2633. Beyond Blades of Grass

By Paul Bogard, The New York Times, June 16, 2017

Art: Rose Wong, The New York Times.

The other night, mowing my lawn for the first time this spring, I was instantly transported back to my childhood. “I love that smell,” I later said to my fiancée, and didn’t have to explain; we were two suburban-raised Minnesota kids for whom the scent of freshly cut grass has long confirmed winter’s end. Like many an American teenager, I had a monopoly on mowing my neighborhood’s lawns, coming home most summer days with inch-long clippings clinging to socks and grass-stained shoes. I learned to see the perfect lawn as a lush monochrome carpet of Kentucky bluegrass, trimmed and deep green.

I see the perfect lawn differently now. I still see the wide expanses of green, but I also see the high cost of keeping these non-native monocultures growing: the wasted water, the overuse of fossil-fuel fertilizers, the threats to human and environmental health, even to the health of our dogs. Most of all, I see untapped opportunity.

Right outside our door, right beneath our feet lies a chance to make dramatic differences in the health of our human and ecological communities — and save a lot of money. Turf grass (meaning mowed) is now the nation’s largest irrigated crop; we grow three times as much turf grass as we do corn, and far more than any other country. Our turfgrass lawns — including those of corporate campuses and business parks — total 40 million acres, or 60,000 square miles, the size of Georgia. To care for all this lawn, we spend $40 billion annually, more than we spend in direct foreign aid.

What if, instead of seeing lawns primarily as decorative, the more uniform and manicured the better, we saw them as living ground?

Unpaved ground is bursting with life. A teaspoon of healthy soil holds millions of species, and far more microorganisms than there are people on earth. And this isn’t just the soil found in untrammeled nature, but even beneath our busiest lawns. For example, microbial ecologists using DNA sequencing have found — in New York City’s Central Park — a diversity of soil organisms equal to anything they might have found in a tropical rain forest.

But the chemicals we pump into our lawns kill off the upper level of these microorganisms, which then requires us to use synthetic fertilizer to do their job — some 90 million pounds of fertilizer and more than 75 million pounds of pesticides per year. In doing so we create millions of sterile acres.

Insects, especially, pay the price. By now, many Americans have heard about the plight of honey bees and monarch butterflies, but the destruction of the world’s insect life goes much deeper. By some estimates, over the past 35 years, during which the world’s human population doubled, the population of insects declined by 45 percent.

Human well-being relies on the well-being of earth’s biodiversity, and this biodiversity relies in turn on insects and soil. Worldwide, insects pollinate more than 75 percent of our food crops. In the United States alone, insects provide “ecosystem services” such as pest control and nutrient cycling to ensure plant productivity worth an estimated $4.5 billion annually. Ecologically, insects serve as the foundation of countless food chains, essentially the thread that keeps the fabric of ecosystems intact.

But the typical American lawn, a virtual monoculture made of nonnative turf grass, contributes almost nothing to this equation, and in many cases causes it harm. Perhaps what we should ask ourselves is this: Why do we consider neatly trimmed turf grass the pinnacle of what the ground should be? It’s a vision we were taught; for decades, developers actually provided brochures to new suburban homeowners detailing how to make their lawns look like golf course greens. And it’s a vision we can revise.

Instead, we should imagine a perfect lawn as something more than just monoculture turf. No one is suggesting we do away completely with that old ideal. But imagine, in addition, more organic lawns made of pollinator-friendly grasses peppered with clovers, violets, chamomile and other flowering lawn plants; imagine short green turf replaced in places by a diverse wealth of native plants bringing new colors, scents and blooms. In a world of diminishing biodiversity and rapid climate change, the ground beneath our lawns is capable of so much more than just grass.

Already, organizations in several American cities are rethinking “empty” areas of lawn — those expanses of grass surrounding office parks, businesses, government buildings, even individual residences — that could instead be given greater purpose. Imagine if even a quarter of our nation’s turf grass acreage were transformed into native plants and grasses. It would not only add new beauty to our cities, suburbs and small towns, but also protect and nurture the biodiversity on which our ecosystems — and ultimately, our lives — depend.

The turf grass lawn we think of as normal is simply one vision of what the ground around us could be. Numerous sources exist to help property owners looking to transform their lawns, even if that means simply a small patch in an otherwise unused backyard corner. In a world where the question often arises of what one person can do to resist, contribute or make a difference, here is an answer that begins right outside our door.

