Changing lawns and lawncare practices for biodiversity and health

By Nicole Gerber, Ph.D.

New York State Master Naturalist

Did you know that 83% of all land in the United States is owned by private landowners, and that 40 million acres of land is maintained as turf grass, with 500 square-miles of lawn added each year?

With the sobering statistics on the continuing loss of biodiversity across the globe, people are starting to realize how we are impacting that loss of life (from butterflies to bees, to birds and amphibians) with the common and widespread practices used to create and maintain lawns comprised only of grass.

Human existence relies on the diversity of wildlife that plays critical and unique roles in helping maintain a healthy and balanced ecosystem. What does wildlife need, which also includes all kinds of insects? They need the right types of plants, habitats and healthy environments. This is why learning how you can best manage your lawn and yard to help, rather than hurt, biodiversity will contribute to maintaining a healthy environment for all.

Butterflies and bees are only two types of insects critical to food webs and functioning ecosystems that can greatly benefit from you reducing the amount of turf grass in your lawn, and by your replacing grass with native plants. Native plants are ones that the local wildlife species need, as they provide the right food, shelter and spaces for completing life cycles. Native plants also aid the local environment by helping to provide food, clean water and air, storage of carbon, decomposition, and nutrient cycling. The types of grass species commonly used for lawns are not a food source able to maintain local biodiversity.

A grass lawn provides nothing of value to the bees, moths and butterflies that need specific plants to lay eggs and to provide food for their caterpillars. The importance of caterpillars for bird populations is immensely critical, as caterpillars are one of the main sources of food for baby birds. Studies of bird populations across the U.S. have shown the vital importance of insects for the survival of bird species. It takes thousands of insects to feed one clutch of baby birds, so providing a diverse lawn ecosystem that has the right plants and the right habitat for insects helps birds live and thrive.

Understanding that insects are needed, not only for birds and other wildlife, but for the functioning of entire ecosystems, it is critically important to stop using chemicals in yards. The word “pesticide” is the catchall word meant for the chemicals used to specifically rid yards of weeds (herbicides), insects (insecticides) and fungi (fungicides). The very biodiversity that is being lost and is so needed is right in our lawns and yards, yet chemicals are being applied everywhere and all the time, without regard to their detrimental impacts on animal, environmental and personal health.

Herbicides impact honeybee navigation and make them susceptible to diseases. Insecticides can be non-species specific and kill beneficial insects, as well as those targeted. Yards sprayed for mosquitoes experience diminished plant and overall insect health in the yard. The effect of the spraying also affects neighboring yards, due to chemical drift. Such insecticides have been shown to persist in plants and the environment for months to years after an application, creating long-term, delayed detrimental effects to the plants and soil and to the animals.

The impacts of herbicides and insecticides on human health have also been studied and shown to negatively impact the nervous system, the endocrine system and reproductive outcomes. Research has demonstrated links between bladder cancer and non-Hodgkin’s lymphoma with exposure to herbicides. Forty percent of the pesticide chemicals used in the U.S. are banned in other countries because they have been shown to cause cancer.

Even the health of pets is being impacted by the indiscriminate use of chemicals in yards and neighborhoods. Cancers in dogs have been studied, and it has been found that owners who used herbicide 2,4D had dogs 200% more likely to develop lymphoma. Urine and blood samples of dogs exposed to weed killers show very high levels of the chemical in their systems. As animals, and children, are physically closer to the grass and soil in sprayed yards, their exposure is more direct. Glyphosate is the main chemical in the most common weed killer, RoundUp, and the EPA has reported in a recent evaluation that over 93% of endangered species and 96% of their habitats are likely to be harmed by glyphosate. Along with chemical pesticides, chemical fertilizers have been documented to negatively impact soil, ground water and stormwater. The Environmental Protection Agency (EPA) has stated that 40%-60% of fertilizer applied to lawns ends up in ground water and surface water. U.S. homeowners use about the same amount of chemical fertilizers in their lawns as does the agriculture industry!

The combined impacts of fertilizers and pesticides have made lawns incapable of providing healthy ecosystem services. Homeowners can change their lawns and lawn care practices to build healthy yard ecosystems and promote biodiversity. Such healthy lawn and ecological gardening practices include:

√ Replace lawn and turf grass with native grasses and native plants and create different garden areas in the yard to increase the plant diversity.

√ Stop the use of chemicals – do not use weed killers (herbicides), insect killers or chemical fertilizers – look for organic alternatives and realize that, if the plants and soil are healthy, birds and toads will come and help eat insects that may be considered to be pests.

√ Accept that wild plants that are termed weeds can be beneficial to many pollinators and birds (such as dandelion, clover, plantain, milkweed, goldenrod, Queen Anne’s Lace) – have fun identifying what is in the yard and how it is being used and be creative in maintaining a beneficial wildflower garden.

√ Learn the best mowing practices to keep the lawn grass healthy without chemicals and overwatering – mow high (set mower to three inches or higher) to allow roots to grow longer and the higher grass helps cool the soil surface (reducing water loss and reducing need for constant lawn watering)

√ Leave the grass clippings after mowing, as they provide nutrients to the soil and help cool the soil – healthier lawns have stronger roots and can better withstand drought, competing plants, and resist diseases.

√ Start the lawn mowing later in the season – practice the “No Mow May” concept where preserving the early growing and flowering plants in the yard helps birds, butterflies, bees and other pollinators who need early food sources to survive and grow before summer (many cities across the country are adopting the “No Mow May” concept, including the City of Buffalo!)

Many organizations and initiatives exist to educate landowners on safer lawn practices, reducing lawn, creating pollinator gardens, choosing native plants, and enhancing biodiversity to create healthy yard ecosystems for wildlife and people. Check out the following resources online and enjoy transforming an ordinary grass yard into something beautiful, beneficial, and safe: Xerces Society, Bee City USA, Monarch Watch, Wild Ones, Humane Gardener, National Audubon, Native Plant Trust, Beyond Pesticides.