Hay fever sufferers in Detroit have it bad. The city's 84,600 to 114,000 vacant parcels of land are prime real estate for ragweed, a potent allergen. The knee-jerk reaction would be to undertake an uphill battle to keep all of these lots mowed, although the city's sparse resources mean that mowing efforts would be sporadic at best.
Now, however, one research team has discovered that the most neglected and overgrown of those lots are, in fact, a boon to allergy sufferers around the city. Rather than harbor more ragweed, those jungle-like enclosures turn out to be a dog-eat-dog mini ecosystem—one in which the weakling ragweed is quickly choked out.
The researchers performed pollen counts at 62 lots across the city, some of which were mowed once every year or two, and others that had been left completely to their own devices. The team found that just 28 percent of the wildest lots contained ragweed, compared to 63 percent that were mowed once per year and 70 percent that were mowed every other year.
These findings beg the question: should Detroit just give up and let nature take over? As the Atlantic's City Labs reports, "It's uncertain whether letting nature take its course on Detroit's vacant land will help the city's recovery prospects, but the idea is likely to appeal to anyone who dreads the thought of more pollen."