”, in a way that more resembled a meadow than a manicured lawn.

And, according to ecologist Ian Popay, in pre-European New Zealand also, the Maori vocabulary scarcely acknowledged the existence of a “weed” – there were too few fast-growing annual plants for them to need such a word. In part, this stemmed from the predominant Maori method of horticulture, which involved burning the land to clear it, and growing crops for a few years before allowing the area to revert to bush [see also: Maori gardening in pre-European NZ]. The land was then left for many years before being cleared and cultivated again. Though indigenous, bracken fern (Pteridium aquilinum) was perhaps the nearest thing to a weed that early Māori had to contend with – it would invade cultivated land, which, in addition to depleted fertility, made it necessary for Maori to clear new areas every two or three years. However, bracken would probably not meet the test of a true “weed” by European standards – it was also harvested (and in some cases deliberately cultivated) for its root in late winter, which was an important source of food.

So, the introduction of weeds in the 19th century was not only of the plants themselves, but of a concept – one that was foreign to the indigenous culture.

Photo top: gorse-covered slopes, by B.N. Sullivan. Middle right: Fields near Whitianga. Note the Scotch thistle in the foreground and the gorse in the background. Middle left: gardens on a university campus in Hamburg, Germany. Note the “weeds” in the foreground. Bottom right: bracken fern – New Zealand’s first weed?

Sources: A history of gardening in New Zealand (2010), by Bee Dawson,  Te Ara Online Encyclopedia of New Zealand.

See also: Maori gardening in pre-European NZ

3 thoughts on “Weeds – the great European invasion

  1. Gorse has since shown itself to be one of our most beneficial plants (if you look beyond extreme chemical measures to ‘control’ it), considering its capacity to restore depleted soils, stabilise marginal ground, attract insects and consequently birds, feed bees, nurse fledgling forests and keep pesky humans at bay!

  2. A really interesting read!

    Interesting dialogue about what constitutes a weed and the different cultural perspectives of Japanese and Maori. It does seem like whether something is a “weed” or not depends a lot on your own perspective and what you value.

    And theres a lot of variability too – Some “weeds” are fairly benign and have a range of great attributes while other “weeds” can irrevocably destroy the structure and function of native forest ecosystems.

  3. Thank you for the comment, Meaningoftrees! Yes, it is a salutary reminder that what we regard as a reality is often very relative (and culturally-embedded). You have a great website too – all the best with the research.

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