Real Estate

A Viable Alternative to Conventional Lawn? Cornell May Have Found It.

It’s a grail of contemporary horticulture, a subject of inquiry for scientists and landscape designers alike: how to reinvent the estimated 40 million acres of lawn in the United States, shifting the emphasis toward native plants.

The promise? Less environmental damage and more biodiversity.

Because traditional lawn care is, at its essence, a perpetual fight against biodiversity, a war conducted with mower blades and chemicals. All of the numbers — the gallons of water wasted, the tons of pollution generated — tell us to stop.

But what should replace all of that mowed grass? The answer is not easy.

The original native lawn planting at Cornell, in 2009, included more than 20 species of plants, with 11 grasses and sedges among them — a designed plant community modeled after natural grass- and sedge-dominated ones.

The plants were sown, or introduced as small plugs, into ground from which the turf had been stripped, removing a lot of organic matter and fertility. The remaining soil was amended with sand (and limestone dust in a subsequent phase) to make conditions more well-drained and less fertile — the antithesis of what we have offered conventional lawns, and what they rely upon at great environmental cost.

The conditions at Cornell also intentionally disfavored turf-grass weeds, which prefer the rich, loamy soil our lawns typically inhabit.

“That was us tipping the scales to make it less conducive to the turf weeds and more conducive to the native plants,” Mr. Bittner said. “It also created an environment that didn’t require them to be watered and fertilized.”

When going native, prepare for a fluid picture.

As in any natural community, succession rules. Not everything on Cornell’s original plant list has survived — and newcomers have seeded their way in. Various native asters, three species of Viola and beebalm (Monarda fistulosa) are among the many serendipitous arrivals.

The researchers are “embracing benign nonnatives,” Mr. Bittner said, including volunteer white clover (Trifolium repens), self-heal (Prunella vulgaris ssp. vulgaris), St. John’s wort (Hypericum perforatum) and some little buttercups (Ranunculus acris).

“I say benign, but some of them actually provide some benefit, like some pollinator habitat,” he continued. “And what’s actually key in the native lawn is to promote diversity.”

Gone, though, are natives like bluets (Houstonia caerulea), with their low tufts of tiny flowers. Columbine (Aquilegia canadensis) and wild geranium (Geranium maculatum) have also disappeared.

“The Houstonia loved it the first few years. It was phenomenal and breathtaking,” Mr. Bittner said. “It acted as an early successional species, but eventually was outcompeted, we think. But there’s also a role for plants in ecological communities to ebb and flow. You want to have these pioneer species, and then the ones that are going to come on later.”

One perennial that has done especially well is hairy beardtongue (Penstemon hirsutus), whose little lavender-pink tubular flowers can attract an array of pollinators, including long-tongued bees and butterflies, as well as hummingbirds.

Such animal interactions have been a big win. University entomologists report observing nearly four times as many insect families in the native lawn as they do in traditional turf-grass areas. On a single day, they have seen as many as 36 families there.

“We had pollinators, we had herbivores, we had predators, we had parasitoids — this complex web of this insect community that mimicked nature,” Mr. Bittner said. “Which was one of our goals in establishing the native lawn, to create this beneficial native-plant habitat. It far exceeded our expectations, in numbers and complexity.”

The other good news is the sharp reduction in mowing. Once this kind of lawn is established, only a few hours of care is required annually — maybe a cutting or two.

To achieve the look of a lawn rather than a meadow, you mow “to control the height to what you are comfortable with, with however frequent a summer regimen to reach the height you want aesthetically,” Mr. Bittner said.

“Just don’t mow it too short,” he advised, suggesting a minimum of six to eight inches.

One wrinkle is that traditional tools won’t do the job, because their blades can’t be set that high. So get out the weed whacker. This year, the garden staff wielded a scythe, too.

One thing they don’t mow (or walk on): the Eastern prickly pear cactus (Opuntia cespitosa), one of the more surprising New York natives to make itself at home in this new take on the lawn.

Sahred From Source link Real Estate

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