By Megan Backhouse
We hear a lot about how gardening is healthy, meditative and therapeutic, but cultivating plants is not without its stresses and one of the chief causes of horticultural disquiet would have to be weeds. Few gardeners are ambivalent about them and these robust and resilient intruders prompt feelings of fervour – both for and against.
In one camp are those who see them as a destructive force crowding out more fragile vegetation. In another are gardeners who embrace their vigor and willingness to grow in even the most hostile spots. Then there are those who tolerate some weeds, pull out others and spray glyphosate on yet others. Or who avoid chemicals but smother weeds with cardboard or mat-forming ground covers or repeatedly douse unwanted plants in boiling water. There's no end to the lengths we can go.
John Dwyer in his Fitzroy garden.Credit: Wayne Taylor
But a new wave of nature writers – including Emma Marris in the United States and Fred Pearce and Richard Mabey in Britain – are calling for a truce, particularly in denuded, hostile landscapes where weeds can help "re-wild" our much-altered planet. In 2015 Pearce wrote a book describing how weeds would be "nature's salvation" and why "for the good of the natural world" we should learn to love them.
Now two Australians have joined the fray, writing books that are sympathetic to ideas of re-wilding but give more attention to the place of weeds in domestic gardens. In Weeds Plants and People, retired Melbourne barrister John Dwyer suggests we make peace with weeds and resist the urge to intervene "unless the case against that particular plant in that particular place is strong". And in The Wondrous World of Weeds: Understanding Nature's Little Workers, herbalist Pat Collins details the culinary, medicinal, biodiversity and environmental benefits of 100 of our most common weeds.
While Collins' text is more of a practical guide (with 300 photographs to help us identify everything from salsify to peppercorn trees), Dwyer delves into the history of and human psychology around weeds. Like Collins he talks about weeds as foods and medicines and argues that we should start to approach them with more of "an open mind".
Part of the issue for Dwyer is the lack of a strict, scientific definition for a weed. He argues we are subjective and inconsistent when it comes to labelling plants as weeds. "We use the word 'weed' to express a range of meanings in a variety of circumstances ... there is no essence of 'weed'," he writes.
Like many of us, Dwyer – who wrote a PhD thesis on weeds – finds himself liking some "weeds" and ridding himself of others. What stays and goes in his gardens (one on Fitzroy and another in the Dandenongs) often comes down to aesthetics and personal philosophy.
He happily cultivates agapanthus but removes self-sown Kangaroo Apple (Solanum lacinatum). He plants masses of daffodils but doesn't always retain the Blackwoods (Acacia melanoxylon) that insert themselves.
He has been battling three-cornered garlic (Allium triquetrum) for a couple of decades, routinely pulls out runners of couch (Cynodon dactylon) from his Fescue lawn and persistently pulls out Oxalis.
But he believes we have over-reacted to the perils of Pinus radiata and have been too quick to remove all willows from the banks of waterways. Indeed, he is increasingly of the view that we have generally become over-zealous about many weeds.
"The more I have thought about weeds, the more I have thought about them as a social construct and felt that the place to look to understand them is not at the plant but at the people," he says.
He is especially troubled by glyphosate, marketed since the 1970s and now the most-used herbicide in the world. Two years ago the International Agency For Research on Cancer, an arm of the World Health Organisation, determined it was "probably carcinogenic to humans". Dwyer says the environmental effects and health risks mean that our "war on weeds" has grown out of proportion.
This is not to say that some weeds don't present serious issues but Dwyer – and Collins – are among those asking us to think about them in a more sympathetic light.
Weeds, Plants and People by John Dwyer, self-published, $49.95; The Wondrous World of Weeds: Understanding Nature's Little Workers by Pat Collins, New Holland, $29.99.