By Tyler Wells Lynch
For years, Toni Genberg assumed a healthy garden was a healthy habitat. That’s how she approached the landscaping around her home in northern Virginia. On trips to the local gardening center, she would privilege aesthetics, buying whatever looked pretty, “which was typically ornamental or invasive plants,” she says. Then, in 2014, Genberg attended a talk by Doug Tallamy, a professor of entomology at the University of Delaware. “I learned I was actually starving our wildlife,” she says.
The problem, Tallamy explained, is with the picky diets of plant-eating insects. Most of these bugs—roughly 90%—eat and reproduce on only certain native plant species, specifically those with whom they share an evolutionary history. Without these carefully tuned adaptations of specific plants, insect populations suffer. And because bugs themselves are a key food source for birds, rodents, amphibians, and other critters, that dependence on natives—and the consequences of not having them—works its way up the food chain. Over time, landscapes that consist mainly of invasive or nonnative plants could become dead zones.
Croplands can be just as destructive, making up nearly 20% of all land in the United States. And that doesn’t even include the single largest irrigated crop in the country. Covering more than 40 million acres in the U.S., grass lawn consumes an area roughly the size of New England—land that, for the sake of habitat conservation, might as well be pavement.
Considering how little habitat and food these monocultures provide, and the incredible amount of resources they require, is there any wonder why the global insect populations are plummeting?
But there are solutions. One, at least in theory, is quite simple: Plant more native species. It’s a calling that has spoken to a growing number of park managers, home gardeners, and landscapers—many of whom trace a direct line of inspiration to Tallamy. His research has helped overturn decades of harmful horticultural practice, forcing us to rethink how we tend to both public and private spaces.