By Christian Paullin, Environmental Journalist
As California begins another round of water restrictions due to the ongoing drought, we will likely start seeing browning lawns, closed golf courses, fewer flowers, and less fruit on trees. But is this necessarily a bad thing? Lawns make up more than 50% of urban outdoor water usage in the U.S. Southwest in the summer months. If more and more home and property owners decided to tear out their lawns and replace them with low-water alternatives, more water would be available for vital uses such as agriculture, drinking water, and there would be enough water to allow our rivers and streams to stay full and provide a healthy ecosystem for native flora and fauna. Does that mean we should all tear out our yards and replace them with gravel or turf? Not necessarily; water usage isn’t the only negative effect of our lawns.
Doug Tallamy is a professor of entomology and ecology at the University of Delaware. His 2020 book, Nature’s Best Hope, focuses on what lawns are doing to our fragile ecosystems across the USA and the world. We tend to confine all conservation efforts to national parks, protected areas, open natural spaces while acting like what we do in urban and suburban areas does not affect those confined natural areas. We
have essentially isolated our open spaces in what Tallamy calls habitat fragmentation.
We already farm and graze 50% of the Earth’s land. The remaining 50% is composed of cities, suburbs, developing areas, and preserved areas. Preserved areas make up only 17% of Earth. We expect that 17% to keep our Earth healthy: recycling carbon dioxide into oxygen, providing habitats for wildlife, supplying fresh water and other resources for the billions of people on Earth, and even providing natural places we can explore and enjoy the natural world.
The 17% of preserved areas are fragmented—separated from other preserved areas by developed areas. This fragmenting is reducing animal and insect populations around the world. Take monarch butterflies, for example; before human development of North America they could migrate unimpeded between Mexico and Canada. As we developed, they could make the journey but numbers dwindled. Now, in 2022, the monarch is an endangered species and its population has declined by more than 80% in the last two decades due to habitat loss. In study performed by Paul Catts at the University of Delaware, the researchers looked at box turtle populations in a 35-acre nature preserve bordered by urban areas. At the start of the study there were 91 turtles. In 40 years the number had dropped to 30. There were other preserved areas nearby with other turtle populations, but the habitat fragmentation restricts these populations to their own fragment and they slowly ran out of mates and resources. Turtles died at a faster rate than births and immigration, leading towards a local extinction. However, if there had been some type of biological corridor between the fragmented preserves, these populations could have thrived.
And this is the crux of Tallamy’s book. We need to start changing our ideas behind lawns. Planting huge grass fields and non-native plants does not provide local animals and insects with the biological corridors that they need to flourish.
Replacing our lawns with local plants, grasses, and trees would be a good start at connecting our fragmented preserved areas. He argues that we need to look at our yards as “homegrown national parks” and that this will help animal and insect populations to reduce population decline across the world.
Tallamy focuses on a few guidelines on turning your lawn into a homegrown national park. We need to:
* Shrink our lawns,
*Remove invasive plants,
*Plant “keystone genera” (local plants that are a major food source for insects), plant species for pollinators,
*Network with neighbors to have similarly curated yards,
*Build hardscape that can benefit animals like a bird fountain and
*Avoid ALL fertilizers, herbicides and insecticides.
You can find native Southern California plants in our own backyard for sale by the Palos Verdes Land Conservancy (https://pvplc.org/plant-sales/). The South Coast Chapter of the California Native Plant Society (https://chapters.cnps.org/southcoast/) has an annual plant sale in the fall. There are also many other nurseries across Southern California specializing in native plants. The California Native Plant Society has an extremely helpful website that allows you to learn about native plants/native plant gardening, provides garden planning software to create a 3D model of your future native plant yard, and lists all native plants available to us in Southern California (https://www.cnps.org/gardening). The best time to plant native plants in Southern California is in fall, just before the winter rains (we hope they will come!). So let your lawn go dormant this summer, then tear it out and plant native plants in the fall.