1764. Why Planting Natives in Your Garden Can Help Save the World

By Douglas W. Tallamy, The New York Times, March 11, 2015

OXFORD, Pa. — I GREW up thinking little of plants. I was interested in snakes and turtles, then insects and, eventually, birds. Now I like plants. But I still like the life they create even more.

Plants are as close to biological miracles as a scientist could dare admit. After all, they allow us, and nearly every other species, to eat sunlight, by creating the nourishment that drives food webs on this planet. As if that weren’t enough, plants also produce oxygen, build topsoil and hold it in place, prevent floods, sequester carbon dioxide, buffer extreme weather and clean our water. Considering all this, you might think we gardeners would value plants for what they do. Instead, we value them for what they look like.

When we design our home landscapes, too many of us choose beautiful plants from all over the world, without considering their ability to support life within our local ecosystems.

Last summer I did a simple experiment at home to measure just how different the plants we use for landscaping can be in supporting local animals. I compared a young white oak in my yard with one of the Bradford pears in my neighbor’s yard. Both trees are the same size, but Bradford pears are ornamentals from Asia, while white oaks are native to eastern North America. I walked around each tree and counted the caterpillars on their leaves at head height. I found 410 caterpillars on the white oak (comprising 19 different species), and only one caterpillar (an inchworm) on the Bradford pear.

Was this a fluke? Hardly. The next day I repeated my survey on a different white oak and Bradford pear. This time I found 233 caterpillars on the white oak (comprising 15 species) and, again, only one on the Bradford pear.

Why such huge differences? It’s simple: Plants don’t want to be eaten, so they have loaded their tissues with nasty chemicals that would kill most insects if eaten. Insects do eat plants, though, and they achieve this by adapting to the chemical defenses of just one or two plant lineages. So some have evolved to eat oak trees without dying, while others have specialized in native cherries or ashes and so on.

But local insects have only just met Bradford pears, in an evolutionary sense, and have not had the time — millennia — required to adapt to their chemical defenses. And so Bradford pears stand virtually untouched in my neighbor’s yard.

In the past, we thought this was a good thing. After all, Asian ornamentals were planted to look pretty, and we certainly didn’t want insects eating them. We were happy with our perfect pears, burning bushes, Japanese barberries, porcelain berries, golden rain trees, crape myrtles, privets, bush honeysuckles and all the other foreign ornamentals.

But there are serious ecological consequences to such choices, and another exercise you can do at home makes them clear. This spring, if you live in North America, put up a chickadee nest box in your yard. If you are lucky, a pair of chickadees will move in and raise a family. While they are feeding their young, watch what the chickadees bring to the nest: mostly caterpillars. Both parents take turns feeding the chicks, enabling them to bring a caterpillar to the nest once every three minutes. And they do this from 6 a.m. until 8 p.m. for each of the 16 to 18 days it takes the chicks to fledge. That’s a total of 350 to 570 caterpillars every day, depending on how many chicks they have. So, an incredible 6,000 to 9,000 caterpillars are required to make one clutch of chickadees.

And chickadees are tiny birds: just a third of an ounce. What if you wanted to support red-bellied woodpeckers in your yard, a bird that is about eight times heavier than a chickadee? How many caterpillars would that take?

What we plant in our landscapes determines what can live in our landscapes. Controlling what grows in our yards is like playing God. By favoring productive species, we can create life, and by using nonnative plants, we can prevent it.

An American yard dominated by Asian ornamentals does not produce nearly the quantity and diversity of insects needed for birds to reproduce. Some might argue that we should just let those birds breed “in nature.” That worked in the past, but now there simply is not enough “nature” left. And it shows. Many bird species in North America have declined drastically in the past 40 years.

Fortunately, more and more gardeners are realizing that their yards offer one of the most empowering conservation options we have, and are sharing their properties with the nature around them.

By the way, you might assume that my oak was riddled with unsightly caterpillar holes, but not so. Since birds eat most of the caterpillars before they get very large, from 10 feet away the oak looked as perfect as a Bradford pear.

Douglas W. Tallamy, a professor of entomology and wildlife ecology at the University of Delaware, is the author of “Bringing Nature Home: How You Can Sustain Wildlife With Native Plants.”