Summer weeds are a big debate!

HE LOVES its promises of smooth, lazy relaxation. But for Dr Alice Olmsted, an 86-year-old retired legal secretary, springtime in one’s garden can also be a time of renewed dread. That is because Dr Olmsted lives in a suburb of Urbana, Illinois, some 30 miles (48km) east of Chicago. The flowers she usually grows in her own front yard — crocus, geraniums, daffodils, tulips — are in a greenhouse out back. The greenhouse houses a spiky weed known as dandelion, one of the plants at the heart of a lively public debate in the Midwest. “It’s like Hemlock,” says Dr Olmsted, after noticing a large pile of it in her garden. “You laugh about it, and then by the end of the year it’s all over the place.”
Hemlock was the namesake of a garden weed discovered in 1850, and later one of the most thoroughly documented of plant pests: its sole natural predator, the poison-tipped felling knife. In more recent times, it has spread rapidly as hot, dry summers prompt farmers in many parts of the US to rely on irrigation rather than using fertilisers. By spring, the population of dandelions can swell as much as three-fold. The spike makes it hard for the plants to reproduce and is the sole reason they are not called dandelions; the infestation in autumn is a rite of passage for many gardeners. But because the plants do not produce seeds, they do not, technically, harm humans or other animals. Indeed, the toxin they produce — a foul odour that itches and burns, while being poisonous to birds — makes it almost impossible for people to eat them.
But until recently, Dr Olmsted, a denizen of Urbana’s Country Club, did not know this. For years, her garden was well-tended and her planting kept her well supplied with a particular sort of dandelion, which is part of the hybrid strain imported from Europe. In 2017, a neighbour informed her that dandelions had moved into her garden, after which the waste management company contracted to her to deal with the problem (a prerequisite of the homeowner’s insurance policy) dug up large patches of her lawn. Dr Olmsted described her shock at being told that, thanks to the influx of the aforementioned dandelions, the lawn was now infested. “There was just this effect of shock that happened,” she says. “I just didn’t understand it.” It turns out that, thanks to a quirk of Illinois law, the household waste company can use dandelion stems and stalks to generate power. In many households this means disposing of them in the same bin that also contains yard waste, a phenomenon that may get the state hit with a $4.8 million fine, or one-third of its annual revenue, by the time the grand jury that investigated the case has finished its work.
Dr Olmsted is not the only one to have recently been stung by the growth of this invasive weed. In 1997, agricultural scientist Dr Howard Phillips first described dandelions in the US as a significant weed with possible effects on “consumption, agricultural productivity, habitat quality, health, quality of drinking water, and the environment”. Now, as financial insecurity and technological innovations tear apart the country’s landscape, the city of Urbana is doing its bit to stop the spread. It plans to give away herbicides, and install high-tech fertilisers that kill the dandelions long before they can carry out their destructive growth.
To date, a drone has been used to make a highly accurate map of the weeds’ growth, to make sure they are doing things the right way this year. Implementing the plan could cost $5 million to $10 million, according to Urbana’s budget, but the city’s residents already pay as much as $5,000 a year to make sure they are getting the right to discards. The prairie-style city of Urbana has long been a haven for the kind of people who pick tomatoes, enjoy flowering gardens and value its open spaces. But the budget increase it is seeing, in the face of such a large challenge, is without precedent, to say the least. “We’re not trying to solve the problem,” says the city’s mayor, Kirk Schmidt. “But it is a problem.”